Wikipedia talk:WikiProject Elements/Archive 15

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(I'm aware that the title I originally gave this discussion is now quite misleading, as the discussion now covers a much wider scope than just the metalloids, but I won't change it as that would break quite a few links where I or someone else mentioned this discussion.) Double sharp (talk) 08:07, 7 December 2012 (UTC)
(Discussion now continuing at WP:ELEM#Implementing option 10 and WP:ELEM#A tale of seven elements (2013).) Double sharp (talk) 11:17, 6 August 2013 (UTC)

Polonium – metalloid or post-transition metal?

The polonium article states that "Due to its position in the periodic table, polonium is sometimes referred to as a metalloid, however others note that on the basis of its properties and behaviour it is 'unambiguously a metal.'" It has many more metallic properties than non-metallic ones (see Metalloid#Polonium). Shouldn't we be basing our treatment and classification of an element on the basis of its properties and behaviour and not its position in the periodic table? Double sharp (talk) 08:23, 26 June 2012 (UTC)

Yes, certainly, especially since its position in the periodic table doesn't really imply it to be a metalloid IMO. The question of whether it is a metal "based on properties" was already discussed e.g. on Talk:Polonium#Metal_or_Metalloid, BTW. If the evidence is conclusive, I'd support changing polonium to "metal". (However, note that about half the recent sources in List of metalloid lists do consider it to be a metalloid.) --Roentgenium111 (talk) 12:06, 27 June 2012 (UTC)
Po has only metallic allotropes, usually forms Po2+ in aqueous solution, requires very reducing conditions to form Po2− in aqueous solution, forms a weakly basic oxide (PoO2), has moderate electrical conductivity (like Bi), and forms many salts (see Template:Polonium compounds). However, its halides do resemble nonmetal halides in some ways, and many metal polonides (involving the Po2− anion) are known. However, only Na, the alkaline earth metals (except Ra), the lanthanides, and the group 12 elements (except Hg) are known to form ionic polonides; Hg, Pb, and Pt form intermetallic polonides. Double sharp (talk) 14:03, 27 June 2012 (UTC)
Dunno, nonmetal properties don't convince me. Aurides are known, and none calls gold a metalloid. So are bismuthides. And even alkalides. The halides argument can probably be shown in analogy to aluminum. It is also a p-block thing, not only a metal/nonmetal thing, at least to some extent.--R8R Gtrs (talk) 19:27, 27 June 2012 (UTC)
Yeah, I feel the same way too. I suspect the labelling of Po as a metalloid is because they won't let you play around as much with radioactive stuff now as you could get away with in the 60s and 70s. :-( So people don't know so much about its chemical properties and just give it a default metalloid status as it's next to the "metalloid line". (At, although also next to the metalloid line, isn't defaulted to being a metalloid as much, because it's also in group 17 and tends to instead be defaulted to being a halogen – it's in astatine and metalloid, and you probably know more than me about At anyway. ;-)) Double sharp (talk) 14:36, 28 June 2012 (UTC)

Consistent with the above observations, I struggle to find sufficient grounds for classifying polonium as a metalloid. It shows a few nonmetallic or intermediate properties but these are 'trumped' by its metallic properties, especially the combination of: metallic band structure; metallic conductivity; the presence of a polonium cation in mildly acidic aqueous solution; and the basicity of its oxide. Polonium would be better classified as a post-transition metal. As you note R8R, the nonmetallic properties of polonium are found in, for example, some of the transition metals yet these are not classified as metalloids.

Astatine suffers from having a relatively obscure chemistry. Per Double sharp, this means that it tends to inherit the default nonmetal status of its lighter halogen congeners. Apparently halogen membership trumps being next to the metal-nonmetal dividing line, artificial as the latter construct is. OTOH, reading selectively from the literature:

  • Bresler (1952) comments that, 'the properties of the metal and the halogen are curiously combined in this element.'
  • Edwards and Sienko (1983) speculate, on the basis of the Goldhammer-Herzfeld criterion for metallicity, that astatine is probably a 'semimetal' (i.e. a metalloid).
  • Rössler (1985) highlights 'the chemical ambiguity of astatine between halogen and metal character.'
  • Siekierski and Burgess (2002) contend or presume that astatine would be a metal if it could form a condensed phase—but do not give a specific basis for their claim.

Against this background, and noting...

  • (1) its currently known and estimated properties
  • (2) the transition from 'nonmetal-with-incipient-metallic-properties' (NWIMP) to metalloid, in the neighbouring elements selenium and tellurium; and
  • (3) the NWIMP status of iodine,

...astatine is currently better classified as a metalloid. IMPs of iodine include: residual metallic luster; semi-conductivity (band gap = 1.35 ev); photoconductivity; electron delocalization within the layers of the solid iodine lattice; its metallic transformation under the application of relatively modest pressure; the metal-like electrical conductivity of the liquid form; the existence of the +1 iodine cation in pyridine solution and associated salts; and the polymeric structure of its most stable oxide, I2O5.

  • Bresler SE 1952, Radioactive elements, 2nd ed., State Technical Theoretical Press, Moscow, in IM Korenman 1959, 'Regularities in properties of thallium', Journal of general chemistry of the USSR, English translation, Consultants Bureau, New York, vol. 29, no. 2, pp. 1366–1390 (1368)
  • Edwards PP & Sienko MJ 1983, 'On the occurrence of metallic character in the periodic table of the elements,' Journal of Chemical Education, vol. 60, no. 9, pp. 691–696 (692)
  • Rössler K 1985, ‘Handling of astatine’, in HK Kugler & C Keller (eds), Gmelin handbook of inorganic chemistry, At Astatine, 8th ed., Springer-Verlag, Berlin, pp. 140–156 (143)
  • Siekierski S & Burgess J 2002, Concise chemistry of the elements, Horwood, Chichester, pp. 65, 122

Sandbh (talk) 07:31, 1 July 2012 (UTC)

I would agree with colouring Po as a post-transition metal and At as a metalloid, but what do we do with the halogens category? For, after all, At is both a metalloid and a halogen! (The German compact periodic table template has a nice solution...) Double sharp (talk) 11:40, 2 July 2012 (UTC)
Going through all the periodic table templates and changing Po to a post-transition metal everywhere. This is extremely patience-exhausting. (We then need to figure out what to do for At's metalloid status. The most drastic plan would be to get rid of the "halogens" category, but that would be too drastic for my tastes.) Double sharp (talk) 15:03, 2 July 2012 (UTC)
Finally finished updating Po in all the templates. I might have missed a few, in which case you are free to fix it without telling me. Now we can talk about At. Double sharp (talk) 15:13, 2 July 2012 (UTC)

Astatine – metalloid or halogen?

I'm fairly convinced that At deserves to be called a metalloid, but that would clash with its (also relevant) halogen status. What do you propose? (Getting rid of the "halogens" category would solve the problem, but would be far too drastic for my tastes.) Double sharp (talk) 13:15, 3 July 2012 (UTC)

If the current post-transition, metalloid and 'other nonmetal', categories can obliterate the pnictogen and chalcogen categories then I'm not sure if there is a need to treat the halogens differently (a preference is fine, but not the same as a need). For astatine, could it be shown as a metalloid but in the Element category box for the astatine article, change the name of the box to 'Element categories' and then enter two categories i.e. 'metalloid; halogen'? Same approach could work for e.g. gold: 'transition metal; noble metal; coinage metal;' or bismuth: 'post-transition metal; pnictogen'. — Preceding unsigned comment added by Sandbh (talkcontribs) 13:04, 4 July 2012 (UTC)
Here's a halogen-less periodic table:

Double sharp (talk) 14:53, 4 July 2012 (UTC)

The German Wikipedia solution has an image used as the background with both possible categorisations shown (alternating bands of the halogen and metalloid colour). This could be a useful idea for the compact table, but I'm not sure if it can work for any cell size. Double sharp (talk) 14:56, 4 July 2012 (UTC)
Then again, the halogens are a very good example of group relationships (along with the alkali metals and noble gases). It would be a shame if they had to go. (The pnictogens and chalcogens do not show particularly strong group relationships.) Double sharp (talk) 11:27, 5 July 2012 (UTC)
I was going to say that if this ends up going anywhere then the template should still include yellow shading somewhere. However, and I don't know why, this color scheme is beginning to grow on me. The argument about the halogens showing particularly strong group relationships is a good one. I think my counter argument is that the proposed categorization scheme is more consistent in terms of its logic. To add something else to the discussion I'll see if I can at least post a depiction of what the proposed template would look like. Sandbh (talk) 12:45, 6 July 2012 (UTC)
How's the German one?

Double sharp (talk) 13:43, 6 July 2012 (UTC)

I edited it slightly above; the original version is at de:Vorlage:Navigationsleiste Periodensystem. Double sharp (talk) 13:46, 6 July 2012 (UTC)
I like/was pleasantly surprised by the fact that you can add images? to the cells to get the striped effect. I think the execution of this idea could be improved though. Just use divide the cell using a simple diagonal, for example. Sandbh (talk) 03:09, 7 July 2012 (UTC)
I expect that a simple diagonal, whichever direction, will disturb the look of the table. It could suggest there is a sort of diagonal group running through it. Although most will known or learn what it really means, that is what the pattern structure as recognised suggests. In this table size, the 2+2 hatches and their direction look right to me. (Oh and this is somewhat preliminary: please take a look on what the dark German colors do. Text is less readable as you´ll notice, it gets more like a chaptke, especially with the hatching. But that is for when we would use these dark backgrounds). -DePiep (talk) 08:15, 12 July 2012 (UTC)

I think the halogens should be kept on the table. They are distinctly different from other nonmetals, and have their own chemical properties. However, in the case of astatine, I like the idea that was proposed in the Polonium--Metal or Metaloid section: See whether astatine has more metaloid or halogen properties. King jakob c (talk) 14:48, 17 August 2012 (UTC)

At is more of a metalloid than a normal halogen, but it is still technically a halogen, so it doesn't really make sense to colour F, Cl, Br, and I as halogens and At as a metalloid, because the halogen group extends to At. The halogens don't show the strongest group relationships – there is still the nonmetal-through-metalloid-to-metal trend that you see when going down the p-block, whose effects are first seen at I and At. The other groups marked (alkali metals, alkaline earth metals, and noble gases) don't show such trends for their elements. Periodic trends for the halogens are typically shown for only F, Cl, Br, and I. As R8R Gtrs says in the next section, although the reason may vary from author to author, At is usually not included, and statements purported to be about the halogens may actually only apply to F, Cl, Br, and I. Double sharp (talk) 06:23, 18 August 2012 (UTC)

Eight category table

As flagged, here's a table that addresses the problems with the categorization of Al and At, and retains and expands the presence of group names:

Eight category periodic table (Mk2).png

Non-standard colour scheme. An old one I found in my files; haven't spent any time seeing if it could be improved.

Pre-transition metals. As used in the literature. Cox (2004, pp. 185–186) is a good example.

Rare earth metals. I've used this as a category name given it's more popular than 'lanthanides'. Google returned 1,170,000 hits for rare earth metals and 739,000 for lanthanides.

Poor metals. No accepted short-hand term exists for the well-documented notion of a bunch of 'second string' metals characterized by physically and chemically weaker metallic properties, and which generally occupy the region between the transition metals and the metalloids. I agree with Double sharp that 'poor metals' is a reasonable title for this category, given the problems with the alternatives e.g. 'B metals'; 'B subgroup metals'; 'chemically weak metals'; 'metametals'; 'other metals'; 'post-transition metals'; and 'semimetals'. [That being so, I like the old school feel of 'B subgroup metals' and could go with it as long other editors wouldn't see too much of a clash with the 'type a | borderline | type b' categorisation construct for the behaviour of metal ions.]

I've shown Be, Al, Cu, Ag, Au and Lr as partly belonging to this category. The non-metallic properties of Be (metallic-covalent bonding structure; predominately covalent chemistry; amphoteric oxides; anionic beryllate formation) are cited in the literature. Rayner-Canham and Overton (2006, pp. 29–30), for example, categorize Be as a chemically weak metal (ditto Al). For the latter, see also Metalloid#Aluminium. The elements Cu, Ag and Au are transition metals, and are included here in cognizance of the main-group chemistry of their univalent compounds; general tendency to form covalent compounds; and amphoteric oxides. Phillips and Williams (1966, pp. 4–5), for example, categorize Cu, Ag and Au as transition metals as well as B-metals. Lastly, I've counted Lr as being partly a poor metal on the basis of its predicted electronic structure of [Rn] 7s2 5f147p1 rather than [Rn]7s25f146d1.

We can discuss whether the Group 12 metals ought to instead be counted as transition metals. As I understand it, they aren't much chop physically in comparison to the transition metals proper, and chemically they're overwhelmingly not transition metals.

Core metals. No accepted short-hand term exists for the well-documented notion of a set of 'garden variety' nonmetals, between the metalloids and the noble gases. Accordingly, I suggest the descriptive title/phrase 'core metals' for this category, consistent with Wikipedia:Wikipedia is not a dictionary#Neologisms.

Group 3 membership. After thirty years, Jensen's argument (1982) for the placement of Lu and Lr in Group 3 still stands, and is better, in terms of its eloquence, than anything else on offer.

Metal-nonmetal line. I've positioned this above the centre of the metalloid category box rather than between the poor metals box and the metalloids box. I'm still in two minds as to which way would be better.


  • Cox PA 2004, Inorganic chemistry, 2nd ed., Instant notes series, Bios Scientific, London
  • Jensen WB 1982, 'The positions of lanthanum (actinium) and lutetium (lawrencium) in the periodic table', Journal of Chemical Education, vol. 59, no. 8, pp. 634–636
  • Phillips CSG & Williams RJP 1966, Inorganic chemistry, II: Metals, Clarendon Press, Oxford
  • Rayner-Canham G & Overton T 2006, Descriptive inorganic chemistry, 4th ed., WH Freeman, New York

Sandbh (talk) 14:06, 20 July 2012 (UTC)

First reation. I am new to the WP:ELEM community, but being a technical one I can understand the discussions.
  1. You talk about naming the categories: "poor metal" or "post transition metal"
  2. Colors: agree colors should follow their legend meaning, no problem.
  3. You talk about mix-grouping elements. e.g. Aluminium (Al) you mix-group (hatch) different compared to the Double sharp (German) table above.
Colors and hatching and names, really, we can find later. Main problem: As long as there is no agreement on positioning (grouping) of mixed-category elements, there is no use talking about colors or hatching. I suggest the WP:ELEM community aim for a consensus on these mixed-category (and so mixed color) elements. I know it is old & tough, but isn't solving that what we are here for? -DePiep (talk) 21:03, 20 July 2012 (UTC)
Here are my thoughts:
  1. Pre-transition metals: I still feel that the alkali and alkaline earth metals have such strong group relationships that they ought to be separated. Ditto for the halogens (which was why I was torn between putting At as a metalloid or halogen in the first place).
  2. Lanthanides/Rare earth metals: Technically, rare earth metals also includes Sc and Y, while lanthanides doesn't, so they're not exactly the same. (And I like the parallel between lanthanides and actinides.)
  3. Poor metals: No problems for me.
  4. Lr as a poor metal: But the Lr article states that it behaves chemically more like Lu and the actinides than Tl.
  5. Group 12: Here's an old discussion on the same thing. If we put Zn and Cd as post-transition (poor), then what do we do about Hg and Cn? Hg forms HgF4, and if one compound isn't enough (as Jensen states, and I also lean towards that position), Cn is predicted to show mainly the +4 oxidation state.
  6. Core nonmetals: I still feel somewhat uncomfortable with that term. "Other nonmetals" is far more obvious IMHO (it shows that the halogens and noble gases are also nonmetals, and that these are just the nonmetals that aren't under any other category used) and doesn't make people think that "core nonmetals" is a very standard term. I can see though that since these are the most ordinary nonmetals, "other nonmetals" might also mislead people into thinking that they're not ordinary nonmetals, so this isn't a very strong position. Don't know for sure what to do about it: maybe we should wait for the others to comment.
  7. Group 3: No problems for me there. R8R Gtrs converted me over from the La/Ac side to the Lu/Lr side last year. ;-)
  8. Metal-nonmetal line: I really like that idea. Double sharp (talk) 02:44, 21 July 2012 (UTC)
Quick feedback on all but 1,4 and 6 (pending more time).
2. Lanthanides/Rare earth metals: Not many more people other than chemists etc know what these are whereas 'Rare earths' are in the popular press regularly. The lanthanide title is still showing on the table right over the actinides title, albeit they do not have a colour box. Ten years ago I might've wondered about the basis for using 'rare earths' as category (I might've even said 'WTF are rare earths?'). But these days the rare earths category is almost pervasive (thanks to China). As well, the notion of parallels can be misleading. The light actinides behave more like transition metals. This is a weak argument given we say naught about the differences beween first row transition metals, and second/third row transition metals but I've thrown it into the mix for what it's worth.
3. Poor metals: Sweet.
5. Group 12: Jensen demolished the claims that Hg (in any meaningful sense) was a transition metal. I have however updated Cn to transition metal/poor metal status in light of your feedback.
7. Group 3: Beaut. I note Scerri supports this one too.
8. Metal-nonmetal line. Still not decided myself which means that, for now, I'll leave at as is/go with consensus. Sandbh (talk) 12:45, 22 July 2012 (UTC)

Leave as is with halogens out. I don't want a big debate (already developed). Will try to say once and never revise the words.

  • Don't group alkali and alkaline earth metals together. There is no widespread term for them all together. Pre-transition won't work. The mention on this page is the first time I've ever seen it. We'll hurt none by not combining them.
  • Don't stripe the cells. Bad looks, unclarity. We're doing fine now (have been so long). Messes in heads. Please don't. There are ways out. They do exist.
  • group 11 is by no means a poor-metal group (and again, destripe). If even there is basis, none (almost) recognizes it so.
  • group 12...First of all, Jensen is one point of view. Not everyone agrees with him (synthesizers, reprinters, publishers). As I know, half the world finds the three transition, half not. I like the transition side, without claiming it is the right one. Pick your favorite. Think you add a d electron even with them no more reacting, it is the end of the transition and not a part of new series. And visual beauty. The only thing I ask of here: Please no stripes! BTW, copernicium hasn't been shown to be transition metal. Only a metal. (for your thoughts only, future-element chemistry is almost certian for it). By no means the stripes are suitable. (As you see, I'm really against the stripes).
  • Astatine seems a metalloid to me (well-established cationic chemistry, no more words).
  • halogens are not worth a color. Wait, alkaline earth are abut not halogens, you say? Yeah. Going down the table all the periods you can catch, they are still metals. Are halogens nonmetals? The what about At? Why you all think 117 will be one? There are chalcogens also, pnictogens. Halogens are just further right (no metal problem for the first four). Thus always thought as nonmetals, for some beginners even by definition. They're not. Of course many people show periodic trends on them. But because the four are nonmetals (astatine is typically out, you noticed? The reason may differ by the author, but the point is the fact is influenced by the four. Without astatine) And because you add 1 electron, easier it is. Not 2 for oxygen-sulfur-etc. You maybe noticed that the same works for alkali metals.
  • Don't use yellow. More eye-catching than any other. More than our red. Or any. Any. Don't. Especially terrible between calm yet bright green and blue. Even the mild yellow makes the thing look like a peacock. In other places can bad better. Sure not good, though.
  • Aluminum is pretty poor.
  • Lawrencium is no poor. By the same logic is uranium a transiition element and not a actinoid. Chemistry shows the same. Eka-lutetium. Never seen literature than doesn't agree.
  • Against thr rare earths. Even if the Chinese mine me as crazy (do they have their Stakhanovs?), the elements are still known as lanthanioids for most chemists (unless you are an old-school Soviet one). Rare earth is more a geologist term nowadays. If even it conquers the world, we may lose a good analogy. And we have to stripe to be correct. Why not then striping lutetium as both lanthanioid and a TM? No excitement. And no win.

Also, a funny thing that one of Berkeley reports I've seen uses our current scheme. We'll run them outdated if anything changes :-)--R8R Gtrs (talk) 14:17, 22 July 2012 (UTC)

  • Some more comments based on R8R Gtrs':
    • I'm on the Group-12-as-transition-metal side. If I considered group 12 as not being TMs, then I would agree with Jensen on Hg, but I prefer thinking of group 12 as a transition metal group, for reasons R8R Gtrs has already explained. Besides, not everyone agrees with Jensen, and the inclusion of group 12 into the transition metals is a matter of much debate.
    • I really dislike the OR-ish "pre-transition metal" and "core nonmetal". Even if they've been used before, they are not terms even the average chemist (not to mention the average reader) will know of.
    • I've never seen the group 11 elements not included into the transition metals. While they (like the group 12 elements) have filled d-subshells, the d-electrons do react (unlike the group 12 elements, which bury their d-electrons and treat them as inner electrons almost all the time, with for the exception of HgF4) and they behave like transition metals. Jensen includes them into the transition metals.
    • I don't like the striping of the cells. I did mention the German one with striping, but that was only to get feedback. I don't like it myself – it's ugly. The diagonal line running through the cell just makes it worse IMHO (as someone else has said above, it could mislead people into thinking that there is a diagonal relationship running through the cell).
    • I agree that astatine is certainly a metalloid. Looking at that, we probably have to get rid of the halogens category. I agree with R8R Gtrs that the line of bright yellow between the soft green and blue colours for the nonmetals and noble gases is jarring and breaks the colour trend. Even the bright red we use for the alkali metals conforms to the general colour trend; the bright yellow we use for the halogens doesn't. Anyway, At is not really a halogen if you call it a metalloid (the term halogen refers to a nonmetal in group 17), and since At is a metalloid the prospects for halogen-like chemistry for 117 look rather bleak. The Uus article itself says that the −1 oxidation state is predicted to be the least stable of the four (−1, +1, +3, +5).
    • Even Jensen says that Lr isn't a poor metal, calling it just another of those Madelung rule exceptions that permeate the d- and f-blocks. Besides, it displays actinide-like and lutetium-like chemistry, and certainly not thallium-like chemistry (which would bolster the argument for calling it a poor metal).
    • I agree with R8R Gtrs that Al is a rather poor metal. (Anything to avoid the stripes. Besides, once you eliminate "pre-transition metal" you are no longer able to call Al anything other than a poor metal.)
    • Let's not use the "rare earths" category. Most chemists use "lanthanides" anyway. Certainly, the light actinides behave like transition metals. The lighter alkaline earth metals (Be and Mg) also behave like group 12 elements. Double sharp (talk) 10:36, 23 July 2012 (UTC)

Checkpoint summary

This is where we are up to, as I see it:

Poor metals (= p-block metals)
Group 3 membership (Sc, Y, Lu, Lr)
More evidence required as to category (no hurry; present if/when ready)
Worth further arguments or consideration (IMO)
Group 12
Location of metal-nonmetal line in the category legend
Quibbles: probably not worth revisiting right now
Lanthanides v rare earths
Group 11
Pre-transition metals
Colour scheme
Agree, but how to implement?
At is a metalloid but if we show this what do we call the remaining nonmetals between the metalloids and the noble gases?
  • We could show hydrogen as its own category and the remaining nonmetals as 'typical nonmetals'. So there would be four colour-coded categories of nonmetals:
Typical nonmetals
Noble gases
Justification: 1. hydrogen is often given its own chapter (e.g. Cotton & Wilkinson; Greenwood & Earnshaw); 2. 'typical nonmetals' seems to be the most common term for the other nonmetals. Sandbh (talk) 13:58, 25 July 2012 (UTC)
Disagree (ignore or continue the debate; you choose)
Use of mixed category elements
Elimination of halogen category

What do others say? Sandbh (talk) 13:12, 24 July 2012 (UTC)

Since we're discussing the entire presentation of the whole periodic table(!!!) on Wikipedia, we really ought to get everyone in the project informed so you'll have more feedback than just me and R8R. Double sharp (talk) 14:39, 25 July 2012 (UTC)
I did not follow this discussion in detail, but I am completely opposed to have one element stand out by its own color. Nergaal (talk) 15:58, 25 July 2012 (UTC)
Nergaal, if that element has its own category in this, it should have its own legend color in this. Periodic table elements are edited from the wikipedia stone age. You were in this wp:elem project earlier that I was. What did I or you not get? -DePiep (talk) 21:21, 27 July 2012 (UTC)
I think what Nergaal means is that there should not be legend colours used by only one element (in this case, H). Double sharp (talk) 06:21, 18 August 2012 (UTC)
Yeah, it makes H stand out too much. R8R Gtrs already doesn't like the "peacock-y" even "mild yellow" colour for the halogens, and would probably strongly oppose making a single element (even more so than a single group) stand out with its own article. (BTW, what colour could we use for it? Apart from yellow, nearly everything has been used.) Also, we don't need too many colours. Already we have problems due to an overuse of reds.
"Typical nonmetals" seems fine iff it's widely used.
The most important things to talk about IMHO are probably group 12, the metalloid line, and the proposed elimination of the halogen category. Group 3 and poor/post-transition metals could be talked about with those who made the change several years ago. I really dislike the mixed-category diagonally-divided cells, and so does R8R Gtrs; what do others have to say on that matter? Double sharp (talk) 12:19, 26 July 2012 (UTC)
I added an announcement on the noticeboard regarding this. Double sharp (talk) 05:04, 29 July 2012 (UTC)

A simple upgrade would be to:
(1) change 'post-transition metals' to 'poor metals';
(2) change the colour coding of astatine to that of a metalloid;
(3) change the 'halogen' category to a 'highly active nonmetals' category;
(4) change the colour coding of nitrogen and oxygen to that of highly active nonmetals (in light of their high Pauling electronegativity values); and
(5) change the 'other nonmetals' category to 'moderately active nonmetals'.

Such an upgrade would:

  • fix Al and At;
  • retain the spirit and colour of the halogen category;
  • be consistent with the descriptive theme of the 'noble gases' category (i.e. noble = not very active);
  • retain the 'metalloids' category like it is now, as a discrete top-tier category alongside metals and nonmetals; and
  • not require any mixed category elements :)

I think an argument could be made that iodine is not quite in the same league as the other active nonmetals when it comes to EN and, for example, oxidizing power, but would be happy enough for now with the highly active nonmetals being shown as N, O and the remaining (nonmetal) halogens. Sandbh (talk) 08:30, 30 July 2012 (UTC)

But nobody (well, except you) seems to call them "highly active nonmetals" and "moderately active nonmetals". Double sharp (talk) 08:58, 30 July 2012 (UTC)
Hmm. I get 7,969 hits googling the web for "active nonmetals" and 604 on Google Books. The search results go along the lines of:
  • "…fluorine, chlorine, bromine, and iodine are active nonmetals…";
  • "The most active nonmetals are found in the upper right corner of the periodic table (excluding the noble gases)"
  • "…across each period there is a gradual transition from an active (alkali) metal through less active metals and nonmetals to highly active nonmetals (halogen)…"
  • "The elements change from active metals to less active metals, to metalloids, to moderately active nonmetals, to very active nonmetals…".
If I search instead for "reactive nonmetals" I get 16,700 web hits and another 352 via Google Books.
I wouldn't mind if the two categories got called e.g. (a) less active, and active nonmetals, or (b) moderately actively and highly active nonmetals, or (c) moderately active and very active nonmetals, or some other combination. I like 'active' better than 'reactive', as active is a more encompassing term. Sandbh (talk) 12:57, 30 July 2012 (UTC)
Interesting. It's always nice to learn something new. But I think we should use the most commonly accepted and understood terms in the legend. Otherwise, we'll have to explain exactly what "active" refers to here every time we include a periodic table on an article. We can use this terminology in the main articles, like mentioning in the halogen article that they are all (well, except At) very active nonmetals, and so are N and O. Double sharp (talk) 06:37, 4 August 2012 (UTC)

Time to deprecate 'other nonmetals'

Double sharp, thank you. I've been thinking about this for a while and was just about to post something when I saw your comments, just above. DePiep was right when he said, "I know it [element categorization] is old & tough, but isn't solving that what we are here for?." I'll post what I was going to say and then respond to your comments.

Here's a table showing the proposed element categories:


The colour scheme is the standard one. The halogens aren't shown with a separate colour, on account of the (very good) reason given by R8R Gtrs.

The distinction between highly active and moderately active nonmetals follows that of Wulfsberg (1987, pp. 159–161). He groups the nonmetals into two categories, based on their electronegativity value. Nonmetals having an electronegativity of > 2.8 he calls very electronegative nonmetals (= N, O, F, Cl, Br); the rest, including iodine, he calls electronegative nonmetals. I've used 'active' instead of 'electronegative' as the main adjective, in order to be consistent with the categorization of noble gases as 'noble' or 'inactive' nonmetals.

In chemistry terms, the two categories of highly active and moderately active nonmetals are congruent with HSAB theory: highly active nonmetals are hard or borderline bases; the remaining moderately active nonmetals (including H and I) are soft bases.

Response to your comments (Rant warning: not aimed at you, just a general one). The term 'Other nonmetals' is "malarky". It means nothing. It's a "garbage can" term, for the leftovers, when nothing better comes to mind. It has almost zero information content. The first time I saw 'Other nonmetals' was in Wikipedia. Having not seen the term before, I remember thinking WTF are other nonmetals? Metalloids: check! Halogens: check! Noble gases: check! But WTF are other nonmetals? Sure, I knew the individual elements but had no idea what the common thread was that caused them to be called other nonmetals. The 'other' in 'other metals' conveyed no sense of meaning. OTOH, the meaning of highly/moderately active nonmetals would be significantly more familiar to most readers, including chemistry, science, and related professionals (IMO). Whereas there is (almost) no chemistry behind 'other metals', no immediately obvious sense of meaning, and no value or information add. It's an awful term that we should seek to consign to the dustbin of history, given the existence of much better terminology, in terms of (1) precedent in the literature; (2) grounding in chemistry; (3) meaning; (4) value add; and (5) internal consistency (per R8R Gtrs' insightful observation). That concludes today's rant.

Wulfsberg G 1987, Principles of descriptive inorganic chemistry, Brooks/Cole, Monterey CA, ISBN 0-534-07494-4

Sandbh (talk) 15:00, 4 August 2012 (UTC)

The current one is not bad – I like it. And yes, anything to get rid of the "other nonmetals" grouping. (It's obvious what it means, but it doesn't make much chemical sense.) (I was thinking of "typical nonmetals" when I made that comment, BTW.)
I have a feeling people will come and make noise with Lu/Lr being shaded as transition metals, BTW. They're also lanthanides. And they might even argue that shading them as lanthanides while not putting them together with the lanthanides is confusing(!!). We'll see what they think of this Lu/Lr shading; I'm on your side.
Shouldn't we alert all the members of WP:ELEM, BTW? The announcement doesn't seem to be working. The only responses you've got so far are from me and R8R, and that's hardly a consensus (3 people only!). Double sharp (talk) 06:29, 5 August 2012 (UTC)
And BTW, "volatile metals"? Could you please tell us where you found that term? It sounds like an interesting addition to the Group 12 element article. (And who used "coinage metals" for group 11?) Double sharp (talk) 06:34, 5 August 2012 (UTC)
Five citations re Group 12 volatile metals:
1. '…the volatile metals, arsenic, antimony, zinc, cadmium, and mercury, are inverted into oxides when heated in air or oxygen' (Fownes 1869, p. 279).
2. 'Still further to the right the coinage metals (Cu, Ag, and Au) and volatile metals (Zn, Cd and Hg) show strong vertical relationships' (Simmons 1947, p. 589).
3. '…zinc, cadmium and mercury…are unusually low melting and volatile' (Massey 2000, p. 159).
4. 'Because zinc, cadmium, and mercury…have comparatively low boiling points, 907°, 768°, and 357°, respectively; they are referred to frequently as the volatile metals' (Beringer 2005, p. 368).
5. In New Scientist 21 April 2012, there is an article (p. 12) called 'A factory for elements that barely exist', by Kat Austen. In part, the article notes that, ' more volatile than its homologue mercury, and is the only metal known to be a gas at room temperature'. Apparently this is a 'deduction' based on how far atoms of 112 travelled across a gold surface, so saying 'known' is hyperbole. An engaging conclusion, in any event.
Beringer P 2005, Remington: The science and practice of pharmacy, 21st ed., Lippincott, Williams & Wilkins, Baltimore
Fownes G 1869, A manual of elementary chemistry, Henry C Lea, Philadelphia
Massey AG 2000, Main group chemistry, 2nd ed., John Wiley, Chichester
Simmons PA 1947, 'A modification of the periodic table', vol. 24, no. 12, Journal of Chemical Education, Dec, pp. 588–591
Sandbh (talk) 12:04, 6 August 2012 (UTC)

So, after over a month of discussion, shouldn't we ask the members who haven't participated in this discussion what they think the outcome should be, similarly to what happened with our vote for a flagship article (which was decided to be hydrogen)? Double sharp (talk) 12:49, 28 August 2012 (UTC)

Yeah, go 'head. Think of inviting Wp:CHEMS and Wp:SCIENCE members, also--R8R Gtrs (talk) 20:26, 4 September 2012 (UTC)
P.S.I don't want to get in deep, but I'd not call nitrogen active...trying heating it with iron and then with "non-active" sulfur, and see which of the two reactions does occur
I am neutral on the other proposals, but I don't agree with splitting into the current green and yellow (very OR). If we get rid of halogens, then just merge them with with the other nonmetals. Also, instead of reactive electronegativity could be used, but that would be still OR-ish. Nergaal (talk) 00:51, 5 September 2012 (UTC)
Has anyone thought of giving hydrogen its own category? Just throwing this out there. StringTheory11 (tc) 00:55, 5 September 2012 (UTC)
That was discussed in the previous section, but Nergaal and I are against it, because it makes hydrogen stand out too much. (R8R already finds the yellow of the halogens too "peacock"-y, so I don't think he'd like that suggestion either.) And after, H is a nonmetal.
We should change "other nonmetals" to a different name (non-OR, of course), though. "Typical nonmetals" was suggested, and seems fairly common. Double sharp (talk) 03:58, 5 September 2012 (UTC)

My proposal (close to R8R's):

(BTW, don't delete Template:Element color/Halogens after it becomes unused. That would break almost every old revision of a periodic table.)

Of course, H is not really a typical nonmetal. But then, what do we do with it?

(P.S. Cn is actually only known to be a metal, and not a transition metal, as R8R Gtrs states. However, we can't really use any other colouring than "transition metal".) Double sharp (talk) 05:43, 5 September 2012 (UTC)

I reread this section Time to deprecate 'other nonmetals'. (Organisational note: I'll respond to that topic, so Group 12 is not involved; the discussion started earlier in to main thread section #Eight category table. Really, discussing multiple independent topics in one thread is not helpfull). This is what I found:
- Sandbh and R8R propose: regroup & rename into "highly active nonmetals", "moderately active nonmetals" (or such names; based on electronegativity), no category named Halogen (as a group it stays though). Source: Wulfsberg G 1987.
- Double sharp proposes "other nonmetals" (currently used).
- Other suggestions ("core nonmetals", HSAB-based, ...) look less substantial to me.
My points:
1. Although "other nonmetals" is not used widely outside of wp, if we need a description of that category we are perfectly free to do so. Maybe the capital should go as it is not a proper name, but a description we can provide, especially with a wikilink. I can also note that in the Venn-diagram of category names and descriptions it serves a completifying task (see row 3 & 4 in the basic legend: a complete, mutually exclusive set of category names and their colors).
2. That said, I cannot be convinced by some of Doublesharp's arguments: [1] (that's where legends & wikilinks are invented for); [2] ("I like"), and other argumentation. I admit all your intuition in this (most other editor's here) is far better than mine, but if one cannot argument or describe the base, it is more like OR or personal preference.
3. Editors seem to have unarticulated opposition (uncertainity? fear?) to removing Halogens from the list of categories. While really, that is a consequence of mixing up topics. Halogens is and will stay a group. As a category, if the logic, properties and sources require to split the set up: then it be so. Already now I count some six groups that are not homogeneous wrt category. No problem.
4. I support the proposal using "highly active nonmetals", "moderately active nonmetals" (Sandbh & R8R), because it is based on a source, has a straight scientific base in electronegativity, and has a small undecided grey area (an area that takes up so much space on this page). It implies we drop the Halogens category here.
5. Consequences would be: check and maybe split Halogen page, review legend colors &names. All this can follow a tough logic on category classification. -DePiep (talk) 10:11, 5 September 2012 (UTC)
Hmm. In this thread, what I see is:
  • Sandbh proposes the one in the image.
  • I propose "typical nonmetals", with halogens merged into typical nonmetals.
  • The way I see it, R8R was actually referring to my comment when he said "go 'head", and did raise a point that the "moderately active" and "highly active" is quite debatable (Fe will react with S, but not with N).
  • Nergaal supports merging the halogens into the other nonmetals, and opposes the highly active/moderately active division because it is "very OR" (I agree; the source is talking about EN values, not reactivity) and is quite debatable (R8R raised the case of N not being that reactive, and yet having a high EN.)
  • ST11 proposes giving H its own category (which would solve the problem with my and Nergaal's proposal where H is not a very typical nonmetal), but Nergaal and I had previously (see the previous subsection) opposed this because it would make H stand out too much. Double sharp (talk) 10:30, 5 September 2012 (UTC)

how about reactive non-metals (i.e. not inert) instead of typical? Nergaal (talk) 14:28, 5 September 2012 (UTC)

==== random break ====
Hey, don't make me look silly. I responded to a subsection (level 4) created by Nergaal. -DePiep (talk) 23:07, 9 September 2012 (UTC)


Probably because nitrogen is nearly inert at room temperature; even hydrogen is "comparatively unreactive at room temperature…" (Greenwood & Earnshaw 1998, p. 43) Sandbh (talk) 14:18, 8 September 2012 (UTC)
also, I would be fine with merging group 1 & 2 into s-block metals, and Ln and An into f-block metals, or just inner-trans metals. Nergaal (talk) 14:30, 5 September 2012 (UTC)
Why two unrelated proposals in one subsection, why a new subsection (level 4) when you are adressing a running conversation in the previous (level 3), and why I would be fine with as an argument? How is the titleword random helpfull? -DePiep (talk) 14:41, 5 September 2012 (UTC)
 end of ==== random break ====

Yes, I'm not really not in favor of cutting nonmetals in two (did offer invitations instead). I think the usage of the term shown is more like that of a useful phrase than a strict scientific term (doubt it that there are established definitions of "moderately active nonmetals"), this configuration's also tricky.--R8R Gtrs (talk) 14:56, 5 September 2012 (UTC)

DePiep has hit the nail on the head with his point (3) above. I, too, shared the 'unarticulated opposition' — I might even say 'visceral reaction' — to eliminating Halogens, but it really is as he says, confusing Category with Group. Perhaps the solution, at least as far as the template goes, is to add emphasis for the groups. R8R Gtrs listed most of the groups in his picture [#Time to deprecate 'other nonmetals'|above]], but I think we could do even better. Maybe a complete list of group numbers and names at the bottom, including the groups named after their first element, and each one is hyperlinked to the wp article about the group. And, if someone can figure out the wikimarkup magic, have the group column and its number/name highlighted when the cursor hovers over it. Something like this would serve to accentuate the groups including halogens and so reduce opposition to eliminating halogens as a category. YBG (talk) 05:49, 8 September 2012 (UTC)
That was Sandbh's picture, actually. Double sharp (talk) 07:00, 8 September 2012 (UTC)
So? -DePiep (talk) 00:00, 9 September 2012 (UTC)

────────────────────────────────────────────────────────────────────────────────────────────────────This came to my mind: can we call that category "unspecified nonmetals" (halogens and noble gases being the specified ones of course)? In standalone use, outside of the categories, the wording "other nonmetals" is awkward indeed. The reader thinks he or she is missing something (correctly). -DePiep (talk) 18:59, 25 November 2012 (UTC)

Hydrogen (and categories v groups)

Sorting out hydrogen is the key, as I see it. StringTheory11 was on the mark with his suggestion along the lines of showing hydrogen in its own non-metal sub-category. As per DePiep's approach, there is strong support for such a treatment in the literature. For example: "The chemistry of hydrogen is so unique that this element is in reality in a class by itself" (McCoy & Terry 1920, p. 562); "The chemistry of hydrogen bears little resemblance to that of any other element…" (Emsley 1971, p. 20); "Hence the chemistry of hydrogen is the only chemistry of its kind, as it were, the chemistry of an elementary particle, the proton." (Trifonov & Vlasov 1987, p. 24). Nergaal: unless I've missed something your opposition to this proposal, on the basis that hydrogen would then stand out too much, appears to lack a strong scientific basis.

If hydrogen is recognized as a nonmetal in its own subcategory, the rest of the categorization puzzle more or less falls into a better place. Major categories would be Metals, Nonmetals, and Unknown chemical properties. Subcategories would be (current) alkali metals through transition metals, plus poor metals; then metalloids, hydrogen, typical nonmetals, and noble gases. Having thought about this some more I'd also recommend that the shared borderline between the metals category box and the nonmetals category box be positioned over the middle of the metalloid subcategory box (in the same manner as is shown in the eight category table), rather than the current practice of showing metalloids as a major category.

YBG, re your vision of a periodic table showing both categories and groups: sign me up.

  • Emsley J 1971, The inorganic chemistry of the non-metals, Meuthen Educational, London
  • McCoy HN & Terry EM 1920, Introduction to general chemistry, McGraw-Hill, New York
  • Trifonov DN & Vlasov LG 1987, Silhouettes of chemistry, Mir Publishers, Moscow

Sandbh (talk) 14:18, 8 September 2012 (UTC)

Here's a compact periodic table using Sandbh's latest proposal (just above):

I've deliberately used a soft colour here for H, so that it doesn't stand out too much, but this colour is in no way finalized and is open to suggestions. Double sharp (talk) 14:56, 8 September 2012 (UTC)

Thank you Double sharp. I've edited the table by moving the hydrogen sub-category box from being in front of the alkali metal sub-category box to being in-between the metalloid and typical nonmetal sub-category boxes. On the question of color, and as a personal preference, I believe there ought to be room for some yellow somewhere, not necessarily for H. Sandbh (talk) 23:32, 8 September 2012 (UTC)
Maybe replace the poor metals color with yellow? Gray is never a good color to use for something known. StringTheory11 (tc) 00:00, 9 September 2012 (UTC)
Again and again I say: use a straight scientific criterium, and then stick with that. Afterwards, we can do colors & borders & descriptions. -DePiep (talk) 00:10, 9 September 2012 (UTC)
How is hydrogen more special then helium? Helium has the highest electronegativity, is the least reactive, is the only element that is fine with 2 electrons in the electron shell (H is typicall happy with 0) and so on? Why aren't we emphasizing carbon also? Is the only element that can form long chans of single bonds that are stable under noral conditions? why not lead since it is the heaviest stable element? I can give many other examples why a lot of elements are unique. the point of the periodic table is to be informative, not to give a color to each element. Nergaal (talk) 00:47, 9 September 2012 (UTC)
I'm a little bit confused about "typical nonmetals." I perfectly remember that my teacher back in school told me fluorine was the only typical nonmetal, since she named the ability to form positive OS a metal-like property and fluorine is the only one not to. The opponents say "other" is a bad category. I'd rather say so not. It's a very easily understood term. It is very general. You may not understand what "transition" about the pink cells is, but "other" is clearly gettable. Plus we could have minus a color by getting this (in my opinion, a very good) category. It is not a term for scientists... But we are specializing mainly on the casual people, right? I'm referring to the fact that "typical" may puzzle a non-chemist.--R8R Gtrs (talk) 17:50, 10 September 2012 (UTC)
I suppose "typical" can mean different things to different people. But then, so does "transition" (group 12, and to a much lesser extent 3 and 11 some time ago.)
I understand your rationale, R8R. But "other metals" doesn't provide that much information for a reader. At least with a name like "transition metal", even if what the transition is is not obvious, at least the reader knows that there is some sort of transition. With generic nondescript names like "other metals", though, the reader doesn't get this information, and won't understand how exactly these elements are similar to each other. Double sharp (talk) 10:55, 11 September 2012 (UTC)
By analogy to "poor metals", why not "ignoble non-metals" or "peasant non-metals"?  :) YBG (talk) 06:58, 11 September 2012 (UTC)
LOL. But I don't think any researcher has used such terms, except perhaps in jest! :-) Double sharp (talk) 10:55, 11 September 2012 (UTC)
"Ignoble" would be a good antonym of "noble", though. For example, "Caesium is the most ignoble metal..." Double sharp (talk) 12:27, 14 September 2012 (UTC)

Hydrogen is more special than other elements because its chemical behavior is distinctly odd—much more so than any other element. Two results then come to mind. The first is that hydrogen doesn't have any nonmetal or metal peers (unlike helium -> noble gases; carbon -> typical nonmetals; and lead -> poor metals). The second is that hydrogen doesn't map well to any periodic table group—witness over 100 years of arguments as to which group hydrogen should belong to (including e.g. 1, 14, 17, no group, its own group or multiple groups), and Mellor's description of hydrogen as a 'rogue' element.
In terms of its chemical behavior, hydrogen:

  • is a good reducing agent
  • is liberated at the cathode during electrolysis
  • is displaced by more active metals from dilute acids or water
  • forms its most stable compounds with non-metals
  • forms a solvated cation in aqueous solution
  • is capable of forming alloys (solid solutions) with metals.

This is very strange behavior for a nonmetal. Even when behaving more conventionally as a non-metal, in the form of a hydride ion, the resulting compounds are intrinsically unstable since the hydrogen atom, with its single proton, is unable to sufficiently control two valence electrons.
Hydrogen doesn't satisfy any descriptive criterion or set of criteria attempting to define a metal that I'm aware of. It's clearly a non-metal in that sense. But neither is its chemistry—which is the chemistry of the proton rather than the chemistry of an element—typical (so to speak) of typical non-metals. Sandbh (talk) 11:58, 11 September 2012 (UTC)

OK, let's go on thinking hydrogen is quite different than the other nonmetals. I think the current "other nonmetals" punchline works; why would separate them? Let's color Alaska or Hawaii differently than the rest of U.S. There are differences in climat, population, lots of stuff. But these are still U.S.! (I know it's kinda poor an analogy, it's to make an impression, not to serve as a point)
When did I say I like "other metals"? No, I love poor more. It's an established term with more-or-less fixed borders.
(citation: "But "other metals" doesn't provide that much information for a reader. At least with a name like "transition metal", even if what the transition is is not obvious, at least the reader knows that there is some sort of transition. With generic nondescript names like "other metals", though, the reader doesn't get this information, and won't understand how exactly these elements are similar to each other.") Huh! Like your point about the transition. Good. But think it should be used slightly differently. I see your point about not getting the info. Yet I think that if it doesn't work, "typical" won't work either, cause, well, it's not that common. If you understand it, than you would also understand the point of "other," as well. I even heard concerns that phosphorus and selenium are not typical nonmetals in Wiki quite lately (don't recall the context and exact phrasing). What I'm getting at is, it's not that necessary to separate other nonmetals and the lonely hydrogen. Because there is a common criterion to include them all together (nonmetallicity or whatever the word is). Want the thing to be as basic as it keeps sence. Also, why is H chemistry called chemistry of a particle? There are also deuterium, tritium, that are almost identical on chemistry (a couple of degrees diff in water mp and the Iike.) If it is related to abundance, then it's not strictly scientific, more a figure of speech.
What do we gain by separating hydrogen? I'm pointing at the non-chem audience again. There are more people who would not clearly get the point than those who would. Don't fix it if it ain't broke.
Sorry, feel sick, so not sure if I'm understandable, hope you get my points--R8R Gtrs (talk) 19:39, 12 September 2012 (UTC)
  • R8R Gtrs, I don't understand your points. The term 'other nonmetals' is bad, unhelpful, lazy science. It says (almost) nothing about the nature of these elements. On the other hand, calling them 'typical nonmetals' says that that is just what they are–'typical' for their kind. So, if you want to learn about nonmetals, start with these as the most typical examples of nonmetals. Even non-chemists would be able to work that out.
  • If you think non-chemists won't be able to work out what 'typical nonmetals' means, fair enough–we will have to disagree on that point. Your assertion that if someone understood 'typical nonmetals' then they would also understand 'other nonmetals' makes no sense to me.
  • The subcategory of typical nonmetals still shows some variability in degrees of nonmetallic character. As you note, fluorine is probably the most non-metallic of the typical nonmetals. Whereas phosphorous and selenium are neighbors of the metalloids so they show some metalloid-like attributes. But they are not quite metalloids and can still (mostly) be accommodated within the typical nonmetals subcategory.
  • H chemistry is called the chemistry of the proton since, once H loses its single valence electron it doesn't have an inner electron screening its nucleus, unlike all other elements. Sandbh (talk) 11:27, 14 September 2012 (UTC)
I dunno. I feel I got nothing left, so every point I can think of has been said already. You're good, I like your points, it's starting to get me... Yet I don't feel like it. Really dunno. I may explain what I meant when writing those. I think that-- well, no agree, but at least you do understand why I am in favor of that one, right?-- the "other" is easy to get. And typical needs more knowlegde to get it. No description, okay. I just realized why you protect your points. I still think the less categories as it keeps sense, the better (colors go before names, IMO, even though that's the point you disagree with, right?). You go 'head and disagree. That's awesome, since you back up yourself with citations and keep head cool. And I, in contrast, have mentioned no source really, and now got nothing left. I'll be now more okay with your scheme. Thanks for explaining it over to make me understand your points (will try to go unblinded more now)
(About particle chem) Still, H doesn't completely lose the electron (always covalent bonding), so some screening still remains. Naked proton is still unknown in chemistry, huh?--R8R Gtrs (talk) 19:21, 14 September 2012 (UTC)
Yep, no sight of a naked proton, as far as I know Sandbh (talk) 12:31, 30 September 2012 (UTC)
@R8R: Whether you colour Alaska and Hawaii differently from the rest of the U.S. or not depends on what you are trying to emphasize, doesn't it? You would do that if you were emphasizing climate or population, as you say, but not if you were emphasizing current political boundaries. We've decided to classify the elements chemically. We could just as well have classified them by blocks. Chemically, H stands out quite noticeably from the other nonmetals. Double sharp (talk) 12:27, 14 September 2012 (UTC)
Stands out... I may be fine with separating on the grounds of getting a more meaningful name, but that one is still not for me (worked years fine, and without that main reason it seems no good. I think that nonmetals are a label, like countries to some extent are (like that triangle in the north of Sudan, or jungle borders in Central Africa, sometimes controled by no state, just worldwide recognized claims exist, but no real control. There are still uncontacted people no state can control. Hydrogen is recognized as a nonmetal (no opposition), can go under the same title and color (so like the map analogy (was no argument, just analogy to make easier to understand), do you get it now?). Like those Central African jungleforests. You maybe remember I like fever colors as it keep having sense. Do as you like, though. Got nothing more to say--R8R Gtrs (talk) 19:15, 14 September 2012 (UTC)
It seems to me that the problem here is that "Other nonmetal" and "Typical nonmetal" makes is sound like there is a specific group named "Other" or "Typical", which there is not. So that led me to think that maybe the thing to do was to set up the grid so that it was intuitive that "Other" was NOT the name of a group, but simply a label that meant "none-of-the-above". It would be a whole lot easier if it could come after (i.e., to the right) of the groups with specific names, but that rather spoils the left-to-right correlation with the order of appearance in the Periodic Table. Anyway, the wikimarkup is lousy, but maybe this would get the creative juices flowing and help us find a way forward. YBG (talk) 03:41, 15 September 2012
Metal groups Metaloid

Nonmetal Unknown
Alkali earth
"Other nonmetals" is probably not used as a group name, but "Typical nonmetals" seems to be used that way. So I don't think there is a problem if we changed to using "typical nonmetals". (Of course, we'll need to sort out hydrogen, as its properties are definitely atypical for a nonmetal.) Double sharp (talk) 05:50, 15 September 2012 (UTC)

Reactive nonmetals and noble gases

Nergaal was right when he said, 'how about reactive non-metals (i.e. not inert) instead of typical? Nergaal (talk) 14:28, 5 September 2012 (UTC)'. Sure, hydrogen is comparatively unreactive at room temperature and nitrogen is nearly inert but both are way more reactive elements—in general—than the noble gases, as are the rest of the non-noble nonmetals. Using reactive nonmetals instead of typical nonmetals makes the hydrogen problem go away. And whereas I can't find much specific usage in the literature of other nonmetals there are many more mentions I can find of reactive nonmetals or variations thereof (e.g. less reactive, reactive, more reactive, highly reactive, most reactive etc). So, it's a big metalloid vote from me to replace other nonmetals with reactive nonmetals.
The only question then remaining would be whether to distinguish between highly reactive nonmetals (O?, F, Cl, Br?) and the rest of the (merely) reactive nonmetals. The halogens may not have their own color anymore but there may still be some value in highlighting the highly reactive nonmetals, given this terminology is often associated with the elements in the vicinity of the top right hand corner of the periodic kingdom. Sandbh (talk) 23:00, 19 September 2012 (UTC)

Here are some quotes from the literature showing usage of the expression 'reactive nonmetals':
1. 'Fluorine and chlorine are the most active of the reactive non-metals, while nitrogen is the least active of this class.' (Biddle & Bush 1949, p. 181)
2. 'If the position of the Group 0 elements is excluded, the most reactive non-metals are found in the upper right-hand portion of the table.' (Murphy & Rousseau 1969, p. 81)
3. 'In each case, there is a left-to-right trend from very reactive metals to less reactive metals followed by less reactive nonmetals and on to quite reactive nonmetals, ending with an essentially unreactive, or inert, element. This pattern is referred to as periodic behaviour.' (James, Schreck & BeMiller 1980, p. 26)
4. 'Adjacent to the inert gases in the outlined portion of the diagram are sixteen elements that are reactive non-metals. The group includes solids such as carbon (C), phosphorus (P), and sulfur (S), as well as gaseous elements (H, N, O, F, CI).' (Leinfelder, Taylor & Morr 1982, p. 13)
5. '…nonmetals can be split into two groups, the 'noble' or inert gases and the reactive nonmetals.' (Long & Hentz 1986, p. 84)
6. 'By the end of 8th grade, students should know that…There are groups of elements that have similar properties, including highly reactive metals, less reactive metals, highly reactive nonmetals (such as chlorine, fluorine and oxygen) and some almost completely unreactive gases (such as helium and neon).' (AAAS 1994, p. 78)
7. 'From left to right across the periodic table, elements change from being reactive metals, through less reactive metals, metalloids, less reactive non-metals to reactive non-metals. (On the extreme right are the noble gases.)' (Hill & Holman 2000, p. 49)
8. 'Describe how groups of elements can be classified based on similar properties, including highly reactive metals, less reactive metals, highly reactive nonmetals, less reactive nonmetals, and some almost completely nonreactive gases.' (Padilla, Cyr & Miaoulis 2005, p. 27)
9. 'Nonmetallic elements span the range from extremely reactive fluorine to relatively unreactive elements such as carbon and nitrogen.' (House 2012, p. 393)
Sandbh (talk) 04:08, 22 September 2012 (UTC) Sandbh (talk) 08:50, 25 February 2013 (UTC)
  • American Association for the Advancement of Science 1994, Benchmarks for science literacy, Oxford University Press, New York
  • Biddle C & Bush GL 1949, Chemistry today, Rand McNally
  • Hill G & Holman J 2000, Chemistry in Context, 5th ed., Thomas Nelson & Sons, Cheltenham
  • House JE 2012, Inorganic chemistry, 2nd ed., Academic Press, Burlington MA
  • James ML, Schreck JO & BeMiller JN 1980, General, organic, and biological chemistry: chemistry for the living system, D. C. Heath, Lexington, Mass.
  • Leinfelder KF, Taylor DF & Morr DV 1982, Laboratory and clinical dental materials, 3rd ed., University of North Carolina Press, Chapel Hill
  • Long GG & Hentz FC 1986, Problem exercises for general chemistry, 3rd ed., John Wiley & Sons, New York
  • Murphy DB & Rousseau V 1969, Foundations of college chemistry, The Ronald Press Company, New York
  • Padilla MJ, Cyr M & Miaoulis I 2005, Prentice Hall Science Explorer (Indiana, Grade 6): Teacher's Edition, Prentice Hall, Upper Saddle River, NJ
Sure, I can see that the expression "reactive nonmetals" is used. But then, how do we decide what to put in it? The precise elements in that category seem to be somewhat debatable (Br? N? H?). Double sharp (talk) 04:18, 22 September 2012 (UTC)
Are you asking if there would be a basis to distinguish between highly reactive nonmetals v (merely) reactive nonmetals? If so, my first response would be to suggest that any nonmetal capable of reacting with a noble gas to form a simple compound ought to considered a highly reactive nonmetal. Without having looked into noble gas chemistry too much I suspect that such an initial criterion would apply only to oxygen and fluorine. Sandbh (talk) 03:22, 23 September 2012 (UTC)
Possibly chlorine would also count, because of XeCl2, but it's still uncertain whether it is really a true compound. So that criterion would give the list O, F, and possibly Cl. (But aren't there many possible criteria for distinguishing them? Then how do we decide which to use? You did use a different one in the previous table where N and Br were also added to this list, and R8R Gtrs pointed out that Fe reacts with S, but not with N.) Double sharp (talk) 05:15, 23 September 2012 (UTC)

(outdent) What about dividing nonmetals into (1) Hydrogen (2) Solid nonmetals and (3) noble gases? YBG (talk) 05:53, 23 September 2012 (UTC)

Except, bromine is a liquid.--Jasper Deng (talk) 06:02, 23 September 2012 (UTC)
Details, details, details. (Headslap) And non-gasseous non-metals is a bit too cumbersome, to say nothing about the clumsiness of defining the group by what it isn't. YBG (talk) 07:35, 23 September 2012 (UTC)
Besides, N, O, F and Cl are gases, but are certainly not noble gases. If we include them (and Br, the liquid nonmetal) into the "Solid nonmetals" category, that category has then become "Typical nonmetals". We shouldn't colour the entire cell based on state at STP – that's what the colouring of the atomic number is for. Double sharp (talk) 08:46, 24 September 2012 (UTC)
How could I have been so rediculous! I was trying to think outside the box, but apparently I slipped into some sort of an alternate reality. Many appologies for wasting your time. You guys deserve a barnstar for your polite responses to me!!!! Many thanks!!! YBG (talk) 14:31, 24 September 2012 (UTC)

Looking through the literature I find that O, F, Cl, Br are the only nonmetals that are more or less consistently referred to as being 'highly reactive', or the like. In contrast, I can't get a clear highly reactive bead on any of the rest of the nonmetals:

  • H is sometimes described as being very reactive in the presence of a catalyst or at elevated temperatures, and at other times is described as being relatively unreactive at room temperature.
  • 'In spite of a high bond strength hydrogen is moderately reactive, combining with most non-metals and the more electropositive metals directly to give hydrides.' (Shaw 1968, p. 8)
  • 'Dihydrogen is relatively inert, due its high bond energy. Its reactions usually require activation by heat or radiation energy, or the presence of a suitable catalyst.' (Eagleson 1994, p. 509)
  • ' comparatively unreactive at room temperature...At higher temperatures hydrogen reacts vigorously, even explosively, with many metals and non-metals to give the corresponding hydrides.' (Greenwood & Earnshaw 1998, p. 43)
  • C (as graphite) is 'chemically an inert element and reacts with other elements only at elevated temperatures or with some other from of energy input.' (Wiberg 2001, p. 792).
  • N: 'In general, nitrogen is very unreactive at normal temperatures…reactivity is significantly increased by raising the temperature.' (Wiberg 2001, p. 600).
    • Oxygen:
      • 'Breathing air has its drawbacks. Oxygen is a highly reactive molecule, producing molecules of peroxide (O22–) and superoxide (O2) after it reacts during respiration to produce water. These highly reactive forms of oxygen would damage the delicate biological structures within a cell. Consequently, most organisms that breathe air have evolved enzymes to deal with these dangers.' (Arber, Garner & Hasnain 1988, p. 50)
      • 'Considering the high reactivity of oxygen, its existence as free O2-gas in the atmosphere is possibly the result of constant new O2 production and addition. Withou replenishment by photosynthesis, our atmospheric oxygen may be consumed in about 3,000 years due to oxidation processes in the Earth's crust...' (Scharpenseel & Becker-Heineman 1990, p. 5)
  • P is sometimes described as being highly reactive (in the form of white P) until it is pointed out that black P, which is the most thermodynamically stable form of P, is almost inert.
  • S is occasionally described as being very reactive, and at other times as being, for example, almost inert in comparison to oxygen.
  • '...sulfur is displaced slowly from a hydrogen sulfide solution by iodine.' (Hogg & Bickel 1941, p. 426)
  • 'Sulfur should be a typical nonmetallic substance, but since the nonmetallic properties decrease as the atomic weight increases we should expect sulfur to be less active than oxygen. This decrease in chemical activity is so evident that we shall do well to contrast the activity of oxygen with the chemical inertia of sulfur.' (Hopkins & Bailar 1956, p. 258)
  • 'Elementary sulfur is quite reactive, even at ordinary temperatures, although generally less so than oxygen.' (Nebergall, Holtzclaw & Schmidt 1963, p. 347)
  • 'Sulfur is a very reactive element especially at slightly elevated temperatures (which presumably facilitates cleavage of S–S bonds). It unites directly with all elements except the noble gases, nitrogen, tellurium, iodine, iridium, platinum and gold, though even here compounds containing S bonded directly to N, Te, I, Ir, Pt and Au are known.' (Greenwood & Earnshaw 1998, p. 662)
  • 'Sulfur is not regarded as a particularly good oxidizing agent.' (Rogers 2011, p. 504)
  • Se: The Simple English Wikipedia describes Se as being 'not very reactive'.
  • I: Being a halogen, I is mostly described as being chemically very active. However the reactivity of iodine is sometimes qualified—explicitly or implicitly—when compared to that of the other halogens:
    • 'In its chemical properties iodine shows a general resemblance to the other halogens, although it is much less [italics added] active.' (Lowry & Cavell (1944, p. 297).
      • 'By analogy one would predict that iodine would react with water as do bromine and chlorine...This reaction does take place but the extent of the reaction is negligible since iodine is too insoluble and too unreactive...Iodine is too unreactive to displace most of those elements which are displaced by bromine and chlorine.' (Hogg & Bickel 1941, p. 426)
    • Sidgwick (1950) describes F as 'quite exceptionally reactive' (p. 1101); Cl as 'extremely reactive, although less so than F' (p. 1139); and Br as 'very reactive' (p. 1141). Tellingly (in my view) he has nothing to say about the reactivity of I.
    • 'Bromine is a fairly strong oxidizing agent' (Brown & Sallee 1963, p. 311); 'Iodine is a mild oxidizing agent…' (Munn 2000, p. 379); 'Fluorine, chlorine and bromine will all oxidize Fe2+ (aq) to Fe3+ (aq)…Iodine, however, is such a weak oxidizing agent [italics added] that it cannot remove electrons from iron(II) ions to form iron(III) ions.' (Hill & Holman 2000, p. 230). These observations speak to the relatively modest reactivity of iodine since, for a nonmetal, reactivity is usually gauged by its ability to serve as an oxidizing agent (Brady & Senese 2009).
    • In discussing halogenation, Eagleson (1994, p. 477) says that fluorination is often explosive whereas iodination is the most difficult form of halogenation due to 'the low reactivity of iodine' (Cl and Br effectively being in-between, and comparable in reactivity).
    • 'Chlorine is also very reactive, but iodine is only moderately reactive.' (Hill 1999, p. 220).
    • The relatively low reactivity of iodine means that HI, for example, dissociates at moderate temperatures into hydrogen and iodine (Wiberg 2000, p. 271). At higher temperatures even the more stable iodides show appreciable dissociation (Mills 1968, p. 296).

On the above basis, it seems to me that a reasonable argument can be made for distinguishing between three categories of nonmetals:

Reactive nonmetals (7): H, C, N, P, S, Se, I
Highly reactive nonmetals (4): O, F, Cl, Br
Noble gases (6): He, Ne, Ar. Kr, Xe, Rn

The benefits of such a taxonomy, as I see it, are: It gets rid of the execrable term 'Other nonmetals'. It eliminates any difficulties with hydrogen. It preserves the current three-fold categorization of the nonmetals: less reactive | more reactive | nonreactive. It is grounded in the literature. It doesn't disturb the current colour scheme. Sandbh (talk) 07:29, 29 September 2012 (UTC)

  • Arber J, Garner D & Hasnain S 1988, 'X-rays highlight metals in biology', New Scientist, 21 January, pp. 48–51
  • Brady JE & Senese F 1999, Chemistry: The study of matter and its changes, John Wiley & Sons, New York
  • Brown GH & Sallee EM 1963, Quantitative chemistry, Prentice-Hall, New York
  • Eagleson M 1994, Concise encyclopedia of chemistry, Walter de Gruyter, Berlin
  • Greenwood NN & Earnshaw A 2002, Chemistry of the elements, 2nd ed., Butterworth-Heinemann, Oxford
  • Hill G 1999, GCSE science, 2nd ed., Letts Educational, London
  • Hill G & Holman J 2000, Chemistry in context, 5th ed., Nelson Thornes, Cheltenham
  • Hogg JC & Bickel CL 1941, Elementary general chemistry, D Van Nostrand Company, New York
  • Hopkins BS & Bailar JC 1956, General chemistry for colleges, 5th ed., DC Heath and Co., Boston
  • Lowry TM & Cavell AC 1944, Intermediate chemistry, 3rd ed., Macmillian and Co., London
  • Mills JF 1968, 'Iodine', in CA Hampel (ed.), The encyclopedia of the chemical elements, Reinhold Book Corporation, New York, pp. 290–299
  • Munn B 2000, 'Molecular electronics', in N Hall (ed.), The new chemistry, Cambridge University Press, Cambridge, pp.375–406
  • Nebergall WH, Holtzclaw HF & Schmidt FC 1963, College chemistry with qualitative analysis, 2nd ed., DC Heath, Boston, MA
  • Parsons C & Dover C 1966, The elements and their order: Foundations of inorganic chemistry, Sampson Low, Marston & Co., London
  • Rogers GE 2011, Descriptive, inorganic, coordination, & solid-state chemistry, 3rd ed., Brooks/Cole Cengage Learning, Belmont CA
  • Scharpenseel HW & Becker-Heineman P 1990, 'Overview of the greenhouse effect' in HW Scharpenseel, M Schomaker & A Ayoub (eds), Soils on a warmer Earth, Elsevier, Amsterdam, pp. 1–14
  • Schlesinger HI 1937, General chemistry, 3rd ed., Longmans, Green and Co., New York
  • Shaw BL 1968, Inorganic hydrides, Pergamon, Oxford
  • Sidgwick NV 1950, The chemical elements and their compounds, vol. II, Oxford University Press, London
  • Wiberg N 2001, Inorganic chemistry, Academic Press, San Diego
Interesting analysis. But I still feel that the categories should correspond to the most top-level categories of elements. The topmost level would be "metals", "metalloids" and "nonmetals". "Metals" and "nonmetals" are too large and are broken down further, but still we restrict this to the top two levels to prevent things from being too messy (and also removing problems with division methods not being commonly used or not completely agreed on). The way I see it, "less reactive nonmetals" and "more reactive nonmetals" are third-level categories, parts of the second-level category "typical nonmetals", which is part of the first-level category "nonmetals". Besides, looking at what you have written, there seems to be some disagreement on whether H qualifies as being a "more reactive nonmetal". Double sharp (talk) 07:52, 30 September 2012 (UTC)

Here's what I mean:

Sandbh (talk) 09:13, 30 September 2012 (UTC)

Double sharp: H is relatively inert due to its high bond energy. While H can be very reactive if the conditions are right (heat or a suitable catalyst), such conditional reactivity, as I understand the descriptive chemistry literature, doesn't gel with 'high reactivity' status. Categorizing H as a reactive nonmetal—for sure. Categorizing H as a highly reactive nonmetal—akin to O, F, Cl, Br—no. Sandbh (talk) 13:38, 30 September 2012 (UTC)
You're starting to convince me. :-) What does everyone else think? Double sharp (talk) 09:49, 1 October 2012 (UTC)
Looks nice to me, if the community is willing to listen to me after my gaffe about solid nonmetals :) I'd still like the templates to mention the group names (halogens, etc.) somehow or other — as groups, not as categories. YBG (talk) 03:42, 2 October 2012 (UTC)
I've added a few more (indented) quotes about H, O, S and I. Sandbh (talk) 01:36, 7 October 2012 (UTC)


Since the "halogens" category is going to disappear no matter what proposal we adopt, what category (predicted, of course) should we put elements 117, 167, and 217 into in {{Compact extended periodic table}}? Would 118, 168, and 218 be reasonably able to be predicted as being noble gases? Double sharp (talk) 15:20, 2 October 2012 (UTC)

Is anyone looking at this sub-subsection? Double sharp (talk) 07:20, 26 October 2012 (UTC)
A further problem is that predictions don't help, because those would follow the relativistic Pyykkö model, rather than the non-relativistic Aufbau principle–organized extended periodic table. (Should we change the compact extended table to a Pyykkö one?) Double sharp (talk) 12:01, 16 November 2012 (UTC)
Yeah, good one (and a good two is there too). First of all, I agree, we should switch to Pyykkö. It's, we'll, actual science. It's the most common model nowadays among those who really try to get it. I've seen that in multiple source studying the problem. More often than any other thing about that (in fact, I've never seen anything different).
I also have had the idea we could replace the symbols like Utb with numbers like 132 in the extended table. It's just not comfortable to go through with that many symbols which mean nothing. Numbers make it a much easier understanding. If you think there are rules... Well, yes, there are, but it's more a call for common sense and good navigation than rushing that system.
And yeah, guys, let's try it once again. How about removing the current Halogens section with simple annexing by Other nonmetals before there is an agreement if it could be split?
If the three have their support, we could think about coloring more closely.--R8R Gtrs (talk) 13:02, 16 November 2012 (UTC)
(Well, At should probably be labelled as a metalloid instead of a nonmetal.) Double sharp (talk) 14:07, 16 November 2012 (UTC)
I've coloured At as a metalloid for reasons given above. For my colouring of 117 and 171 as metalloids, I've added quotes from Haire below:
  • 117:
    • "In element 117, the 1− oxidation state becomes less important than that of the lighter group 17 halide ions due to the destabilization of the 7p3/2 orbital....the 3+ state should be at least as important as the 1− state...." (Haire, p. 1728)
    • "Analogous to its lighter homologs, Element 117 should form dimers X2." (Haire, p. 1728)
  • 171:
    • "The energies of these orbitals [9p1/2 and 8p3/2] are so close to each other that this situation is analogous to the nonrelativistic p-shell in the 3d period. Thus, the common oxidation states of elements 167 to 179 will be 3+ to 6+. Element 171 is expected to have many states from 1− to 7+, as do halogens. H(171) would form due to its high electron affinity of 3.0 eV. Compounds with F and O are also expected." (Haire, p. 1733)
Double sharp (talk) 14:07, 16 November 2012 (UTC)
For 118, Haire always compares 118 with its "lighter homologs within the group" (Haire, p. 1728), Xe and Rn, implying that it is a "noble" gas (although it should be more reactive than Xe or Rn). For 172, Haire writes "Element 172 might be a noble gas similar to Xe due to the similar values of their IPs [ionization potentials]. The major difference is that element 172 is predicted to be a liquid or a solid at normal temperatures because of its large atomic weight." (Haire, p. 1733).
This presentation by J. V. Kratz contains another PT extended to the eighth period. He puts 139 and 140 with the other superactinides and moves 169–172 down to the ninth period to join 165–168. This conforms more to Haire and Fricke's predicted electron configurations for the elements until 172. Double sharp (talk) 14:30, 16 November 2012 (UTC)
(off topic) This presentation also states that Fl should be more reactive than Cn(!), and that they should form a new category of elements due to the electron shell closure (gaseous metals). It gives P. Armbruster's prediction that the next closed proton shell is at Z = 122. It also states that Cn to 118 are stabilized against fission because their nuclei are oblate, implying that 119 and 120 should be (according to the presentation you left on my talk page) the last elements we can synthesize for now without new methods. The cross-sections of reactions synthesizing 119 and 120 should also give important information about the end of the periodic table. Double sharp (talk) 14:35, 16 November 2012 (UTC)

Hey, I just realized that a switch to Pyykkö means we need to go alter heavier homologs from like Upo to Uhn in articles like hassium (see infobox). Can someone give it a try?--R8R Gtrs (talk) 17:06, 18 November 2012 (UTC)

Yes check.svg Done Double sharp (talk) 04:06, 19 November 2012 (UTC)
Gaseous metals, work of relativistic effects, are not worth a separate group we (we) could use a new color for. Wouldn't probably be if they were available in macroscopic amounts. There is a group of liquid metals (of one liquid metal, okay), a child of relativity as well-- and none gives a damn for real classification. About Kratz, I don't think he really meant period nine for those six (9p are energetically less stable than 8p, it's gotta be so). I rather think it has a little different meaning (see also the normal, 118 elements table with some super heavies also torn apart for a little).
I like your long table.--R8R Gtrs (talk) 19:26, 16 November 2012 (UTC)
Of course, but relativistic effects make them closer to each other. Besides, we are comparing 9p1/2 and 8p3/2: 9p1/2 would be stabilized while 8p3/2 is destabilized, moving their energy levels closer to each other.
Yes, gaseous metals don't deserve a new colour. But I did change Cn from solid to gas due to this. (I didn't change Fl, since its state and chemical properties seem to be more disputed. More discussion would be nice.) Double sharp (talk) 14:33, 20 November 2012 (UTC)
See #Flerovium. Double sharp (talk) 14:37, 20 November 2012 (UTC)

Yes check.svg Done {{Compact extended periodic table}} now stops at 172 and uses the Pyykkö model. I changed the systematic names to simple atomic numbers: although using the systematic symbols is more consistent with the non-extended table, it's easier for the reader if the number is used, since the reader might not know what the systematic symbols mean. Double sharp (talk) 06:19, 17 November 2012 (UTC)

Categorisation of 117, 118, 171, 172
@Sandbh: Do you agree with my classification of 117 and 171 as metalloids based on Haire's predictions about their properties (quoted above)? Double sharp (talk) 11:12, 19 November 2012 (UTC)
Your question will take me a little longer to respond to; have started to think about it; need to look closer at the figures---off the cuff I'd be surprised if 171 was anything but a metal Sandbh (talk) 11:00, 20 November 2012 (UTC)
Yes, I also find it surprising. I chose a metalloid status for 171 due to Haire's statement that it would form a −1 state and compares it with halogens, but he doesn't mention how stable or common the −1 state would be. Double sharp (talk) 14:29, 20 November 2012 (UTC)
Based on an initial consideration of the limited data on the elements in question, and with a big, big caveat as to uncertainty surrounding relativistic effects, it seems to me that 117 could plausibly (and conservatively) be predicted to be a metalloid (see also Topich 2000 p. 13; Emsely 2003, p. 468); 171 a poor metal; and 118 and 172 = reactive nonmetals. I've made these suggestions largely based on simple (non-relativistic) Goldhammer-Herzfeld criterion ratio extrapolations, together with the impact of the predicted semi-closed valence shell configurations of 117 and 118 as described in their articles. On the basis of current to near-future technology I'm also hugely sceptical that 171 and 172 could ever even be synthesized or stabilized for long enough to observe their properties.
Grateful for the thoughts of others as to the reasonableness of these predictions. Sandbh (talk) 03:32, 24 November 2012 (UTC)
  • Topich J, Solutions manual: Chemistry (McMurray Fay) 2000, 3rd ed., Prentice Hall, Upper Saddle River, NJ: 'Element 117 might have the properties of a semimetal.'
  • Emsley J 2003, Nature's building blocks: An A-Z guide to the elements, Oxford University Press, Oxford: 'From its position in the periodic table, in group 17 below astatine, this element [117] should have the physical properties of a halogen or a metalloid…'
When you are predicting the properties of elements with such high atomic number, you have to consider relativistic effects. Here's B. Fricke's and W. Greiner's paper. Fricke gives this table:
(Well, he puts Y over La, but we have agreed to put Y over Lu.) Most presentations seem to use this table.
Period 8: "...the elements Z = 115, 116, and 117 will have 1, 2, and 3 as their normal oxidation states. The higher oxidation states will be possible only for strong oxidizers. [Its ionization energy should be around 8.2 eV and it should show −1, +1, and +3 oxidation states.] The "noble gas" at Z = 118 will be a very weak noble gas in the sense of He and Ar but as well in comparison to Xe and Rn. The ionization energy is so small [around 9.0 eV] that normal covalent bondings are expected with oxidation states of 4 and 6. The extrapolation of Cunningham expects a boiling point of −15 °C so that it will be nearly a "noble fluid"."
Period 9: Fricke and Greiner state that period 9 will be very much like period 3. "Between Z = 167 and Z = 172 the 9p1/2 and 8p3/2 electrons will be filled in and it is quite an accident that the energy eigenvalues are so close together that a p shell will result very analogous to the 2nd and 3rd period...Z = 171 is expected to have many possible oxidation states between −1 and 7. Element Z = 172 will be a very good noble gas with a closed p shell outside. The ionization energy of this element shown in Fig. 8, is very near to the value of Xe, so that it might be very similar to this element. The great difference Xe and Z = 172 will only be that element Z = 172 is expected to be fluid or even solid because of its large atomic weight." They predict 171 to show mainly the +3 and +7 states, have a first ionization energy of 10.2 eV, a metallic or covalent(?) radius of 165 pm, and a density of 16 g/cm3. 172 is predicted to show the 0, +4, +6, and +8 states, have a first ionization energy of 11.3 eV, a metallic or covalent(?) radius of 220 pm, and a density of 9 g/cm3. They caution that the values for the radii and densities are only first approximations.
So what do you think, based on this and Haire's info (above)? (Pyykkö does not comment on these elements.) Looking at the ionization energies, 117's ionization energy of 8.2 eV is close to that of boron, and 118's value of 9.0 eV is close to those of Cd, Te, and Pt. 171's ionization energy of 10.2 eV is close to that of sulfur, and 172's value of 11.3 eV is close to that of carbon. Double sharp (talk) 06:46, 24 November 2012 (UTC)
Also, the atomic masses of elements 117, 118, 171, and 172 should be 316, 319, 500, and 504 respectively. Double sharp (talk) 06:52, 24 November 2012 (UTC)
If the above link doesn't work, this one should. See also this. Double sharp (talk) 11:38, 24 November 2012 (UTC)
E117 we agree on metalloid. For E171 extrapolated GH criterion ratio is so high that metallic status is near certainty. Only impact of relativity would be to increase likelihood that E171 was a metal (like what happens with Po). Even if it still showed –1 oxidation state that would not be unusual behaviour for a poor metal. Even transition metals can do this (Pt, Au). Nothing in Fricke contradicts. For E118 Fricke etc also say it 'will be a very bad noble gas with possibly very high oxidation states and normal chemical compounds' which I think could reasonably be interpreted as = reactive nonmetal. For E172 they predict outer shell config of 9s29p28p4 with 8p forming a closed subshell. E172 therefore expected to be very good noble fluid or solid, which is a reasonable conclusion. Sandbh (talk) 12:20, 24 November 2012 (UTC)

Thanks for the paper! Here's what I can conclude after reading this:

118 will be a very bad noble gas. Some scientific papers require reading between the lines to correctly interpret them when it jumps from calculations to conclusions. In our case, they still do not refuse to call it a noble gas, but if they called it so no more, it would sound like a sensation back then probably. At least, this would be more interesting to write about. They do mention the reduction of this nobility character, but this shows us they do not think it to be a regular metal. At least not sure in that. The "normal compounds" is a vague term -- is radon difluoride a normal compound? If the answer is yes (which I would pick), then it's not a point-- we still call radon noble. Anyway, such a move (recoloring 118) would be quite bold and thus require more backup proof. Note also it's a part of the FT "Noble gases."

The abstract of the Fricke paper says that 172 is a noble gas but does not say anything about the nature of 118—why not? My guess is because they doubted its bona fides as a noble gas but, in agreement with R8R Gtrs, it would have been too big a call in 1971 to call it something other than a noble gas, without further research.
At two points in the article they refer to 118 as 'the "noble gas" at Z = 118.' The quotes around "noble gas" imply, as I read it, that they regarded 118 as a noble gas only in name and not in substance. As noted, they described 118 as a very bad noble gas and a very weak noble gas even in comparison to Xe and Rn. Not just 'bad' or 'weak' but 'very' as in 'really or truly entitled to the name or designation' (Oxford English Dictionary). And we know Xe forms hundreds of compounds. And cationic behaviour of Rn has been reported.
Our own article on 118 notes that (emphasis added):
'Following the periodic trend, ununoctium would be expected to be slightly more reactive than radon. However, theoretical calculations have shown that it could be quite reactive, so that it probably cannot be considered a noble gas. In addition to being far more reactive than radon, ununoctium may be even more reactive than elements flerovium and copernicium. The reason for the apparent enhancement of the chemical activity of ununoctium relative to radon is an energetic destabilization and a radial expansion of the last occupied 7p-subshell.More precisely, considerable spin–orbit interactions between the 7p electrons with the inert 7s2 electrons, effectively lead to a second valence shell closing at flerovium, and a significant decrease in stabilization of the closed shell of element 118. It has also been calculated that ununoctium, unlike other noble gases, binds an electron with release of energy—or in other words, it exhibits positive electron affinity.
Because of its tremendous polarizability, ununoctium is expected to have an anomalously low ionization energy (similar to that of lead which is 70% of that of radon and significantly smaller than that of flerovium) and a standard state condensed phase.'
On the basis of 118's currently understood properties, a colour change is reasonable. The arguments for so doing are stronger than the arguments for not so doing. Further comments on 171 to follow. Sandbh (talk) 00:02, 25 November 2012 (UTC)
Looking at the ionization potentials of the noble gases (from ionization energies of the elements (data page):
Element He Ne Ar Kr Xe Rn 118 172
IP (eV) 24.587 21.565 15.760 14.000 12.130 10.749 9.0 or 8.7 ? 11.3
In comparison, Fl's ionization potential is around 8.54 eV, and Cn's is around 11.97 eV. Pb's value is a lot lower at 7.417 eV. The 118 value looks like it continues the trend down from Kr reasonably well, and is very close to that of Os. Double sharp (talk) 07:42, 25 November 2012 (UTC)

171 can be an actual metalloid. My first thought after reading the article was even "It's a nonmetal!", but it's probably not the case. I'll try to explain how this went on, and you try to correct me, ok? So, the p electrons split into two parts, the faster the higher Z is. See graph. (These effects alter chem of the elements by 10% and 18-33%, respectively, while the figure for iodine is 1%, and for bromine, chlorine, and fluorine, this is too small to consider, much like we don't consider quantum stuff for macroscopic objects, which is a very very very close approximation, or mass loss during a chemical reaction). The 9p(1/2) electrons are too stabilized and the 8p(3/2) are too destabilized, so they actually very close in energy, and form a p shell of six electrons, which behaves like a single one (despite its contents!). Simply extrapolating that data, we could say that the p energy level is not going to be too close to zero, so it would take a strong oxidizer to get high oxidation states. And also the -1 state seems to be more likely than for 117, both by imagination and according to calculations. 172 is reasonable to stay in its color as well.--R8R Gtrs (talk) 13:01, 24 November 2012 (UTC)

Hmm. I don't understand how 171 could be regarded as a metalloid. Around a quarter of metals exhibit negative oxidation states yet we don't classify any of these as metalloids. On what basis are you suggesting 171 is metalloid? Sandbh (talk) 04:39, 25 November 2012 (UTC)
They don't exhibit negative oxidation states as common states (except Sn and Po) – see List of oxidation states of the elements. We need to consider how important the −1 state is for its chemistry. Haire states that "In element 117, the −1 oxidation state becomes less important than that of the lighter group 17 halide ions due to the destabilization of the 7p3/2 orbital. The EA of element 117 is the smallest in the group (2.6 eV as predicted by Cunningham, 1969 and 1.8 eV as given by Waber et al., 1969). Therefore, the +3 state should be at least as important as the −1 state, so that element 117 might resemble Au3+ in its ion-exchange behavior in halide media." OTOH, he writes for 171: "Element 171 is expected to have many states from −1 to +7, as do halogens. H(171) would form due to its high electron affinity of 3.0 eV (Fricke et al., 1971). Compounds with F and O are also expected." Looking at the electron affinity values of the halogens from electron affinity (data page):
Element F Cl Br I At 117 171
EA (eV) 3.401 3.613 3.364 3.059  ? 2.8 ± 0.2 2.6 or 1.8 3.0
it seems clear that due to its high electron affinity (close to that of I and At), the −1 state of 171 is going to be much more important than that of 117. We must also note that relativistic effects are causing 9p1/2 and 8p3/2 to behave together as one p-shell, and so should not really be compared with how it affects p-shells made of np1/2 and np3/2 subshells with the same n. This p-shell is predicted to behave like the 2p and 3p ones, so that the full shell of 172 is stabilized (making it a very good noble fluid/solid) and making the −1 state of 171 more stable. Double sharp (talk) 07:17, 25 November 2012 (UTC)
Your line of reasoning is plausible. However I am concerned about the EA figure for 171 of 3.0 understood to be given by Fricke et al 1971. Fricke etc give no such figure, as I recall. This is important given the very high EA of gold, due to the potential stability of the filled 6s subshell (look at how 'inert' mercury, with a filled 6s subshell, is), yet even so gold shows no great predilection for the –1 oxidation state. In other words I am querying the validity of the relatively high EA figure given for 171. Sandbh (talk) 12:08, 30 November 2012 (UTC)
Oddly, Haire gives this figure, attributing it to Fricke et al., when it isn't given there... Double sharp (talk) 02:12, 1 December 2012 (UTC)
In Haire's bibliography, he gives two papers by Fricke et al. dating from 1971. One of these is the one I linked to. The other is from Actinides Rev., 1, 433–85. Could this be what he's citing? Double sharp (talk) 02:37, 1 December 2012 (UTC)
If he is citing the other paper it looks like this will be quite hard to get a copy of (try Googling "Actinides Reviews"---very discouraging results) Sandbh (talk) 12:21, 1 December 2012 (UTC)
I found it! :-D Double sharp (talk) 12:26, 1 December 2012 (UTC)
Stunned amazement. Dude, you rock! Sandbh (talk) 12:38, 1 December 2012 (UTC)
It gives the figure of 3.0 eV for 171's EA, and even predicts the properties of the early period 10 elements – the "eka-superactinides" – until 184 (although not placing them into a PT). Double sharp (talk) 12:30, 1 December 2012 (UTC)
OMG and he invokes HSAB principles! Haven't finished reading it yet. May not be able to give feedback until later. Sandbh (talk) 12:46, 1 December 2012 (UTC)
It also states that 171 would be a hard base (comparable to Cl, although it gives Cl's EA as around 3.0 eV(!)), and that H171 would really be a hydrogen halide (unlike AtH and 117H, which are "halogen" hydrides). 172 should be a strong Lewis acid. In this paper, Fricke and Waber dare to call 118 an "in-noble gas", although they then call it a "very weakly noble gas" later in the same sentence. Double sharp (talk) 12:52, 1 December 2012 (UTC)
Hmm. Given 171's similarities to Cl and Br here, shouldn't it really be coloured as a nonmetal?
Double sharp (talk) 11:29, 27 December 2012 (UTC)
Which version of extended periodic table?

Also, after reading the text, I realized that the two schemes in this section is exactly the same, interpreted differently. I like the first one more, and if anyone thinks so not, I can write my arguments.--R8R Gtrs (talk) 13:01, 24 November 2012 (UTC)

I want to hear your arguments. I personally prefer Fricke's (the second one), though. The 5g, 6f, 7d, and 8p1/2 electrons are all being filled in at once in the superactinide series. The 8p1/2 electrons are filled already at 121 to 127, and I don't see why 139 and 140 should be split apart simply to account for the 8p1/2 electrons if they are already there earlier and those two elements are filling the 5g, 6f, and 7d subshells. Pyykkö's argument that the 1385+ and 1386+ ions do not contain 8p1/2 electrons doesn't strike me as particularly convincing – after all, the Eu2+ ion doesn't contain 6s electrons. It seems to just indicate that the 8p1/2 electrons have lower ionization energies than the 5g and 8s ones. For 169–172, the 8p3/2 electrons actually have slightly higher energies than the 9p1/2 electrons (Pyykkö says so, citing Fricke et al. as his reference), and they behave like a single p-subshell analogous to the 2p and 3p subshells. So I think it is better to show how they behave like a single p-subshell due to the fact that their energies are very similar by putting 169–172 in period 9 rather than following the orbitals by putting them in period 8, which also obscures the result of the calculation that the 8p3/2 subshell has higher energy than the 9p1/2 one. Double sharp (talk) 14:48, 24 November 2012 (UTC)

Interestingly, the Fricke paper seems to state that 157 will be in group 3, 158 will be in group 4, etc., and that 164 will really be a group 10 element, despite putting them in groups 5–12 in the periodic table figure given. Double sharp (talk) 14:35, 24 November 2012 (UTC)

However, Haire states that the 9s and 9p1/2 states will be readily available for hybridization, so the fact that 8s are no longer valence electrons might not actually change much. Double sharp (talk) 05:08, 25 November 2012 (UTC)

You know, I did some more thinking. I think it depends on how we define a period. I always thought that the main feature of a period was a constant n+l value, with the exception of the s-block. If a period is a alkali metal--noble gas row, then it's clearly 119--172 without 165-168. I'm ready to accept the need of another two superactinides if I have to. But it still seems weird to me that when we fill up the ninth period when our eight is incomplete, and the pieces being filled (169-172) certainly belong to it (filling the 8p(3/2) orbital), even if the chem is identical. Also, we're finishing a period with a metal for little of reason. But we get thereby a hole of two between 164 and 169, someone needs into there.
You interpret the term "period" slightly differently. I don't know which is right: I'm only using intuition and the known data. That's a more a chem philosophy question anyway.
Sorry for a temporary inability to add some electron configuration arguments (I wanna have my sleep), your arguments are entirely valid and correct. The position is reasonable as well: those Germans chose it for a reason as well. I'm just trying to take a different approach. But I think that debate should ultimately lead to the question "what is a period?" rather than anything. And I understand your position, won't argue if we choose the philosophy to get your variant.
(Also, is what we're discussing here properly reflected on the period 8 element page?)
And at last, I'd love to have a look at Pyykko's paper again (maybe tomorrow), can you bump me a link? (I'm sure I had it somewhere, but don't remember where, or was it another paper?)--R8R Gtrs (talk) 20:03, 24 November 2012 (UTC)
It's not properly reflected on the period 8 element article (it still uses the non-relativistic 119–168 period 8), but I'll try to fix it to talk about the relativistic period 8 instead sometime next week.
Here's a link to Pyykkö's paper.
Yes, finishing a period with a metal is unprecedented in the periodic table. But Fricke et al. predict 164 to be a very good noble metal and to have close similarities (e.g. ionization energy and electron configuration) to 118. Fricke et al. also note that He has a filled s-subshell, Ne–118 have filled p-subshells and 164 has a filled d-subshell. (Haire predicts something different to happen – see Group 12 element#Extensions. Here's another paper solely predicting the properties of 164.) Double sharp (talk) 05:08, 25 November 2012 (UTC)
Helium is not an analogy (much like heavy Pyykko's ions are also weak an argument), different reasons. Whatever. I think it's a philosophy question and not a data one (the data is quite consistent). Thanks for the paper, also! And... Well, given it's a question of arbitrary judgment, I'd use Pyykko's idea as more modern. Have no more principally new arguments; I try not to repeat the same thing (hope you won't either). Well, whichever is fine.--R8R Gtrs (talk) 18:38, 25 November 2012 (UTC)
I don't really think there's any strong reason for ending period 8 at 164, except that 164 is a good noble metal and the next element is an alkali metal. But I do find it better than the alternative (Pyykkö) for reasons I've mentioned previously (and so will not repeat). (Also, the presentation on 114 and 112 being gaseous metals that I linked to earlier uses Fricke's table.) Double sharp (talk) 03:51, 26 November 2012 (UTC)
I changed the template to Fricke as being more consistent with the predicted chemical properties of the elements. (I should rewrite many of the extended PT articles to make them relativistic soon; otherwise, the different forms of the extended PT used on WP will probably confuse readers.) Double sharp (talk) 08:56, 27 November 2012 (UTC)
P.S. Fricke et al. also imply that 154 will be a very good noble metal because its 6f shell is filled(!) (contradicts the electron configuration table I posted below, but then the 5g and 6f shells are buried deep inside) and has no electrons with wave functions outside the (relativistically very stabilized and thus chemically inactive) 8s and 8p1/2 shells, even stating that "[t]his would mean that this element would be chemically very inactive with a behaviour of a noble gas."(!) Double sharp (talk) 14:12, 28 November 2012 (UTC)
P.P.S. Fricke et al. also, contrary to the electron configuration table I posted below, state that the valence electron configurations of 156–164 should be simply 7d2, 7d3, 7d4, ..., 7d10, and that 9s will not be filled in any orbitals. I think using Fricke et al.'s table but Haire's electron configurations is a reasonable choice – Haire's electron configurations are more recent, but there are no very substantial differences, and I think Fricke et al.'s interpretation makes more sense than Pyykkö's for reasons I've already stated above. Double sharp (talk) 14:16, 28 November 2012 (UTC)

Nonmetal subcategories

Do I understand correctly that what is being proposed is three major categories of elements, looking like this(?):

  • Metals: comprising Alkali metals | Alkaline earth metals | Inner transition metals (Ln, An, Super-An etc) | Transition metals | Post-transition metals
  • Metalloids: comprising B, Si, Ge etc
  • Nonmetals: comprising Other nonmetals | Noble gases

Sandbh (talk) 00:50, 17 November 2012 (UTC)

Yes. We can do this as an initial switch, and then discuss more about how to deal with "Other nonmetals". (It's less confusing for readers, as there is then a period where the Halogens colour is unused before it takes a different meaning.) Double sharp (talk) 06:19, 17 November 2012 (UTC)
I have a suggestion for dealing with "Other nonmetals".
he nonmetals can simply be categorised as:
  • Reactive nonmetals: H, C, N, O, P, S, Se
  • Corrosive nonmetals: F, Cl, Br, I
  • Noble gases: He, Ne, Ar, Kr, Xe, Rn
The noble gases are a no brainer.
As per previous citations the rest of the nonmetals (including N) are plainly 'reactive' elements in comparison to the noble gases. That's fine except that the literature also commonly distinguishes between less reactive nonmetals and more reactive nonmetals. Rather than revisit old ground, the less reactive metals can simply be categorised as plain old 'reactive nonmetals' and the more reactive nonmetals as 'corrosive nonmetals' (which they certainly are, unlike the rest of the nonmetals).
It's important to appreciate that each of the proposed categories encompasses a reactivity spectrum rather than being homogenous or necessarily discrete. For the noble gases the reactivity order is (as I recall the research): Ne, He, Ar, Kr, Xe, and Rn (the latter also reportedly showing cationic behaviour). The corrosive nonmetals are easy (hi-lo): F, Cl, Br, I. For the reactive nonmetals my hi-lo guess would be O (by a sizeable margin), H, S, C, Se, P (as black P) and N; with the reactivity of O overlapping some way into the corrosive nonmetals, but without O being recorded in the literature as a 'corrosive' nonmetal.
I know that I've previously argued that oxygen should be categorised as a 'highly reactive' nonmetal, in the same category as F, Cl and Br, however I believe this proposal, as explained so far, is better.
I've also previously argued that iodine is not in the same oxidising power league as its lighter congeners. However, that doesn't necessarily detract from its corrosiveness nor its toxicity. For example, I was surprised to recently learn that tincture of iodine will smoothly dissolve gold. (Nakao Y 1992, 'Dissolution of noble metals in halogen-halide-polar organic solvent systems', Journal of the Chemical Society, Chemical Communications, pp. 426–427).
The 5th edition of Proctor and Hughes' chemical hazards of the workplace (2004) further notes that, 'Iodine in crystalline form or in strong solution is a severe skin irritant; it is not easily removed from the skin, and the lesions resemble thermal burns with brown staining. Cutaneous absorption may be significant and result in systemic symptoms and death.' (pp. 402–403)
Aside from F, Cl, and Br none of the rest of the nonmetals are included in Proctor and Hughes, except for O, as ozone, and P, as 'yellow' P, however neither of the latter allotropes represent the most thermodynamically stable forms of these elements.
Of all of my categorisation suggestions for superseding the 'other nonmetals' category this one is the most consistent with, and well anchored in, the literature, as well as being simple, plausible, non-controversial and (IMO) intuitive. Sandbh (talk) 12:21, 17 November 2012 (UTC)
It certainly is. But I still think am not into it. It is, first of all, counter-intuitive (which is definitely bad). O is not corrosive? The what is it wrong with the old garages standing near my house? Why are their corners brown while they are green? Corrosion is a well-known thing only for oxygen. It's weird that you exclude that given it's not sourced. Also, radon reacts with fluorine at r.t., nitrogen doesn't. How is the word "reactive" relevant? There is no word perfectly describing the situation. At least, we haven't heard it. I can only offer you "other." It's style-neutral. It doesn't say anything, true; but it is therefore not wrong. I think the other should remain for now; I disagree with that this category should be split by any means. Still, I'm open to new suggestions. What would you now say?--R8R Gtrs (talk) 14:20, 17 November 2012 (UTC)
Hello R8R Gtrs, good to hear from you.
  1. O. In suggesting the term 'corrosive nonmetal' I was thinking in terms of hazardous substances (i.e. flesh burning or eating). O, as a strong oxidant, is capable of causing corrosion. But O is not a corrosive substance in the manner of F, Cl, Br and I. Hence O is not listed in Proctor and Hughes. As Wulfsberg (1987, p. 184) notes: '…the halogens (not H2) are very active oxidizing agents that are quite corrosive and must be handled with some care.'
  2. Reactivity. It doesn't matter that Rn reacts with F. It is still called a noble gas. So is Xe even though it forms hundreds of compounds. It doesn't matter that N is relatively inactive. It has a rich chemistry. It is far more reactive than the noble gases. It is clearly a reactive nonmetal in comparison to the noble gases.
  3. Other nonmetals. There is no precedent in the literature for referring to all nonmetals other than noble gases as 'other nonmetals'. If there are only two categories of nonmetals, and one of those is called 'noble gases' why would the rest of the nonmetals be called 'other nonmetals' rather than 'reactive nonmetals', given reactivity was used as a basis to categorize the noble gases? I do not see the logic. As Long & Hentz wrote: '…nonmetals can be split into two groups, the 'noble' or inert gases and the reactive nonmetals.' (1986, p. 84). As per Hill & Holman: 'From left to right across the periodic table, elements change from being reactive metals, through less reactive metals, metalloids, less reactive non-metals to reactive non-metals. (On the extreme right are the noble gases.)' (2000, p. 49).
I'll think some more about all of this. Sandbh (talk) 06:23, 18 November 2012 (UTC)
I'm still against corrosion. No, I mean, it's okay, you can explain it to me and we're good, but millions of people see that table. And most of them will scratch the head about that corrosion doesn't extend to O. Or report an error. I'm simply against giving such a hard time to many people. If even it's referenced, it's counter-intuitive. Not that it's wrong (even though I still think it is). Again, the point is surprising too many readers with no possibility to explain. Not correctness or in correctness. (Not to say corrosive is a subset of reactive)
But you know, I really get your reactivity point. Agreed in the sense we could use the word to replace "Other." (say, if we simply changed the label "other nonmetals" to "reactive nonmetals," would you be satisfied as some kind of compromise?)--R8R Gtrs (talk) 15:24, 18 November 2012 (UTC)
You're right about corrosive nonmetals. Replacing 'other' with 'reactive' seems to be the only logical way to go. The nonmetals can be subcategorized as (a) the noble gases; and (b) the reactive nonmetals. Sandbh (talk) 11:07, 19 November 2012 (UTC)
So, can we now implement this change (i.e. rename "other nonmetals" to "reactive nonmetals", and then annex the "halogens" category into the "reactive nonmetals" category, but putting At as a metalloid)?
I'd rather say yes, but let's see if anyone else has any objections.--R8R Gtrs (talk) 11:23, 19 November 2012 (UTC)

In our multi-category periodic table do we categorise elements on the basis of their most thermodynamically stable states at ambient conditions or their most common form? My question relates to P. Black P is the most stable allotrope and is relatively inert; red P is far more common and relatively stable; white P is the commonest allotrope of all but is unstable. I gather the 'standard state' of P is regarded as being white P on the basis of its ease of preparation, industrial importance and commonality, despite its extreme instability. This approach has never seemed to me to represent good science—provides no basis for valid comparison. Sandbh (talk)

I would rather vote for the white one, becaus e it is commonlĞy considered so, so more people know about this point of view, but you know I am pro-popular in such discussions. We can always describe the nuances in the main P article.-R8R Gtrs (talk) 12:28, 22 November 2012 (UTC)
I was looking at the word 'caustic' as in 'Burning, corrosive, destructive of organic tissue.' (Oxford English Dictionary). Sulfuric acid is caustic, as are phenol and silver nitrate ('lunar caustic'); so is sodium hydroxide. Wondering if 'caustic' could be used as a sub-category of nonmetals. Motivation is concerns that the millions of average readers will expect to see halogens standing out among the nonmetals. If they are annexed as part of the reactive nonmetals they won't stand out. Only a few nonmetals are caustic: F, Cl, Br, I. Of the other reactive nonmetals O2 is corrosive, but that's it; Se is toxic if taken if taken to excess, but that's all: O3 is toxic, corrosive and caustic but is an unstable, uncommon form of O. How to treat white P? Average reader would expect to see white P counted as a caustic nonmetal. Highly unstable structure results in white P being self-igniting near room temperature---and burning white P is obviously caustic. So that would mean caustic nonmetals are F, P, Cl, Br, I. Reactive nonmetals would be H, C, N, O, S, Se. Noble gases are usual culprits. So lighter halogens would still stand out in accordance with common teaching that most reactive nonmetals are on right side of the periodic table (just before noble gases). But they would be accompanied by caustic white P. Seems slightly odd but is byproduct of treating unstable white P as standard state of phosphorus. Comments welcome. Am still thinking about this difficult topic. Sandbh (talk) 12:09, 23 November 2012 (UTC)
I don't know – the halogens are just a group (used in the sense of "vertical column"). So they are not that hard to find. (Although we probably should have a separate key giving the names of the labelled vertical columns, something like "1 – alkali metals; 2 – alkaline earth metals; 11 – etc.", to make sure that it is still quite visible.)
A further note: At is a halogen, but is not marked here. Your table might give the impression to readers that At is not a halogen, especially if they don't read the legend and see that the same colours are being used and assume that nothing has changed. (A few with even less knowledge of chemistry might even think P is a halogen!) There are some cases where people don't seem to read important information – all but one of the comments (abuse is not counted) on the Astatine article is asking for a picture of solid astatine, while the article already states "Elemental astatine has never been viewed, because a mass large enough to be seen (by the naked human eye) would be immediately vaporized by the heat generated by its own radioactivity."
I would personally prefer using the most stable allotrope of each element (i.e. black P instead of white P), but can see reasons for both sides. Double sharp (talk) 13:25, 23 November 2012 (UTC)
Highly reactive nonmetals

Based on all of the lengthy discussion so far, including about O and P, how does the following scheme look(?):

  • Reactive nonmetals: H, C, N, S, Se
  • Highly reactive nonmetals: O, F, P (white), Cl, Br, I
  • Noble gases: usual culprits

Highly reactive nonmetals are those that are either caustic or corrosive, or both. Sandbh (talk) 10:56, 25 November 2012 (UTC)

I think we're (in general) walking in circles. We already had the idea. In principle, I simply don't like the idea of cutting the non-noble nonmetals. There is no name well known by everyone to comply with being a hard scientific term. Like alkali metal, I mean. More reactive, less reactive are just degrees of the reactivity. This is no reason to cut down (what about more reactive transition metals, noble trnasition metals, more chem-rich actinides?). There are halogens, but halogen is not a subset of nonmetals. I personally wouldn't expect them to stand out. There's plenty of everything we've got in books (more reactive, corrosive, etc.), but they are not hard terms. Either a "(said property) nonmetal" or a degree of that. They don't build too strong a picture. To say more, this one would puzzle me also, because, well, I just wouldn't expect that. I honestly think that we should not make our low-educated readers wonder why we chose this. Which is why, in principle, I don't like anything looking unusual for our table. Even "nonmetallic halogens" would be better if I wanted to make the four stand out (but I don't). And even that leaves no idea how to name the others since everyone doesn't like the word "other."
What we're probably going to use (I'm referring to the big green "Reactive nonmetals" group) is quite a propert--R8R Gtrs (talk) 20:27, 25 November 2012 (UTC)y as well, but it's at least one such category instead of two.
  • Hi R8R Gtrs. I don't feel like we've been walking in circles. Rather, it seems to me that we've looked at, considered and discussed a series of categorization suggestions. Most of these were found to be unsatisfactory for scientifically grounded reasons. This is good science in the search for truth. As DePiep said around five months ago, "I know it [element categorization] is old & tough, but isn't solving that what we are here for?"
  • In descriptive chemistry, O, F, P (white), Cl, Br and I are commonly described as being highly reactive. This is an old and well established concept. Just like nitro-glycerine or hydrogen peroxide are described as being highly reactive. There is no soft science in that.
  • This proposal would retain the current number of nonmetal categories, which I think is conceptually a good thing and consistent with the literature.
  • Personally, I don't see a particular need for further cuts e.g. reactive transition metals and noble transition metals but feel free to put up an argument for so doing.
  • I didn't think Wikipedia was written for low-educated readers. As I understand it, Wikipedia is written for readers of average education. Even so, I'm confident that even low-educated readers could easily understand and appreciate the difference between reactive and highly reactive nonmetals.
  • Noble gases aside, it is good, well established chemistry to distinguish between two subcategories of nonmetal based on reactivity. I've put up plenty of citations along those lines. It's just that it's taken a little while to hone in on an accurate way of distinguishing and describing the two subcategories. This is what we've been trying to do for the past five months, through a process of elimination and refinement, and have now succeeded at IMO, with help from lots of contributors.
  • It doesn't matter if it will look a little odd, to have O and P coloured the same as F, Cl, Br and I. Nature is what it is. Chemists will get it---they write about it using these terms. Science professionals will get it. Less educated readers may get a little surprise---F, Cl, Br and I will look familiar in terms of their characteristics but what's the story with O and P? Oh, right, O causes rust, oxidation, corrosion etc, and P burns of its own volition---now I get it :)
  • I can't think of anything else to say. I feel like I've exhausted the plentiful descriptive chemistry literature on this topic. I've run out of intellectual puff (at least for now). Sandbh (talk) 11:58, 28 November 2012 (UTC)
  • Hi Sandbh. What I think is that for all these schemes where we split our non-noble (ignoble? :-P) nonmetals category, we need a lot of explanation. Otherwise you will have readers wondering and asking why element X is not listed as reactive and element Y is when element Z reacts with element X but not element Y, or other similar arguments that have been brought up here before. You can't expect to explain the rationale behind the categorization to every reader, especially when our compact periodic table is on all the elements articles, and do we really want to insert this explanation on every element, even when it is not very relevant (e.g. for the lanthanides)?
Oh, sorry to read that. I don't know if the proposed scheme would need a lot of explanation? Chemists would get it. Science professionals would soon work it out. Other people either wouldn't know any better or would have their curiosity piqued sufficiently by the different colours to want to read further. Which is the beauty of Wikipedia---to facilitate further reading. Same thing happened to me when I first wondered what was the significance of the elements coloured to denote they were 'other nonmetals', as well as what was the basis for colouring some elements as metalloids but not others. I soon worked it out by clicking on the periodic table link included at the top of each element's page. Sandbh (talk) 12:02, 29 November 2012 (UTC)
  • Also, does any authority classify the categories of the periodic table this way? I know you've mentioned a lot of quotes, but does anyone actually split the non-noble nonmetals when colouring a periodic table? There is a difference between an in-depth description of the properties of an element, such as whether it is more or less reactive (which we can cover in the main element articles), and a description that is satisfactory for colour-coding the periodic table. After all, H behaves very strangely in some ways for a nonmetal, which you've mentioned above, and I would expect many authors to cover these oddities in H's behaviour when concentrating on H alone (and not every element). But nobody classifies it as anything other than a nonmetal at STP. Well, I did find one periodic table online (here) which colour-codes H as an alkali metal, but this may be because of its atomic structure rather than its chemical properties. (Sometimes – most of the time, I think – authors simply bail out and simply give it its own category, but later describe it as a nonmetal when covering it separately: when an element is given its own colour on the PT, we obviously have to look at the author's treatment of it when it is covered on its own. Some are even strangely inconsistent, using an "Other nonmetals" category but at the same time colouring H separately(!).) Double sharp (talk) 14:07, 28 November 2012 (UTC)
There are no authorities that I have found that colour a periodic table (as opposed to describing the applicable nonmetals in this way). It's funny. When I think about it most colour their tables into metals, metalloids or nonmetals, or into groups + transition metals, lanthanides etc. Not that many do a good a job as a Wikipedia and quite a few are straight copies of Wikipedia. OTOH, as you note, the distinction between categories such as reactive metals, less reactive metals, metalloids, less reactive nonmetals, more reactive nonmetals, and noble nonmetals is a reasonably common one, at least in writing. In that context, I see no particular issues with colour schemes that draw on or are based around these distinctions. I recall seeing a few periodic tables that classify H as a nonmetal as well as giving it its own colour.
Overall it seems to me that I have the science right, as it is described in chemistry texts, but that I am not 'winning' on the emotional response/feelings front. Sandbh (talk) 12:02, 29 November 2012 (UTC)
I think I've been caught with my foot in my mouth on this page enough to count as one of "our low-educated readers", so I'll add my 2¢ worth here. I initially reacted strongly (pun intended) to the elimination of the halogen category, but then I was enlightened by the cogent discussion that clarified the difference between "categories" (shown in WP with background colors) and "groups" (shown in periodic tables as columns). Now I'm convinced that the halogens don't need a special color. I tend to react slightly to the idea of just two non-metal categories; probably partly a holdover wanting something to replace the halogen category, and partly because if there are only two subcategories of non-metals, it seems like the obvious choices would be "X" and "non-X", but then there isn't a nice way to prefix "non-" onto "noble gas" and make any kind of sense. I tend to agree that it would be nice to get rid of the term "Other nonmetals", but for purely stylistic reasons and not scientific reasons. If the "Other nonmetals" were to the right of the noble gases in the periodic table so that the categories were "X nonmetals", "Y nonmetals" and "Other nonmetals", it might work stylistically. But since the catch-all category is listed before the definite category(ies), stylistically it seems extremely clumsy. If the impressions of this "low educated reader" are helpful, great; otherwise, feel free to ignore them.
But let me ask one nagging question that I have. Given that it seems all have acquiesced to the idea that "halogen" is a group but not a category, does this same argument also apply to the metalic end of the table? Specifically, why should "Alkali metals" and "Alkaline earth metals" exist as categories and not be merely considered groups (columns)? Other than the ever-present thorn-in-the-flesh Hydrogen, is there any reason why these two groups should not be treated the same way this discussion is treating the halogens? YBG (talk) 23:18, 25 November 2012 (UTC)

Becausee At is a halogen but not a nonmetal (it's a metalloid), and the problem gets worse for 117. On the other end of the periodic table (group 1 and 2), no matter how far down you go on the periodic table, the elements are still metals. Double sharp (talk) 03:39, 26 November 2012 (UTC)

Thanks for the clarification. YBG (talk) 03:48, 26 November 2012 (UTC)
Hmm. Reading YGB's comments and nagging question again, and your response Double sharp, raises doubts for me. If they (the s-block metals) are all metals, why do we split them into two groups rather than one category such as s-block metals or reactive metals or some such, an idea which Nergaal and I have both mentioned (and YGB is alluding to? Keeping the two groups presumably on the basis of their different levels of overall reactivity (?) would strengthen the argument for splitting the reactive nonmetals category into two, as previously canvassed. Haven't thought about this too much so feel free to point out any shortcomings in my line of thought. Sandbh (talk) 23:16, 23 February 2013 (UTC)
Proposal #6

Here's a summary of the proposals for renaming and/or subdividing the non-noble nonmetals:

# 1st subcategory 2nd subcategory Categorization basis
1 Core: H, C, N, O, F, P, S, Cl, Se, Br, I
The essential part of a thing
2 Hydrogen: H Typical: C, N, O, F, P, S, Cl, Se, Br, I H is not a typical nonmetal
3 Moderately active: H, C, P, S, Se, I Active: N, O, F, Cl, Br Electronegativity; HSAB principle
4 Unspecified: H, C, N, O, P, S, Se Halogens: F, Cl, Br, I Awkwardness of "Other nonmetals" category
5 Reactive: H, C, N, O, F, P, S, Cl, Se, Br, I
Reactive nometals are reactive compared to noble gases
6 Reactive: H, C, N, P, S, Se, I Highly reactive: O, F, Cl, Br Consistent literature descriptions of "highly reactive" nonmetals as being highly reactive
7 Reactive H, C, N, O, P, S, Se Corrosive: F, Cl, Br, I Corrosive characteristics, as described in literature (overlooked O)
8 Reactive: H, C, N, S, Se Highly reactive: O, F, P, Cl, Br, I Corrosive or caustic characteristics, as described in literature

Of these proposals, #6 was comparably well-received. I like it because there are no issues with allotropes (e.g. P); it preserves the top right hand corner feel for the most reactive nonmetals; it maintains two categories of non-noble nonmetals; it results in a nice progression of subcategories down the halogens; and it looks OK visually (bright yellow colour aside).

Is there any further support for this proposal? Sandbh (talk) 12:21, 1 December 2012 (UTC)

Where is H in proposal #3? Double sharp (talk) 12:22, 1 December 2012 (UTC)
Floating around in the back of my brain :) err, should be on board now Sandbh (talk) 12:31, 1 December 2012 (UTC)
I'm a number 5 man. No breaks for the nonmetal category (which seem a little made up to me, not as obvious as the other breaks we use, e.g. TMs--PTMs, etc.), and you know my other arguments. Also, to get a fairer vote, would anyone bother to note Wp:CHEMISTRY or a few ones like that (have no idea what the public opinion would be, not trying to cheat somehow)?--R8R Gtrs (talk) 20:08, 11 December 2012 (UTC)
Comments sought from WP:CHEMISTRY

Here. Sandbh (talk) 21:42, 1 January 2013 (UTC)

For the record, the invitation was archived here. YBG (talk) 02:19, 25 May 2013 (UTC)

Quantitative properties and nonmetal reactivity

The purpose of this contribution is to provide a quantitative basis for distinguishing between reactive and highly reactive nonmetals. To do this, the following table gives the properties of all the non-noble nonmetals, across nine properties associated with reactivity:

Nonmetal Electron
of dis-
sociation kJ/mol
potential V
Caustic? Corrosive? Pyro-
HSAB Forms
F 334 3.98 159 2.87 1 1 0 H Y 8
Cl 355 3.16 242 1.36 1 1 0 H/B P 7.25
Br 331 2.96 193 1.07 1 1 0 B/S N 6.25
O 147 3.44 498 1.23 0 1 0 H Y 5
I 301 2.66 151 0.54 1 1 0 S N 4
S 207 2.58 266 0.14 0 0 0 S N 2
Se 201 2.55 332 –0.40 0 0 0 S N 2
P 78 2.19 198 0.01 0 0 1 S N 2
N 0 3.04 945 0.27 0 0 0 B N 1.5
H 79 2.20 436 0.00 0 0 0 H N 1
C 128 2.55 346 0.13 0 0 0 S N 0
Average 196 2.85 342 0.66

Note: Caustic = destructive of organic tissue.

If a particular property is quantitative, the last row gives the average value of the listed nonmetals.

I've then used yellow shading to indicate which nonmetals have an above average value for that property, and light grey shading for those that have a below average value (the other way 'round in the case of enthalpy of dissociation). Aqua shading denotes an intermediate value. If a property is binary (e.g. Caustic?) then the distinction between above average and below average is self-explanatory. In the case of HSAB rating I've assigned a value of 1 to 'hard' (H); a value of 0.5 to borderline (B); and a value of 0 to 'soft' (S). If a nonmetal is sometimes listed as more than one HSAB category, I've assigned it the average of the applicable values. In the Forms noble gas compounds? column, Cl has a value of P for possibly since that is the way I read the literature on this question.

The last column shows how many 'above average' property boxes a particular nonmetal has ticked. Since 9 is the greatest number of property boxes that can be ticked it follows that > 4.5 boxes is above average and < 4.5 is below average.

In case anybody is wondering, and as an example, enthalpy of dissociation (or element bond strength) is associated with reactivity: 'The high dissociation enthalpy of the O2 molecule, 498 kJ/mol, is the reason that molecular O. is relatively unreactive and its reactions usually require thermal or photochemical activation.' (Eagleson 1994, p. 768)

On the basis of the above table, nonmetals of above average or high reactivity are F, Cl, Br and O, an outcome that is consistent with the literature.

Overall, there isn't much involved with this approach. It would be expected that any particular nonmetal with an above average number of properties that have above average values for properties associated with reactivty, would have above average or high overall reactivity. I didn't know what the outcome of this approach would be when I started and I didn't really care, because the values would fall where they fell, but I did think that F and Cl would be up there.

Yes, I'm still proposing we distinguish between reactive and highly reactive nonmetals since this is a well established periodic trend in descriptive chemistry, as consistently cited in this thread. The above table provides a non-subjective way of distinguishing between the two categories, by drawing on known values of relevant properties and sorting these into simple above or below average boxes. Sandbh (talk) 11:57, 27 February 2013 (UTC)

  • Eagleson M 1994, Concise encyclopedia chemistry, Walter de Gruyter, Berlin

I'm not well-versed in the WP policies, but I'm wondering how WP:OR applies in this instance. Clearly, the individual entries in the cells are not OR, but I'm not so sure about the conclusion as to where the line should be drawn. I don't feel strongly about this, but I'm just trying to think things through. And just for interest, I made the above table sortable. YBG (talk) 05:38, 28 February 2013 (UTC)

Rawlins, Struble & Gatewood (1961, p. 58) give the nonmetal activity series as Fl, Cl, Br, O, I and S, as do Krauskopf and Beiser (2006, p. 318). So the table reactivity box order is consistent with the literature. Also, in discussing the chemistry of the nonmetals, Cox (2004, p. 147) distinguishes F, Cl, Br and O as good oxidizing agents, and Clugston and Flemming (2000, p. 221) similarly note that F, Cl, Br and O often act as oxidants. So that's consistent with where the above average/below average line happens to fall. Iodine's position in the below average cohort is consistent with the repeated comments it gets about its relatively modest reactivity—I provided eleven citations to this end early on in the Reactive nonmetals and noble gases section. Thank you for making the table sortable. I was a bit tired when I posted it. Sandbh (talk) 11:43, 28 February 2013 (UTC)
  • Clugston MY & Flemming R 2000, Advanced chemistry, Oxford University Press, Oxford
  • Cox PA 2004, Inorganic chemistry, 2nd ed., Instant notes series, Bios Scientific, London
  • Krauskopf KB & Beiser A 2006, The physical universe, 11th ed., McGraw-Hill, New York
  • Rawlins GM, Struble AH & Gatewood CW 1961, Chemistry in action, Heath, Boston
Some more contributions and thoughts about this: first a few more citations, and then about the OR question.
  • 'The alkali metals, such as Cs, K, Na, which tend to lose electrons readily, are powerful reducing agents. Others, like F, O, Cl, Br, are powerful oxidizing agents because they take up electrons readily.' (West 1956, p. 54)
  • 'Oxygen is not the only agent which supports combustion. Fluorine is even more active, and we must also classify as oxidising agents a number of fluoride compounds such as… Chlorine and bromine are also oxidising agents, especially in rich mixtures of hydrogen. Iodine, which usually separates out in non-combined form in explosions, is not.' (Medar 1989, p. 10)
  • 'Carbon is neither a strong metal nor a strong nonmetal and has less electron-attracting power than the strong nonmetals bromine, chlorine, fluorine, and oxygen, in their covalent bond formation.' (Reel 2006, p. 263)
  • 'Iodine is a moderately strong oxidizing agent…' (Young 2006, p. 1285)
  • 'Bromine is a very strong oxidizing agent. Of all the elements, only oxygen, chlorine, and fluorine are stronger.' (Young 2009, p. 1173)
Showing in picture form what is written in the literature is not OR. The literature:
  1. notes a left-right trend across the standard periodic table from very reactive to less reactive metals, followed by metalloids, less reactive nonmetals, and more reactive nonmetals; and then largely by unreactive nonmetals;
  2. says that the most reactive nonmetals are located in the upper right-hand corner, excluding the noble gases;
  3. records a reduction in reactivity going down the halogens and an increase in metallic character;
  4. describes oxygen, fluorine, chlorine and bromine more or less consistently as highly reactive nonmetals, or the like; and
  5. does not consistently describe any other nonmetals in comparable overall terms, apart from noting a few isolated features such as, for example, the relatively high electronegativity of nitrogen or the corrosiveness of iodine.
I don't think I've overlooked anything in the literature about this and am happy to stand corrected. Sandbh (talk) 03:48, 3 March 2013 (UTC)
  • Medard LA 1989, Accidental explosions, vol. 1 (Physical and chemical properties), Ellis Horwood, Chichester
  • Reel KR 2006, The best test preparation for the AP Chemistry exam, 9th ed., Research & Education Assocation, Piscataway, New Jersey
  • West ES 1956, Textbook of biophysical chemistry, 2nd ed., Macmillan, New York
  • Young JA 2006, 'Iodine', Journal of Chemical Education, vol. 83, no. 9, p. 1285
  • Young JA 2009, 'Bromine', Journal of Chemical Education, vol. 86, no. 10, p. 1173
An interesting citation which I haven't been able to quite attribute with 100% certainty. It appears to be from an updated version of an article by Young & Sessine (2000, p. 189), which now sits behind an institution-only pay wall, and none of the libraries near me have access:
'The Periodic Table can be used to predict ability of species to act as oxidizing agents. The reactivity of nonmetallic elements often parallels their electronegativity: the more electronegative the element, the more powerful an oxidant. Fluorine is the strongest oxidant of all the elements. Oxygen, the next most electronegative element, is also a powerful oxidant, as are chlorine and bromine. Elemental nitrogen, however, is only capable of oxidizing a few metals such as lithium and magnesium.' (Young 2006) Sandbh (talk) 11:32, 4 March 2013 (UTC)
  • Young RV & Sessine S (eds) 2000, 'Oxidation', in World of chemistry, Gale Group, Detroit
  • Young RV (ed.) 2006, 'Oxidation' in World of Chemistry, Science Resource Center (now Science in Context), Thomson Gale, Detroit
The following citation is a no-brainer but it illustrates the contribution, in this case, of the two properties of dissociation enthalpy and reduction potential:
'Fluorine is the most reactive of the elements, in part because of the weakness of the F—F bond, (B.E. F—F = 153 kj/mol), but mostly because it is such a powerful oxidizing agent (E° = +2.889 V).' (Masterton & Hurley 2008, p. 556) Sandbh (talk) 11:55, 4 March 2013 (UTC)
  • Masterton WL & Hurley CN 2008, Chemistry: Principles and Reactions, 6th ed., Brooks/Cole Cengage Learning, Belmont, California

A streamlined option

Is there any appetite for (1) replacing the alkali metal, and alkaline earth metal categories, with the single category of s-block metals; and (2) having just two categories of nonmetals: the reactive nonmetals, and the noble gases? I still advocate showing the group names on our periodic table, so the 'alkali metal' and the 'alkaline earth metal' groups would still be identifiable, just as all the other group names would be included. I also still think dividing the reactive metals into reactive and highly reactive categories is markedly more informative chemistry, but I could live with an eight category table as a better construct than what we have now. Sandbh (talk) 11:29, 19 March 2013 (UTC)

re (1): Don't they have distinguishable chemical and physical properties & behaviour? In other words, could you write the article s-block metal without constantly having to separate into two descriptions? And why drop the two well-established names (which include the word "metal", what this categorisation is about) into a mere descriptive, not proper named, one? -DePiep (talk) 15:30, 19 March 2013 (UTC)
Not really. Main differences are reactivity. Article easy to write. I recall reading articles on chemistry of s-block metals. See, frex Advanced Chemistry by Clugston and Rosalind (2000, Oxford University Press), who spend 18 pages on an intregated treatment of the the s-block elements (pp. 280-97). Reactive nonmetals, in contrast, are much, much more diverse. Of course, that does not stop authors of books writing about the chemistry of nonmetals but result is always rambly reading. Drop names for same reason drop halogens: internal logic. Proposal is to keep all three names anyway but as group names not category names. And we can link groups to their articles. See fuller explanation of logic, below. Sandbh (talk) 11:38, 20 March 2013 (UTC)
I tend to agree with DePiep on (1). On (2), you have been persuading me about the reactive/highly reactive categorization, and I am now somewhat convinced (although unsure how best to do this still). But what do others think? Double sharp (talk) 15:51, 19 March 2013 (UTC)
(1): strongly no. DePiep perfectly explains why.
(2): strongly yes. At very least because the 8-categories scheme has undisputed (metalloids maybe aside) category borders. See everything I wrote about it in 2012.--R8R Gtrs (talk) 18:54, 19 March 2013 (UTC)
R8R, just a question, please point to that 8-categories scheme (expected, somewhere on this page, right?). -DePiep (talk) 00:20, 20 March 2013 (UTC)
I should have found it myself, sorry. -DePiep (talk) 09:01, 21 March 2013 (UTC)
Fuller explanation of logic. Our periodic table is based on categories not groups. If we divide the nonmetals into just reactive nonmetals and noble gases then there is no logical reason for dividing the s-block metals, which essentially only differ in their reactivity, into alkali and alkaline earth metal categories. Put another way, the differences in reactivity amongst the reactive nonmetals, not to mention their chemistries, differ much more than is the case with the s-block metals. Yet we propose to lump the non-noble nonmetals all into just the one category of reactive nonmetals and retain the categories of alkali metal and alkaline earth metal. Illogical. OTOH if we divide the reactive nonmetals into (a) reactive nonmetals and (b) highly reactive nonmetals then it makes sense to divide the s-block metals into (a) alkali metal and (b) alkaline earth nonmetals. Either option works, but a mixed logic one doesn't. There is no perfect categorisation scheme but I reckon either of these options are better than the chimera we have now. I mean no disrespect to anybody by calling our current categorisation scheme a chimera however I don't believe it has ever been subject to some thorough analysis. PS R8R: Minor quibble. Borders of transition metals, (arguably lanthanides, actinides), poor metals and what we currently call 'other nonmetals' are not undisputed. Sandbh (talk) 11:40, 20 March 2013 (UTC)
As an open question: The high level categories are metal–metaloid–nonmetal. Using reactiveness as a criteria for further subdivision, is that related to the metalishness of an element? (Or is it like: grouping vehicles in trucks/cars, and then subdivide by color: i.e., using unrelated criteria) -DePiep (talk) 09:01, 21 March 2013 (UTC)
Kind of, in that the presence or absence of metallishness in elements with incomplete valence shells corresponds to the left-right trend across the standard periodic table from very reactive to less reactive metals, followed by metalloids, less reactive nonmetals, and more reactive nonmetals. Sandbh (talk) 13:12, 22 March 2013 (UTC)
You make me (the layman) doubting. This is a good, eh, usefull criterium. Of course our current colors or names do not matter now. -DePiep (talk) 23:43, 2 April 2013 (UTC)
This question: why is this not OR? DePiep (talk) 21:21, 5 April 2013 (UTC)
Hmm. It doesn't advance a new position. It is consistent with literature observations of a more or less steady left-right transition from reactive metals, through less reactive metals, metalloids, less reactive nonmetals, more reactive nonmetals, and inactive nonmetals. It is consistent with an established and associated literature-based division of nonmetals into three sub-categories. It is consistent with statements made in the literature that the most reactive nonmetals (not counting the noble gases) are found in the top right-hand corner of the standard form of periodic table. It is consistent with the literature-stated relationship between the oxidising power and reactivity of non-metals, and the identification of O, F, Cl and Br (and not I) as strong oxidants. It is consistent with statements made in the literature as to the increasing metallicity, and decreasing reactivity, of the heavier nonmetal congeners. It is consistent with literature-based qualitative descriptions of the reactiveness of the nonmetals. Sandbh (talk) 01:38, 6 April 2013 (UTC)
I oppose merging alkali and alkaline earth metals. Isn't the point of color-coding the periodic table to group elements by chemical properties? And alkali and alkaline earth metals have quite different chemical properties.King Jakob C2 12:20, 20 March 2013 (UTC)
Yes, I understand the color codings mostly correspond to broad, higher level chemical patterns, rather than the more distinct chemical properties of individual groups. At this level of categorisation their is no essential difference between the alkali and alkaline earth metals. They are 'typical' very electropositive and reactive elements, forming strongly alkaline oxides, and are almost invariably found in oxidation states expected for ions in noble-gas configs (e.g. Na+, Mg2+). Occur widely in nature in silicate minerals although weathering gives rise to concentrated deposist of halides (e.g. NaCl, CaF2), carbonates (CaCO3) and hydroxides. See, for example Doc Brown ('chemically very similar') or Ramsden 'The s block metals have much in common'. Sandbh (talk) 08:27, 21 March 2013 (UTC)
Your logic is correct. If there were no established organization, I'd use yours (with s-block metals and reactive nonmetals forming two and not four groups). But can't we just say "none knows what 's-block metals' are"? How about making an exception? (The second form the the verb "see" is "saw" after all and not "seeed," as I always wanted it to be, someone's makedmade a exception everyone beginedbegan to follow, and I'm pretty sure there are a lot of people who will be staring at "s-block metals" (or whatever) as amused as if they sawseeed that "seeed" :)--R8R Gtrs (talk) 18:56, 23 March 2013 (UTC)
I like your explanation. Presumably this means we should keep two subcategories of non-noble nonmetals. Sandbh (talk) 09:58, 7 April 2013 (UTC)

The precedent and basis for two nonmetal categories

I want to briefly re-address concerns raised in this thread about splitting the nonmetals in two. Our periodic table has always split the nonmetals into two categories: other nonmetals, and halogens. This split is broadly consistent with the well-established distinction made in the literature between less reactive nonmetals and more reactive nonmetals. Now, if we get rid of the halogens category, concerns have been raised that there is no other established basis to split the nonmetals in two. To alleviate these concerns I've cited several sources referring to:

  • the broad categories of less reactive nonmetals, and more reactive nonmetals (i.e., the well known L-R periodic trend in reactivity);
  • stand-out oxidants among the nonmetals being O, F, Cl and Br, noting that for a nonmetal, reactivity is usually gauged by its ability to serve as an oxidising agent (Brady & Senese 2009); and
  • the patchy reactivity or oxidising power of iodine.

In conclusion, splitting the nonmetals into the categories of reactive nonmetals, and highly reactive metals (O, F, Cl, Br) would be consistent with, and supported by the literature. Sandbh (talk) 09:27, 23 March 2013 (UTC)

Option 10

Subcategorise the nonmetals according to their molecular structures:

Noble gases: He, Ne, Ar, Kr, Xe, Rn
Diatomic nonmetals: H, N, O, F, Cl, Br, I
Polyatomic nonmetals: C, P, S, Se

The lines of demarcation are apparent. Structure generally corresponds to metallishness: Metals generally have high coordination numbers (CNs); metalloids have intermediate CNs; and nonmetals have low CNs, culminating in the noble gases with CN = 0. There are no issues with white P v black P; both are polyatomic.

The terms 'diatomic' and 'polyatomic' are both found in the nonmetal literature: 'Figure 3.2 shows seven nonmetal elements that can exist as diatomic molecules. Atoms of a smaller number of elements can form polyatomic molecules. Two examples shown in Figure 3.2 are phosphorus, which can form P4 (read as "P-four"), and sulfur, which can form S8 (read as "S-eight")." (Miller T 1987, Chemistry: a basic introduction, 4th ed., Wadsworth, Belmont, CA, p. 62)

We have probably all seen periodic tables that highlight the molecular structures of the non-metals (S8, O2 etc).

A similar categorisation pattern can be seen going rightwards across the standard form of the periodic table. Whereas most metals crystallise in close-packed structures with high coordination numbers (8+ to 12, or higher), the poor metals have more complex structures, with lower coordination numbers (4+ to 6+). This can be attributed to the influence of partially covalent bonding in their crystal structures, which dictates fewer nearest neighbours.

It is not a perfect categorisation. But it is simple, and interesting (in my view). Sandbh (talk) 01:58, 7 April 2013 (UTC)

I like it also. From a purely stylistic point of view, categories like "more xxx" and "less xxx" beg the question "Where do you draw the dividing line?" which has the potential to lead to endless discussion, for example on this talk page, to say nothing of the literature which has been cited here. As long as the division between diatomic and polyatomic is clear and unambiguous, that is. I could easily see Diatomic nonmetals and Polyatomic nonmetals articles which would be interesting in themselves. Even if this particular categorization is not selected, I think it points in a good direction: find some characteristic that clearly and unambiguously divides the nonmetals into subcategories. YBG (talk) 15:54, 7 April 2013 (UTC)
When it comes to personal preferences (not regarding the fact it may/may not go), it is my close second, sounds like a good idea, out of box indeed. Like it in general (I really do).
But as always, I'm gonna ruin the fun :(
The problem is: why divide into di- and polyatomic? Even leaving the allotropes problem aside, is the most stable state's structure a property characterizing enough to break a category in two? I mean, why not "reactive nonmetals whose Hungarian names start with F" and "reactive nonmetals whose Hungarian names don't start with F"?
I mean, there are actually relatively sophisticated reasons behind this, but they're not obvious.
It looks like it's a break to break.
In that sense, even our current scheme is better.
I'm in general against mirroring the s-block metals/p-block nonmetals division simply because they're similar.
There's one thing standing behind it: s-block metals are easy to break. They make two equal linear categories, despite being similar in some respects, they differ in hardness, mp/bps, valence, etc. This break is well-established. All overview chem books I know (like Earnshaw&Greenwood) treat them separately. Even, to some extent, the fluorine article: "The alkali metals react with fluorine with a bang (small explosion), while the alkaline earth metals react at room temperature as well but not as aggressively." Those statements were actually around 30 pages apart in the real book. It's worth discussing if they should be drawn together, but (almost) the whole world doesn't, and thus we shouldn't either.
What's the most similar element to sulfur? Right, selenium. To arsenic? Antimony. In almost all cases (except for, sometimes, periods 2 and 6) it's vertical relationship that matters the most. The halogens. The chalcogens/oxygen group. Nitrogen group. Carbon group. Boron group. It's also why most overview chem books divide p-block into periods as well. There's only one more trend of general interest-- metal/nonmetal. But it's hard to describe the nonmetals as a whole. (My school chem book tried to, was very poor at it. My amazing uni book, definitely a few leagues higher than other uni chem books I've seen, talks about groups.) Since we don't do the per group grouping, the metal/nonmetal is the best thing on offer. My whole point there are only two categorizations possible for groups 13--17. Per group (and then we can draw the Uganda flag with p-block (or, okay, the gay flag)). Or per metallicity.
While the terms "polyatomic" and "caustic" and whatever else can be traced to science books, I bet they're not used for ultimate categorization other than caustic/noncaustic. In an actual PT colored AM/AEM/TM/lanthanides/etc./etc./caustic nonmetals/noble gases. I, for example, have never seen such one.
Other categorizations either eyebrow-raising or have nonreasonable (break just to break) breaks (or both). I don't claim they're all such, but all we've seen are, to me at least.
That's my point.--R8R Gtrs (talk) 18:52, 7 April 2013 (UTC)
Points very well taken. Let me add to my list of criteria for division:
  1. Clear. The criterion for division should be easily explained
  2. Unambiguous. It should be (relatively) obvious which category each element fits into
  3. Meaningful. The categories should have significance more than just dividing for the sake of dividing. There should be enough within-group similarity and enough between-group dissimilarity so that each group could be the subject of a separate encyclopedia article.
I think what @R8R is saying is that Option 10 is lacking in the Meaningful category. I'll readily admit that I was quick off the mark because not only because the proposal meets the first two criteria, but also deals so elegantly no only with phosphorus but also with the problem child of every nonmetal categorization: hydrogen. YBG (talk) 05:10, 8 April 2013 (UTC)
Yes, exactly. Agree on your division criteria scheme.--R8R Gtrs (talk) 14:58, 8 April 2013 (UTC)
Hmm. I only have a few comments. R8R Gtrs: I was very pleased to get a close second. That means I only have to give it a nudge to get it into first :)
The proposed division is not concerned with matching the split of the s-block metals. Rather, it's concerned with maintaining, like R8R Gtrs said, the 'established organization' of splitting the non-noble nonmetals into two categories.
As noted, the general meaning of this division is metallicity, which has a well established connection to bonding structure, which in turn has a fundamental connection to atomic structure. I say 'general' since, as with all periodic table categorisations, including our current scheme, there are rub points at the boundaries, as well as overlaps.
In accordance with YBG's elegant criteria, there is sufficient within-group similarity and enough between-group dissimilarity to make this division clearly more than 'a break just to break'. There would be a couple of quite interesting encyclopaedia articles in it. Here's an outline of each sub-category:
  • Diatomic nonmetals. H, N, O, F, Cl, Br, I. Consistent with their low coordination numbers, which are all 1 in this case, the diatomic nonmetals show less metallic character than their polyatomic neighbours. The diatomic nonmetals are mostly highly insulating non-reflective gases that are more electronegative than the polyatomic nonmetals. They all have: lower melting points than the polyatomic nonmetals (in their thermodynamically most stable forms); and lower boiling points than those of the polyatomic nonmetals (bothersome white P included). Boundary phenomena occur with hydrogen (comparatively low electronegativity; seems to act like a metal in some of its chemistry on account of it having a single valence electron); and iodine (lustre, two-dimensional semiconductivity etc).
Postscript: I overlooked the similarity that all the diatomic nonmetals, bromine and iodine included, are volatile at room temperature. I also overlooked the dissimilarity to the polyatomic nonmetals in that, among the latter elements, only white phosphorus (the thermodynamically least stable form of phosphorus) shows any appreciable room temperature volatility. Sandbh (talk) 12:33, 15 April 2013 (UTC)
  • Polyatomic nonmetals. C, P, S, Se. Consistent with their higher coordination numbers (2 to 3) the polyatomic nonmetals show more metallic character. They are all solid, mostly semi-lustrous semiconductors or photoconductors with lower electronegativities than the diatomic metals. S is the poor cousin although even here it is a photoconductor (sometimes described as a semiconductor); it is malleable in its plastic form; it has a well-established cationic chemistry; and its trioxide is a glass-former (as are oxides of P and Se; ditto CO2 but only at 40 GPa). All the polyatomic nonmetals, unlike the diatomic nonmetals, show a marked tendency to catenation and allotropy.
Yes, there are boundary issues. Just as there are with, for example, beryllium (borderline poor); the transition metals (do they/don't they include group 3); gold (king of the metals with multiple nonmetallic properties); the poor metals (do they/don't they include the coinage metals); and radon (borderline metalloid). I don't think these are showstoppers, as long as the categorisation scheme is based on simple, understandable criteria that provide useful insights. Now that I've looked into it some more, this scheme does that very well, IMO. Sandbh (talk) 14:17, 10 April 2013 (UTC)
(re below)

When I don't reply for a few days, it means, I'm taking a broader perspective. It took me a few days to realize that I'm still very doubtful about this.

Like, I started top listen to a lot of indie music much (don't care about trendiness, just like it), but that doesn't mean I would use an indie song to illustrate the music article. That kind of a close second.

Not trying to match s-block? good then (I just like it, nothing more)

"the 'established organization' of splitting the non-noble nonmetals into two categories." I really really feel this doesn't count as a good argument, but I'm not sure if I can prove it. I do understand your point, not just reject it. But I think that if a border isn't clear (since there are a few disputable ways to break 'em in two), it's not a reason to draw one. Moreover, relatively arbitrarily. Ah, I had said I would've been poor at it.

"Here's an outline of each sub-category": here's another one coming. Okay, you can tell me, but you surely won't put it into the template, and how will then the less acknowledged readers get the point apart from main allotrope structure itself?

And this, I think, is why we don't have a common opinion. I want to make it reader-friendly, as reader-friendly as possible, and you want to organize it at your best, and you're good at that. As a guy who could explain you the theory behind this di-/polyatomism, I find it very good (that's how you got the close second, yeah, a good explanation!). As an average reader who hadn't taken in this discussion, I would say, wtf? so num of atoms matters now? why not Hungarian names?

My belief is: If we were writing a book, that, given an appropriate explanation is also there, would be fine and good. A book is not designed for looking through, so this wtfs wouldn't be a problem, as a reader would stay on anyway and we could explain him the point. (The inner me is not opposed to breaking them in two in general, when a reader has a few mins to get the point) Wikipedia is, though, designed for looking though, and even if not, is used for it. This means we have to be as laconic as possible. That's what I don't like about it. A reader won't be thinking. Won't be able to get the point w/o chem education.

Summarizing: He'll be surprised about this previously unseen categorization. Or wtfing. Or a combination. Don't want any of three.

(P.S. If we already have boundary problems, it doesn't mean we should add new. Especially when this can be avoided.)--R8R Gtrs (talk) 20:32, 13 April 2013 (UTC)

I do not think that a concern—based on one's feelings or beliefs or the Hungarian names of elements—as to whether Joe Average will get the point about diatomic and polyatomic nonmetals, should outweigh multiple literature-based arguments and related advantages that support such a scheme. It is a manifestly better scheme than the exemplary wtf 'other nonmetals' category or, what would make matters even worse, a scheme in which the remaining halogens would be annexed into a jumbled 'all sorts' category. Sandbh (talk) 14:06, 14 April 2013 (UTC)
I've prepared a draft makeover of the existing nonmetal article, in my sandbox, using the three proposed sub-categories of noble gases, diatomic nonmetals, and polyatomic nonmetals. Haven't included any new citations yet. The draft reads well and is interesting, in my view. Please have a look and tell me what you think. Sandbh (talk) 06:07, 21 April 2013 (UTC)
I've added a table which compares polyatomic, diatomic and monatomic (noble gas) nonmetals across ten physical and six chemical properties. It shows a nice Escher-like interlocking gradation of properties. Sandbh (talk) 02:21, 27 April 2013 (UTC)
I've added citations to the article and now reckon it's a reasonably good page. Sandbh (talk) 12:45, 2 May 2013 (UTC)
The accompanying table in HTML is {{periodic table (nonmetals variant)}}. -DePiep (talk) 20:31, 18 May 2013 (UTC)
I see that the 'poly-' (Greek polys= "many, much") in polyatomic nonmetals also applies to the many allotropes of the polyatomic nonmetals, as well as their tendency to catenate or form compounds with multiple homoatomic links. The polyatomic nonmetals are thus 'poly-like' in at least three ways. Sandbh (talk) 00:52, 19 May 2013 (UTC)

Request for vote: Polyatomic-diatomic-monatomic nonmetal categorisation

I think my option 10 sandbox draft may be ready, barring any fine-tuning edits. The draft covers and explains, at least to my initial satisfaction, the similarities and differences within and across each of the proposed categories of polyatomic, diatomic and monatomic nonmetal. Would the next step be to call for a vote on option 10? Is there any protocol I need to observe in conducting such a vote? I presume that I should give a preamble setting out the background to the vote; that votes are given as Support or Oppose; and that the majority carries the day? Sandbh (talk) 11:06, 12 May 2013 (UTC)

One single thing, my 2 cents: Whatever the classification, I would not break the article into three poorly connected subarticles with one or two common common sections. Say, the table in metalloids is okay, since it describes what how a metalloid can be seen as a half-metal, half-nonmetal. This one, we can describe without breaking them into three. See also metal.
(Standard disclaimer: don't think I'm the smartest, won't argue, don't care much, I said that and I'm okay with whatever happens next)
I still think that the sheer number of ways to split the non-noble nonmetals, all with good chemical reasons and none clearly standing out from the others (you've suggested many and have succeeded in convincing me that each is a good option!), is an argument in itself not to split them. By all means cover the various properties of the nonmetals that can be used to split them into different categories (I'm afraid to say "groups" for its double meaning), but I would be reluctant to raise only one of them above the others into our periodic table colouring. The fact that despite many printed periodic tables wavering over how to colour the halogens (do they or do they not give them a separate colour), hydrogen, the lanthanides and actinides and other oddball elements, I have yet to find a single instance of them splitting the remaining nonmetals (except sometimes for H), is quite telling IMO. So I wouldn't really be comfortable with something like #10.
My preferance is for #2 (splitting H alone away from the typical nonmetals), with #5 (status quo, with halogen category removed) as a close second; though I sympathise with Nergaal's reluctance to mark any specific element out, I feel that H's very distinctive chemical and physical properties are reason enough to do this for it alone. Double sharp (talk) 11:50, 20 May 2013 (UTC)
BTW, I like the colours you used at {{Periodic table (nonmetals variant)}}. Double sharp (talk) 12:54, 20 May 2013 (UTC)
Double sharp, what is #2 and #5? Anyway, even apart from that and the singling-out H issue, I do not understand what you aim at. What is "typical nonmetal"? All those printed PTs which have different schemes, can you discern good schemes from useless schemes? We only need the good schemes rationality here. As of today, I am with YGB and Sandbh for their rational base. What you write here, like "we don't know do we", is correct by describing the vagueness but does not help us. -DePiep (talk) 21:38, 24 May 2013 (UTC)
Thank you Double sharp. 'Typical nonmetals' is pretty good. It is subjective when it comes to, for example, selenium, which (upon reflection) is arguably not a good example of a 'typical' nonmetal. I suggest therefore that the polyatomic-diatomic division is the best of the lot as it is based on a factual rather than a subjective criterion. I don't think it matters that you or I haven't been able to find a periodic table quite using this division. A periodic table is simply a visual representation of what is written. Everything about the O-10 table has been written before in the literature it's just that no one has so far drawn it. That's probably the same with many Wikipedia pages and drawings---they are all original and simply draw together and represent what is said in the literature. I think we could and should be a little bold with our periodic table, if the result is better, richer template. That kind of approach keeps Wikipedia fresh and serves as an example of the power of a wiki to capture, distill and represent collective wisdom, as found in the literature (but spread out all over the place in this instance).
PS: It occurs to me that the O-10 table is a "double sharp" option in that it is proposing two well-defined sub-categories for the non-noble metals :) :) Sandbh (talk) 11:44, 23 May 2013 (UTC)
PPS: DePiep has been doing the good work on the colours. Sandbh (talk) 11:44, 23 May 2013 (UTC)
Thanks, but I am just following the outcomes here. Can read & understand, but not contribute. And that is me, an academic technician (but not an physicist/chemist). So, I am somewhere halfway between you and our average target WP rearder. -DePiep (talk) 19:37, 24 May 2013 (UTC)
I was going to add option 9 and 10 to the table above, but I wasn't sure whether to append to the table above or to create a new complete table here. And then I couldn't figure out what option 9 was. YBG (talk) 02:48, 25 May 2013 (UTC)

@Sandbh: You are starting once again to convince me. :-) Support. Double sharp (talk) 13:47, 24 June 2013 (UTC)

Selenium – nonmetal or metalloid?

This is the only other plausible candidate for being called a metalloid, and I would be interested in hearing what you (Sandbh) think about Se. Double sharp (talk) 13:44, 6 July 2012 (UTC)

I think its electronegativity (2.55) is a little too high for a metalloid. The electrical conductivity of highly purified pure selenium doesn't cut much chop either, being less than that of bromine. OTOH it does have some metal-like properties the most marked of which is probably its photoconductive capacity. It also has a lustrous appearance, and its structure has been characterized as featuring weakly metallic interchain bonding. So it depends on which criteria are being used to establish metalloid status. If selenium was to be regarded as a metalloid then carbon and phosphorous would probably also have to be admitted into the club, not to mention iodine. From the perspective of the wisdom of the masses, I see that selenium only appears around half as often as polonium and astatine do in the list of metalloid lists and they, in turn, appear around half as often as the recognized metalloids. I can understand what is going on with polonium and astatine but the low appearance frequency of selenium, in light of its established properties, is quite telling. Also relevant is the observation of Rochow (1957), the guy who later wrote one of the few monographs on metalloids, when he said that, 'In some [italics added] respects selenium acts like a metalloid and tellurium certainly does.' Having regard to the literature, I think selenium would probably be better shown as straddling the boundary between metalloids and core nonmetals, along with carbon, phosphorous and iodine. Sandbh (talk) 02:47, 7 July 2012 (UTC)
  • Rochow EG 1957, The chemistry of organometallic compounds, John Wiley & Sons, New York, p. 224
  • Rochow EG 1966, The metalloids, DC Heath and Company, Boston
OK, no selenium then. Double sharp (talk) 05:55, 7 July 2012 (UTC)
It seems that selenium is however regularly categorized as a metalloid in aquatic (as well as soil and/or environmental) chemistry, e.g. '...Selenium traditionally is considered a metalloid in aquatic chemistry...' (Meyer et al. 2005, p. 284) This is curious since it isn't immediately obvious to me what it is about Se that would warrant such a categorization in just these fields of chemistry. Perhaps by association with 'heavy metal' poisoning? Sandbh (talk) 11:55, 9 October 2012 (UTC)
  • Meyer JS, Adams WJ, Brix KV, Luoma SM, Mount DR, Stubblefield WA & Wood CM (eds) 2005, Toxicity of dietborne metals to aquatic organisms, Proceedings from the Pellston Workshop on Toxicity of Dietborne Metals to Aquatic Organisms, 27 July–1 August 2002, Fairmont Hot Springs, British Columbia, Canada, Society of Environmental Toxicology and Chemistry, Pensacola, FL


What should we colour it as? (See Talk:Flerovium.) Double sharp (talk) 14:35, 20 November 2012 (UTC)

Since chemical characterization has been performed, Fl's chemical properties are certainly not unknown, as stated in the current table. However, different studies seem to draw different conclusions regarding its chemical behaviour. Double sharp (talk) 09:08, 27 November 2012 (UTC)
FWIW, zh. colours Fl as a poor metal. Double sharp (talk) 14:16, 18 February 2013 (UTC)

Is anyone looking here, BTW? (This post has two objectives in mind: firstly to "bump" the whole section so it won't get archived for a while longer, and secondly because saying this seemed to make discussion come in the "Predictions" subsection, so I think I should try it again to tie up this particular loose end.) Double sharp (talk) 14:20, 23 March 2013 (UTC)

(pinging people's watchlists) It does appear that this should go down to the bottom, that people may see it better; and yet I am loath to separate it from its natural context... Double sharp (talk) 14:24, 3 June 2013 (UTC)

Making this go live

When we get our new scheme to go live, we need to:

  1. Replace "post-transition metals" with "poor metals";
  2. Get rid of the halogens category, absorbing F, Cl, Br, and I into "other nonmetals" and At into "metalloids";
  3. Replace "other nonmetals" with "reactive nonmetals";
  4. Other minor things about the extended periodic table (colouring of some 7p and 9/8p elements, layout, and making articles use relativistic models)

Double sharp (talk) 09:08, 27 November 2012 (UTC)

Vote: Proposal to implement option 10

We've been discussing the categories of our periodic table since June last year—nearly 11 months now. The thread originated with sorting out the categorisation of Po (now agreed to be better as a metal) and At (now agreed to be better as a metalloid). It then flowed into what to do about the halogen category, given the change in category of At, and if we could come up with something more useful than the nondescript 'other nonmetal' category.

After working through numerous suggestions, YBG proposed that any new categorisation scheme be clear ('The criterion for division should be easily explained'); unambiguous ('It should be relatively obvious which category each element fits into'); and meaningful ('The categories should have significance more than just dividing for the sake of dividing. There should be enough within-group similarity and enough between-group dissimilarity so that each group could be the subject of a separate encyclopaedia article.').

Option 10 divides the nonmetals into the three categories of polyatomic nonmetal (C, P, S, Se); diatomic nonmetal (H, N, O, F, Cl, Br, I); and noble gas (all of which are monatomic). A fully sourced draft rewrite of the nonmetal article, using these proposed categories, can be found here. A draft periodic table template, which includes the two proposed (new) nonmetal categories, can be found at {{periodic table (nonmetals variant)}}. The template includes group names so that the halogens, for example, can (still) be identified. Option 10, in my view, meets all three of YBG's criteria quite well. If it gets up it will unclog the astatine log jam and result in our first ever fully categorised periodic table continuum.

Please vote.

  • Support option 10. Sandbh (talk) 12:26, 17 May 2013 (UTC)
  • Support with my full 2c (I am not a physicist). The criteria YBG mentions, cited here, are very sophisticated and the Sandbh consequences (in his sandbox article) are tough, AFAIKS. Well-thought of, I mean to say. Of course, compared to the current scheme (with "other nonmetal") everything is an improvement, especially because we do not want such an dependent category-name of leftovers. If there are other scheme-basics with a comparable YBG quality (category: internally strong, outerly weak), I'd like to hear. Last thing: every individual element can be diversed (like Po, At, H). That should not keep us from maintaining a serious base for categorisation. -DePiep (talk) 21:49, 24 May 2013 (UTC)
  • Support primarily from a non-scientific perspective: (1) unambiguous categorization (2) no 'none-of-the-above' pseudo category. From a scientific perspective: (3) strong within-category similarity and (4) strong between-category differentiation. I have hesitated to weigh in prematurely: while I am somewhat scientifically literate, I am not a scientist. I think we should advertise this vote more broadly in hopes of getting more input. But before doing that, it might be well to try to summarize the discussion for the benefit of people who come to this without participating in the discussion. YBG (talk) 05:10, 30 May 2013 (UTC)

Implementing option 10

Discussion on option 10 (concluded)
The following is a closed debate. Please do not modify it.
  • Sandbh, who took the initiative for this option 10, implicitly concluded the current result as having reached consensus and closed it ([4] and [5]). The changes can be implemented following the outcomes. Further comments are welcome in a separate section below, #After closure comments. -DePiep (talk) 08:54, 17 August 2013 (UTC)

I'm starting this thread here in order to keep the archive clock ticking on the massive parent thread.

There are four votes in support of this option, which was to divide the nonmetals (aside from the noble gases) into polyatomic and diatomic subcategories, and to show astatine as a metalloid: myself, DePiep, YBG and Double sharp.

A couple of recently discovered references have reminded me to seek to progress option 10. The first ref was Karkhanavala (1973. p. 61) who, in writing about heats of atomization, commented in part that, '…the differences are mainly in the p-block elements of the p3 to p5 configurations which form the di- and poly-atomic molecules.' There is nothing new in this author's observation. I was just struck by the reference to diatomic and polyatomic molecules in groups 13–17, in one sentence. The second reference was Brady and Senese (2009, pp. 858–63) who discuss, at some length, why the diatomic nonmetals form diatomic molecules (due to their electronic configuration, or small size which facilitates pi bonds) and why the remaining nonmetals, not counting the noble gases, form more complex structures (electronic configuration, or larger size: not so good at pi bonds; prefer sigma bonds). I don’t recall seeing such a well illustrated and relatively detailed explanation in any other chemistry textbook.

Anyway, here are my intended and proposed actions, and questions as to the way ahead.

  1. Update the new nonmetal article in my sandbox to incorporate Brady and Senese Done Sandbh (talk) 12:59, 2 August 2013 (UTC)
  2. Post a summary of the parent thread discussion, as to the pros and cons of option 10, here Done (see below) Sandbh (talk) 06:27, 3 August 2013 (UTC)
  3. @YBG: do you remain of the view that we should advertise the vote more broadly? Update: I'll run this proposal past Chemed-l, a Google Groups chemistry education discussion group I subscribe to (> 1,000 members). Sandbh (talk) 12:29, 5 August 2013 (UTC) Update 2: the proposal went out on Tuesday Aug 6. I figure leave it out there for a week. Sandbh (talk) 12:41, 9 August 2013 (UTC) Done (see quite a way below) Sandbh (talk) 11:56, 13 August 2013 (UTC)
  4. Replace the current nonmetal article with the updated new version Update: This step has two parts. 1. Move all the content about allotropes from the current nonmetal article into a new article called Allotropes of the nonmetals. 2. Delete the remaining contents of the current nonmetal article and replace with the option 10 content in my sandbox. @R8R Gtrs: Is this the reorganisation you were referring to in your edit summary of 04:40, 14 August 2013 which said, '(→‎Implementing option 10: am I right to do the reorganization? if not, correct me, please).'? @Double sharp: do you want to be involved in any of this step? Sandbh (talk) 06:52, 16 August 2013 (UTC) Update 2: I took the initiative and went ahead and made the 'glorious edit' (thank you DePiep) to the nonmetal article. Cyber-cigars, champagne (beer or vodka if you prefer) and cavier (real or its soy equivalent), all round. Oh, and Done. Sandbh (talk) 08:18, 17 August 2013 (UTC)
  5. Introduce the new categorisation scheme to the periodic table article
  6. Roll out the new scheme to the rest of the templates
  7. @DePiep: Would you be able to help with 5 and 6?

Comments welcome. Sandbh (talk) 11:57, 30 July 2013 (UTC)

  • Brady JE & Senese F 2009, Chemistry: Matter and its changes, 5th ed., John Wiley & Sons, Hoboken, NJ.
  • Karkhanavala MD 1973, ‘Properties of elements in relation to the periodic table’, in TR Seshadri (ed.), Mendeleyev's periodic classification of elements and its applications, Proceedings of the symposium held at ITT Kharagpur to celebrate the centenary of Mendeleyev's periodic classification: Under the auspices of the Indian Chemical Society and Indian National Science Academy, Hindustan Publishing Corporation, Delhi, pp. 31–130.
  • re #7 @DePiep: I will help. With background color & legends & smartness. Not with science or sources: I am not a scientist. -DePiep (talk) 22:54, 30 July 2013 (UTC)

While I agree with the idea of more widely advertising the vote, the last time we tried that with WP Chemistry, it went extremely well indeed (not). Double sharp (talk) 16:24, 31 July 2013 (UTC)

Please, Double sharp, state 'Yes'. Elements need clarity. -DePiep (talk) 22:54, 1 August 2013 (UTC)
They do indeed. My point was that the last time we tried contacting WP Chemistry on this matter, we didn't even get a single reply... Double sharp (talk) 11:33, 8 August 2013 (UTC)
  • I kinda missed most of the megadiscussion happening, but there one thing that I thought of pointing out: if we are going to the monoatomic-diatomic-polyatomic division, I am wondering if the separation between the diatomic and polyatomic is not a bit artificial. Sure it is simple, but I am wondering if the separation ought to be molecular vs polymeric nonmetals (in their most stable state). This doesn't mean much of a chance because only S8 should be added to the list of E2 sub-group, but leave out P4 (it is not the most stable allotrope). This is just a thought that I thought of pointing out. Nergaal (talk) 04:43, 1 August 2013 (UTC)
@Nergaal To me, this reads like a content issue, not implementation issue (nor !voting #10). Since respected contributor Nergaal says I kinda missed most of the megadiscussion happening, I suggest Nergaal tries to pick this up way above (huge it is indeed). Otherwise, contacting users like Sandbh with a question will give more reply & clarity than you might expect. -DePiep (talk) 20:56, 1 August 2013 (UTC)
Nergaal: The existence of diatomic and polyatomic nonmetals arises out of the interaction of atomic and electronic properties. Diatomic nonmetals form diatomic molecules due to either needing just one electron to attain a noble gas configuration or because they are small enough (N, O) to be able to form triple or double bonds to attain noble gas configs. Conventional wisdom is that triple bonding is the limit for main-group elements. Since C needs four electrons to complete its octet, but is still a relatively small atom, it gets around this problem by forming three single sigma bonds and one delocalised pi bond (pi bonding being more characteristic of small atoms), resulting in graphite. The larger size of the remaining non-noble nonmetals weakens their capacity to form multiple bonds, via pi bonding, and they instead form polyatomic structures, featuring two or more single bonds, in order to achieve completed octets. So, the distinction between polyatomic and diatomic nonmetals, as well as being simple, is more fundamental than artificial.
The mega-discussion considered the P question. The leaning was towards the inclusion of white P since this was the standard state of P, rather than black P, the most thermodynamically stable form. Instead of having a prolonged debate about the pros and cons of standard state v most thermodynamically stable state, option 10 accommodates both forms as they are each polyatomic. Therefore P would be counted as a polyatomic nonmetal.
Does that help? Sandbh (talk) 08:05, 2 August 2013 (UTC)
Come to think of it, I think the di- vs poly- is the simplest to grasp. What I was thinking was maybe more correct from some point of views, but much less clear to a non-expert. Nergaal (talk) 09:09, 3 August 2013 (UTC)

Megathanks to Sandbh for summarizing the megadiscussion. WP:WikiThanks to DePiep for thinking through what would need to change. And thank you both (and Double sharp) for your patience and willingness to take my suggestions. I have glanced through the sandbox PT, and it looks like it is ready for prime time. YBG (talk) 06:16, 6 August 2013 (UTC)

In answer to the question above, I do think it would be good to advertise this discussion and the vote broadly, mostly because the discussion has been between a relatively small number of people. However, if invitations have been posted elsewhere without much response, then I'd say that is good enough. Any new advertising should clearly point to the megadiscussion summary and specifically request that interested parties vote in the appropriate place. It would be good to summarize the sorts of outreach that have been done to add credence to the relatively small number of votes. (By the way, I only count three (not four) formal votes that Support the change -- YBG, Sandbh, and DePiep.) YBG (talk) 06:16, 6 August 2013 (UTC)

Mine is just before the start of the "Selenium – nonmetal or metalloid" subsection. As you can see, I took quite some convincing! :-) Double sharp (talk) 10:47, 6 August 2013 (UTC)

Megadiscussion summary

This is a summary of the parent thread discussion, as to the pros and cons of option 10.

The discussion originated with sorting out the categorisation of polonium (now agreed to be better shown as a metal) and astatine (now agreed to be better shown as a metalloid). It then flowed into what to do about the halogen category, given the change in category of astatine, and if we could come up with something more useful than the nondescript 'other nonmetal' category.

We considered at least ten options:
1. core nonmetals (inc. F, Cl, Br, I)
2. hydrogen | typical nonmetals = based on H not being a typical nonmetal
3. moderately active | highly active nonmetals = based on EN, and HSAB principle
3a. moderately electronegative | highly electronegative
3b. typical nonmetals (inc. F, Cl, Br, I)
4. unspecified nonmetals | halogens (just F, Cl, Br, I)
5. reactive nonmetals = as compared to non-reactive noble gases
6. reactive | highly reactive nonmetals = based on literature descriptions
7. reactive | corrosive nonmetals = ditto
8. reactive | highly reactive nonmetals = ditto (caustic or corrosive, or both)
9. s-block metals | reactive nonmetals
10. diatomic nonmetals | polyatomic nonmetals

Along the way concerns and observations were presented about:

  1. the arbitrary nature of some of these distinctions (e.g. there is no 'reactivity' ruler or measure);
  2. the credibility of putting H into its own category;
  3. keeping the alkali and alkaline earth metals as separate categories;
  4. the meaning of the terms 'moderately active' and 'highly active nonmetal';
  5. original research (OR);
  6. cutting nonmetals into two subcategories;
  7. using scientific criteria;
  8. 'other nonmetals' being either an easily understood term or one not conveying any information;
  9. keeping things simple hence having less categories;
  10. what to about P (white or black?);
  11. whether anyone else splits the non-noble nonmetals when coloring a periodic table;
  12. the logic of splitting the s-block metals into two categories;
  13. showing in picture form what is written in the literature as not being OR;
  14. there being no perfect categorisation scheme;
  15. the presence or absence of metallic character in elements with incomplete valence shells corresponding to periodic trends in reactivity and structure
  16. the 'established organization' of splitting the non-noble nonmetals into two categories;
  17. 'boundary issues';
  18. average reader being surprised/puzzled by new nonmetal subcategories;
  19. the many ways to split the non-noble nonmetals, all with good chemical reasons and none clearly standing out from the others, being an argument in itself not to split them.

YBG subsequently proposed that any new categorisation scheme be (a) clear—'The criterion for division should be easily explained'; (b) unambiguous—'It should be relatively obvious which category each element fits into'; and (c) meaningful—'The categories should have significance more than just dividing for the sake of dividing. There should be enough within-group similarity and enough between-group dissimilarity so that each group could be the subject of a separate encyclopaedia article.'

Option 10 divides the nonmetals into the three categories of polyatomic nonmetal (C, P, S, Se); diatomic nonmetal (H, N, O, F, Cl, Br, I); and noble gas (all of which are monatomic). A fully sourced draft rewrite of the nonmetal article, using these proposed categories, can be found here. A draft periodic table template, which includes the two proposed (new) nonmetal categories, can be found at {{periodic table (nonmetals variant)/sandbox}}. The template includes group names so that the halogens, for example, can (still) be identified.

Option 10's pros (e.g. meets YBG's criteria; consistent with, and anchored in, fundamental atomic and electronic properties discussed in the literature) are thought to outweigh any concerns (e.g. 5 OR v 13 literature; 6 v 16 two subcategories; 17 boundaries v 14 no perfection; 19 v YBG's criteria). The previous sentence is a high-level summary and will not necessarily cover all aspects and nuances of this massive discussion. Sandbh (talk) 06:27, 3 August 2013 (UTC)

HAHAHAHA just checked and apparently in mid-March the massive parent thread already had 189 replies (is this a record?) Double sharp (talk) 17:00, 4 August 2013 (UTC)

m Thanks for destilling this overview, Sandbh. Helpful, especially at this point in the process. I guess Ds enjoyed the destillation too ;-) -DePiep (talk) 20:00, 4 August 2013 (UTC)
Just to say: below is a list of other wiki PT pages to compare. -DePiep (talk) 21:56, 4 August 2013 (UTC)

Hey guys, does this discussion also sets in stone things we agreed on earlier (up the page)? Like group 12 being TM for practical purposes and such?--R8R Gtrs (talk) 10:10, 6 August 2013 (UTC)

I suppose it does (group 12 being TM I'm not so sure about currently, but rest assured that it is probably because I am currently high on Jensen and will probably return to normal once I return to being high on Holleman & Wiberg.) Double sharp (talk) 10:43, 6 August 2013 (UTC)
In archive #15, under 'Checkpoint summary,' my take on the situation was that we agreed p-block metals = poor metals; group 3 membership = Sc, Y, Lu, Lr; that group 12 was worth further arguments or consideration; and that group 11 fell under 'Quibbles: probably not worth revisiting right now.' I'm too far behind on other threads and other things to start anything on group 12 for the forseeable future. Sandbh (talk) 12:14, 6 August 2013 (UTC)
So, (re)introducing poor metal(s) for PTM is definitely not part of option 10? -DePiep (talk) 14:03, 6 August 2013 (UTC)
That one IMHO should be part of it. We did get a consensus for it (see here) and it is a simple rename (no elements actually change colour; the legend just changes a bit). So yes, change "post-transition metals" to "poor metals". Double sharp (talk) 14:29, 6 August 2013 (UTC)
Sandbh, or others: please confirm that changing the category name "post-transition metal(s)" → "poor metal(s)" is part of this decision. -DePiep (talk) 10:47, 8 August 2013 (UTC)
Yes, it was. Part of the reason was to eliminate any argy-bargy as to whether aluminium is or is not a post-transition metal. Sandbh (talk) 12:01, 9 August 2013 (UTC)
I conclude that the category name post-transition metal(s) is to be changed into poor metal(s) name, in option 10. -DePiep (talk) 22:41, 13 August 2013 (UTC)

Is this the place where you intended to have the talk? If not, olease copy wherever it belongs to. I'll manage to track :)--R8R Gtrs (talk) 04:40, 14 August 2013 (UTC)

(Yes, it is about content. Sideissue about place to talk now cleared) -DePiep (talk) 08:16, 14 August 2013 (UTC)

Agree with most of the above, except the nonmetal page. (Please don't take it as a personal attack.) I don't think Sandbh's draft is good enough. I mean, have a look at the metal page. It talks about metals and what makes them metals in first place. It is not concerned with how one can classify them, it is a secondary question for the "metal" topic. Really, breaking the metals set into TMs, alkali metals, etc. is a classification thing. That is why there are some groupings given there (Metal#Categories), often overlapping, and the discussion of those doesn't have a leading role there. It's the way it should be. Analogously it is for the nonmetals. But in the draft, most of description is in the categories part, cut in three. Again, compare with metal.

Also, about 117. Can anyone justify labeling it as whatever (predicted) per RSes? (Maybe there are such sources, just want to be sure)--R8R Gtrs (talk) 19:02, 13 August 2013 (UTC)

Well, nothing personal received really. No problem.
You say that the proposed nonmetal page, that is User:Sandbh/sandbox, is not OK? That would mean we have no RS scientifical base for the option 10 change at all! Could you please contact Sandbh. I mean to say: the first edit, after we decide option 10 is OK, should be to copy Sandbh's nonmetal page into nonmetal. That is the essence.
About 117: of course "whatever" is not for article space. And it is not part of this edit proposal list at all. I suggest you take the discussion further at where that "whatever" is said (I recall it was somewhere, but still it is not part of the edits-todo list). Scientific discussions are elsewhere.
More impotant: this is not the thread you should discuss this. This thread is about: "once decided option 10, what to do". Content discussions are elsewhere. (solved) -DePiep (talk) 22:34, 13 August 2013 (UTC)
To be clear: your content topics are in the wrong place. My replies were for gently. (solved) -DePiep (talk) 23:12, 13 August 2013 (UTC)
Having just now compared metal and User:Sandbh/sandbox, I tend to agree with R8R that the sandbox is rather heavy on the categorization and would benefit from more non-categorization info. However, I then compared it to the current nonmetal article, and the sandbox is significant improvement. Consequently, IMHO we need not wait for further improvement.
By the way, there is a pending proposal to merge metal and nonmetal into Periodic table (metals and nonmetals), which has some problems in that the links on the banners aren't all working quite right. I may try to fix that -- if for no other reason so that I can express my opinion that the articles not be merged.
@DePiep, sorry if my comments are in the wrong place, but I wasn't sure where else to put them. YBG (talk) 02:26, 14 August 2013 (UTC) (We are in the right thread now -DePiep (talk) 09:23, 14 August 2013 (UTC))
So my question is: is the new content for nonmetal accepted or disputed? -DePiep (talk) 23:07, 13 August 2013 (UTC)
For option 10 to make sense, we need diatomic nonmetal, polyatomic nonmetal described somewhere (currently they are linked like nonmetal#diatomic nonmetal, futuristically).
Now, since new text is better than the existing text for nonmetal, using the new text is an improvement in itself -- good. If this is too much to expect, at least we should move the whole new "Categories" section into nonmetal, to cover the new categories (as part of option 10 changes). All other editing, like improving text, bringing it to metal standard, and merging, can be done later as a separate development: standard wiki operation. We should not let such edits hold option 10, they are exterior to the topic. -DePiep (talk) 08:16, 14 August 2013 (UTC)
Absolutely. I actually think that s&bh's sandbox is so great an improvement to the nonmetal article that we could promote it before -- or even without -- option 10. YBG (talk) 08:40, 14 August 2013 (UTC)
Double sharp. I think Sandbh would like to hear your opinion on this (quality of the new nonmetal page). -DePiep (talk) 17:31, 14 August 2013 (UTC)
Having consulted the page more and more today, I state that the nonmetal /Sandbhox (nice ah) is great as it is. Current nonmetal page is "Start" level, the new text can notch it up like two steps. Also consider that the /Shandbox adresses the trends, not the individual elements (as todays nonmetal does). Apart from "but the metal page is better" (so what), I am waiting for arguments against using the full User:Sandbh/sandbox. I want to add that apart from substance, aspects like readability and punctuation are fine too. Being a WP editor, I want to give Sandbh due credit for this proposed improvement. I am preheating my furnace for a new barnstar (the mold I keep for others here, sure). -DePiep (talk) 20:20, 14 August 2013 (UTC)
  • Disambiguation term request

For the new category scheme, we also need a general disambiguation term (WP:DAB). "Option 10" is just for this talk process really. It needs to be international. Because:
Our old en:wp categories, structure and colors, are used in many many other wikis (that's good). Everybody uses the "other nonmetal" category and color, for example see File:Periodic table.svg and [7]. So we cannot overwrite that file on commons with our new categories. Therefore I made a new file, File:Periodic table (polyatomic).svg. We are supposed to use this file everywhere in en:wp, because that is out new cat scheme & coloring. All fine (or to be discussed elsewhere). My question is: is that disambiguation word "(polyatomic)" ok for this? Are other words better: "(multiatomic)", "(periodic table that uses diatomic/polyatomic separation for nonmetals)", ...? I propose for dab, interwiki and commons purposes: use "(polyatomic)" as the disambiguation word, especially to separate from older ("halogen, other nonmetal") categorisation. -DePiep (talk) 20:23, 15 August 2013 (UTC)

-DePiep (talk) 20:23, 15 August 2013 (UTC)

After closure comments

  • Please add follow-up comments below
  • Templates are Go. Most template and image edits are done. See here and [10] or [11] or [12] for August 17.
The Bad words may still appear in article text (and of course Poor metal/Post-transition metal needs a rewrite) - edit when you see one. -DePiep (talk) 14:23, 17 August 2013 (UTC)
Remove. The only categories we show on the Category:Metallic elements page are our PT categories.Sandbh (talk) 21:42, 21 August 2013 (UTC)
Clear. -DePiep (talk) 22:27, 21 August 2013 (UTC) Yes check.svg Done -DePiep (talk) 23:24, 21 August 2013 (UTC)
Next: do we want Category:Polyatomic nonmetals, Category:Diatomic nonmetals? These elements are only in cat:nonmetals and cat:halogens today (in cat:halogens they can stay, for the group reason). -DePiep (talk) 23:24, 21 August 2013 (UTC). Also some cat cleanup & recategorisation done in the neighborhood. See:
Yes check.svg Done -DePiep (talk) 08:48, 22 August 2013 (UTC)
  • Although At has clear association with and properties of halogens it is reasonable to group it with metalloids. Po has some traits of of a poor metal, but is classified as a metalloid more frequently than At. All of the metalloids have properties of poor metals and/or nonmetals; this is their character. If At is grouped with metalloids, then Po should be as well, using a consistent standard. See List of metalloid lists for citations and relative inclusion percentages. Bcharles (talk) 18:33, 22 August 2013 (UTC)
  • Uus (117) is little understood, There is very little evidence that it should be included with metalloids. It is very rarely cited as a metalliod. Lv is more frequently cited as one, though still rarely. It seems clear that Uus should be left with 'unknown physical properties', at least until there are citations showing some form consensus among chemists. Bcharles (talk) 19:25, 22 August 2013 (UTC)
    • First of all, we label 117 as only predicted to be a metalloid. Lv is predicted to have strong metallic properties (common +2 state, unstable +4 state) and no nonmetallic properties, consistent with relativistic effects.
    • As for Po, I would claim that it has almost all the traits of a poor metal and that At's association with the halogens is far less clear. (See the astatine article; it's probably much more metallic than would be expected). Po should be labelled as a poor metal; the only trait I can think of that could give it a claim to metalloidicity are its halides (similar to those of nonmetals), and it forming polonides. The second one is quite irrelevant (Pt and Au can form platinides and aurides too, yet no one calls them metalloids); only the first one seems valid, and it's only one property. Po, I would claim, is overwhelmingly a poor metal.
    • See the beginning of Wikipedia talk:WikiProject Elements/Archive 15 for discussions on the metalloid status of Po and At. Further down the page, the "Predictions" section discusses the predicted chemical statuses of the superheavy elements, synthesized and unsynthesized. Double sharp (talk) 05:44, 23 August 2013 (UTC)
      • Oh, and additionally; the existence of At2 molecules is not universally agreed on (some say yes, some say no), so At should not be placed into the diatomic nonmetals category regardless. Double sharp (talk) 05:48, 23 August 2013 (UTC)
  • Over at Inert pair effect the word "post-transition metal" is kept, after an explanation [13]. -DePiep (talk) 07:49, 27 August 2013 (UTC)

en:wiki consequences for option 10

note: this subsection is for wikitechnical consequences only: bg-color, legend links, &tc. There is no science in here.

If and when option 10 is accepted here at en:WT:ELEM, we want to implement the consequences in en:wp. The decision (consensus) on option 10 is science & source based; the implementation from there is en:wiki-based. This subsection only pertains to the wiki-implementation: just new bg-colors and wikilinks (two each). Other talk, especially including any new categorisation of elements, is science so is not here.

Below is a list of todo's for implementation. Please maintain as a list; #discuss way below. -DePiep (talk) 17:31, 13 August 2013 (UTC)

Decision described

Decisions made by Option 10, 17 August 2013:

  • Nonmetal
Content of page nonmetal will be replaced by content of User:Sandbh/sandbox.
  • Post-transition metals into poor metals (old into new)
Category "post-transition metal(s)" will be renamed "poor metal(s)".
The same for their "(predicted)" categories.
It will cover the same elements.
  • Other nonmetal(s) (old)
The category "other nonmetal(s)" is abolished and will no longer be used. There is no need to maintain a description in article space.
  • Halogen(s) (old)
"Halogen(s)" as a category is abolished and will no longer be used. It will disappear from "category" listings.
The group halogens (group 17) will be unaffected. The word "halogen(s)" may still be used as a group and link to it. Any content should be related to the group, not to the category.
  • Polyatomic nonmetal (new)
"Polyatomic nonmetal" is introduced as a new category. It is defined in the new nonmetal page at first.
Four elements in this category: C, P, S, Se (and none predicted).
Note: this list does not correspond with an abolished category.
  • Diatomic nonmetal (new)
"Diatomic nonmetal" is introduced as a new category. It is defined in the new nonmetal page at first.
Seven elements in this category: H, N, O, F, Cl, Br, I.
Usu (171) is to be 'diatomic nonmetal (predicted)'.
Note: this list does not correspond with an abolished category.
  • Metalloids
Astatine will be moved to category "metalloid".
Ununseptium (Uus, 117) be moved to category "metalloid (predicted)".
  • Color definitions
Mostly used in the {{element cell}}-x templates (parameter 6).
Polyatomic nonmetal
Diatomic nonmetal
Polyatomic nonmetal (predicted)
Diatomic nonmetal (predicted)
  • Disambiguation (DAB interwiki): tbd. Proposed: "(polyatomic)" -- As of August 15, 2013 22:00 UTC.
  • PT after the edits:
Alkali metal Alkaline earth metal Super­actinide Eka-​super­actinide Lan­thanide Actinide Transition metal Post-​transition metal Metalloid Polyatomic nonmetal Diatomic nonmetal Noble gas
predicted predicted predicted predicted     predicted predicted predicted predicted predicted predicted

Edits todo

The subpage lists templates and more that need to be checked & edited in this issue. {{done}} marks to be added. -DePiep (talk) 22:03, 13 August 2013 (UTC)

Discuss todo edits

The "once accepted, what to do" thing. I believe the to-be-accepted scheme, option 10 or if even it were whatever else, does not need to be justified in the nonmetal article. Again, look at metal (a reasonably good article, though not a GA). It does not justify how we break them in the scheme. It just describes metals. The nonmetal article could use the same.

tl;dr Regardless if the article nonmetal will be changed or not, the other changes can go live.--R8R Gtrs (talk) 04:40, 14 August 2013 (UTC)

I don't mind who does the reorganisation. I'd like to hear from DiPiep and Double sharp on this as they have each made significant contributions to the discussion and its associated trappings. Sandbh (talk) 07:30, 14 August 2013 (UTC)
I thought the new nonmetal page is part of option 10. Otherwise our new category names do not exist in articles: diatomic nonmetal, polyatomic nonmetal (they are not described elsewhere). Content & quality in the other thread (because that is scientific). -DePiep (talk) 07:49, 14 August 2013 (UTC)
Images used in other wikis

Trouble ahead, our earlier success bites back. See for example File:Electron shell 001 Hydrogen - no label.svg, used in the infobox. Option 10 says it should turn yellow (diatomic nonmetal). But these images are used in dozens of wikis, all using the old categories (so H should stay green for their "other nonmetal" usage, like in ca:S'està editant Plantilla:Hidrogen). Our earlier success (the element infobox+categorisation) has spread so widely, we cannot edit commons any more :-). -DePiep (talk) 13:06, 14 August 2013 (UTC)

Solved. We do not overwrite that file, but create a new one. We can tell the infobox to use that non-default filename:
|electron shell image=Electron shell 001 Hydrogen (diatomic nonmetal) - no label.svg
See File:Electron shell 001 Hydrogen (diatomic nonmetal) - no label.svg. -DePiep (talk) 13:40, 14 August 2013 (UTC)
This happens with all PT images. See the todo-page for an list of affected images. -DePiep (talk) 17:26, 14 August 2013 (UTC)
Template:Periodic table (p-block trend)

This template needs its own attention. Question: do we color "nonmetal", or do we separate "diatomic", "polyatomic"? The same question exists today, pre-decision (nonmetal or separate "halogen", "other nonmetal"?). Confusing is, until today, that the green color "nonmetal" equals "other nonmetal" (btw, same as in Template:infobox hydrogen today)

Check the preparations please

I am developing the todo edits page, for when option 10 is decided. A great job if you can get it, and a nice one with the right fellows around here. Still, I'd like to have a checking eye. Could anyone (everyone) take a look at that page, and try your favorite page (template, image, ...)? Do you get the change? Late disappointments and errors are worse, really worse.
Here is an anecdote. I did preparation edits in /sandboxes, using find-&-replace on 'Halogen' -> 'diatomic metal'. Great not? Later on I found that [[Halogen|group 17]] should stay halogen. -DePiep (talk) 21:20, 14 August 2013 (UTC)

Addressing active WP:ELEM members: Stone, R8R Gtrs, Double sharp, Nergaal, Sbharris, Materialscientist, Sandbh, DePiep, King jakob c, StringTheory11, TCO, Jacob S-589
-DePiep (talk) 21:33, 14 August 2013 (UTC)

Comments from Chemed-l

There were two replies, one concise and one more elaborate. The concise one was from Eric Scerri, who has been a long-standing member of the list: 'I am happy to support your proposed Wiki reform as to how to treat non-metals.' The elaborate comment, together with my original post and subsequent reply, went as follows.

>Wikipedia is proposing to change its periodic table nonmetal categories. Currently these are:

>Other nonmetals : H, C, N, O, P. S, Se
>Halogens: F, Cl, Br, I, At
>Noble gases: He, Ne etc
>See, for example <>
>The proposed subcategories are:
>Diatomic nonmetals: H, N, O, F, Cl, Br, I
>Polyatomic nonmetals: C, P, S, Se
>Noble gases: no change
>See <>
>Note, in particular, that the halogens are retained (as a group, rather than as a nonmetal subcategory).
>Reasons for the proposed change are (a) dissatisfaction with the blandness, low information content, and left-over nature of the term ‘other nonmetals’; and (b) to accommodate astatine being shown as a metalloid.
>The proposed division into polyatomic and diatomic nonmetals is thought to be clear (easily explained), unambiguous (easily discerned) and meaningful (sufficient similarities and differences within and between each subcategory). A draft rewrite of the nonmetal article, using these proposed categories, can be found here:
>Comments are welcome and can be posted here or on Wikipedia, at See item 12, ‘Implementing option 10.’ Further, item 12.1 'Megadiscussion summary' gives a précis of the other nine options that were considered, and concerns and observations raised along the way. You may also like to vote in support of (Support) or opposition to (Oppose) this proposal: see item 1.7, 'Vote: Proposal to implement option 10'. You do not need a Wikipedia account to post comments to Wikipedia or to lodge a vote; however your IP address will show on the applicable Wikipedia page, if you do. (There are quite a few "IP editors" as they are called, who do just that rather than create a Wikipedia account.)
>Declaration: I am a member of the Wikipedia 'Elements' Project, in whose talk page the above proposal (which I put forward) has been progressed.

a) is good, and makes the proposed change worthwhile.

I'm not too excited about the category of polyatomic nonmetal, but that doesn't matter much.

>>On behalf of the Wikipedia 'Elements' Project, many thanks for your response.

General comments...

The categorization is soft, as you note. I think it would be good to be upfront with that -- right at the start of the intro. The idea of metals and nonmetals is useful -- and it is clear at the edges. The more you go on, the less clear it becomes. The page spends a lot of time dealing with that, justifying or explaining this or that, and noting special cases. By being upfront that the whole scheme is somewhat arbitrary, i think it would make the whole page easier.

>>Sound advice; will see what I can do.

The Categories section starts with

 "Nonmetals have structures in which each atom usually forms (8 - N) bonds
with (8 - N) nearest neighbours, where N is the applicable group number."

First, that leads to the prediction that halogens form -9 bonds. :-) (There were advantages of the old system for numbering groups.)

>>Headslap! Still stuck in the boomer era :)

Rather than "fix" the formula, I think it might be better to use the PT directly. Elements in the right hand group form zero bonds, elements in the group one in "usually" form 1 bond (in the same sense you meant it above.) Less formula, more PT. (I'm assuming you don't want to get in to valence electrons at this point.)

>>I see that the 8-N rule is sometimes regarded as not applying to metals given their much higher coordination numbers, or that it has sometimes been expressed as the 18-N rule, or that N is sometimes instead taken as the number of outer electrons. All this points to a need to refine the wording of this section, as you observed.

Second, that intro statement to that section gives equal importance to two ideas: number of bonds and number of neighbors. I don't think they are of equal importance at all. Bond number is fundamental -- and comes from the PT. Neighbor number is complicated. I gave a double take when you talked about C having three neighbors, and worried about N only having one. Yes, graphite may be the standard state of C, but as you note that is somewhat arbitrary. Associating three as a key number for C seems odd, even confusing. (And it's not exactly true, even for graphite. There is interaction between C in different planes.)

>>I'll look at the wording here. The standard state is certainly arbitrary when it comes to (white) P, this being the most unstable and reactive form whereas all the other standard states of the elements, including graphite, are in their most thermodynamically stable forms at ambient conditions. Mention of the peculiar structure of graphite could be elaborated to better explain how each atom completes its octet e.g., 'Graphite's honeycomb network violates the 8-N rule (carbon is three-bonded), but pi-bonding satisfies the octet rule.'

The topic is supposed to be something fundamental about the PT. Discussing the normal bonding number (from the group number) is good. Neighbor number is complicated, requiring introducing the more complex ideas of multiple bonds -- which really have nothing to do with the topic at hand.

>>From my reading of the literature, the three concepts of normal bonding number, neighbour number, and multiple bonds are more or less interrelated. This can be seen in the left-right reduction across the PT in numbers of nearest neighbours in elemental structures, and in declining normal bonding numbers amongst the structures of the metalloids and nonmetals. Same thing happens going down the p-block e.g. O diatomic, S, Se, and Te polyatomic, and Po metallic (six neighbours). Chemistry text books usually discuss neighbour numbers when describing the p-block groups, starting with the lightest member of each group and then going down the group. They also usually mention the ability of N and O, and sometimes the ability of C, to "dodge" the 8-N rule on account of the relatively small size of their atoms faciliating pi bonding. As I understand it, these L-R and top-down patterns, are, or are related to, fundamental periodic trends arising out of the interaction of atomic and electronic properties. So I'd be hesitant to exclude discussion of neighbour numbers and multiple bonds, whilst fully acknowledging there is room to better explain these things and their relevance.

>>thanks again for all your comments

End of comments and my reply. Sandbh (talk) 11:54, 13 August 2013 (UTC)

Good setup, Sandbh. If I read this right, there are two more supporting !votes with weight & arguments, from outside WP. I understand that you adjusted the future nonmetal page [15] accordingly, today. (PS, a lovely prose this conversation was, I am jealous, given me being chaotic). Another nihil obstat. -DePiep (talk) 23:41, 13 August 2013 (UTC)
Cheers DiPiep. The adjustments I did yesterday where other improvements. I haven't done anything about the second Chemed-l suggestions yet. Sandbh (talk) 07:44, 14 August 2013 (UTC)

A tale of seven elements (2013)

Anybody had a look at this book yet? In chapter 10 'From missing elements to synthetic elements' Scerri discusses the impact of relativistic effects on elements 104 onwards. He notes that such effects peak in period 6 at gold---dubbed the 'gold maximum phenomenon' by Pyykkö. In period 7 he says that calculations by others (Schwerdtfeger & Seth 1998) have shown that the maximum relativistic effect should take place at element 112 (and drop away 'sharply' thereafter). He goes on to write that E112 and E114, contrary to initial predictions and experiments, behave more or less as expected for their place in the period table (E112 per Zn, Cd, Hg; E114 as eka-lead), and that, (again) contrary to earlier speculation, all of this would suggest that the chemistry of E115+ should behave as expected for their periodic table positions. He concludes this chapter by saying, 'This seems to be further testament to the underyling fundamental nature of the periodic law, which continues to stand firm against the threats from quantum mechanics and relativity combined together.' Sandbh (talk) 01:34, 4 August 2013 (UTC)

  • Scerri E 2013, A tale of seven elements, Oxford University Press, Oxford
  • Schwerdtfeger M & Seth M 1998, 'Relativistic effects of the superheavy elements', in P vR Schleyer, NL Allinger, T Clark, J Gasteiger, HF Schaefer III, PR Schreiner (eds), The encyclopedia of computational chemistry, John Wiley & Sons, New York.
Earlier speculation? E115-118 behave pretty much as predicted – it's just the degree (e.g. 118 should be ignoble, though without relativity you wouldn't expect it to be as ignoble as it really is predicted to be). Double sharp (talk) 16:46, 4 August 2013 (UTC)
Oh, the context for my post was what our articles say about 112 ('It is predicted to differ significantly from lighter group 12 elements.') and 114 ('Some studies also suggest that the chemical behaviour of flerovium might in fact be closer to that of the noble gas radon, than to that of lead.'). Whereas Scerri's comments downplay this kind of (memorable) speculation. I know I could fix this myself with some edits however (cue violins of sympathy playing in the backgound) I have quite a few irons in the fire at the moment and only wanted to note what Scerri said, for reference. Sandbh (talk) 06:19, 10 August 2013 (UTC)
Well, the later study on copernicium stated it to be like your average group 12 element, and latest studies of flerovium say that it's a very noble group 14 metal (see Talk:Copernicium, Talk:Flerovium). This could be the reason. (TBH I was kinda suspicious for some time about Fl being a noble gas – consider when Rf was predicted to have a 7s27p2 valence electron configuration and behave like lead, which it didn't. Periodic trends should probably hold up for some more time in the PT, but to diminishing degree – see what I said about E118.) Double sharp (talk) 11:32, 15 August 2013 (UTC)

While we're on the subject of SHE and UHE chemistry predictions

O Sandbh, hast thou finished thy reading of the other Fricke paper with the HSAB principles that I gavest thou the link to? For I would fain be hearing thy comments once again and would rather not overburden the parent massively bloated 2/3-page-taking-up thread. (Feel free to continue reading from there.) Double sharp (talk) 07:16, 5 August 2013 (UTC)

I can wait till the new nonmetal scheme finally gets rolled out though, I suppose. :-) (had enough of bad Early Modern English) Double sharp (talk) 10:49, 6 August 2013 (UTC)
No, strike that, I just realised we can't, unless we want to delay significantly the rolling out of this scheme to the articles that use {{Compact extended periodic table}}. So, my current proposal:

DePiep, please help me beautify the colours. :-) Double sharp (talk) 11:13, 6 August 2013 (UTC)

What is SHE and UHE? Does it have any overlap with the poly- and diatomic thread? -DePiep (talk) 13:54, 6 August 2013 (UTC)
SHE, UHE = superheavy element, ultraheavy element respectively. No formal dividing line, using here SHE = Z=104++ and UHE = Z=119++.
Overlap with poly/diatomic is only really for element 171. This thread is mainly finalizing how we colour elements 117, 118, 171, and 172 in our extended periodic table (which we started discussing in Archive 15 but never actually finished). My current proposal is (all predicted): 117 = metalloid, 118 = noble gas, 171 = diatomic nonmetal, 172 = noble gas. Sandbh and the rest will, I expect, have comments and suggestions.
I think we got consensus in Archive 15 that 117 = metalloid and 172 = noble gas, so it's really about elements 118 and 171. Yet now that reactivity isn't the basis for categorizing the nonmetals, 118 may have problems: it should be quite an ignoble gas, but probably not poly/diatomic!! And 172 is not even a gas. (Note: this is not an argument against option 10, which works very well for the elements we actually experience.) Double sharp (talk) 14:38, 6 August 2013 (UTC)
IIUC: So this thread deals with predicted polyatomic noinmetals and predicted diatomic nonmetals. Then what is the consequence for option 10 introduction? My take is that, once their legend colors & links are defined, there is no reason to halt the introduction. Even when not all extension elements are defenitively categorised (e.g. 171 may change), the option 10 rollout can go ahead. Individual elements can be changed by category easily. -DePiep (talk) 06:32, 7 August 2013 (UTC)
No real consequences, save maybe a few days' delay to get Sandbh to comment on this and a consensus be made regarding 118 and 171 (which shouldn't last long). But I must say that I would prefer to have just one huge change rather than have to have another small change to every single template (like I did running around to correct Po and Am–Cf some time ago; I don't want to do that if possible!), which is why I decided to discuss the categorization of 118 and 171 now instead of later. (Also: look out for element 118 infobox update!) Double sharp (talk) 06:36, 7 August 2013 (UTC)
Their two (predicted) colors are defined (so one can use {{tl|element cell| ... | Polyatomic nonmetal (predicted)}} as regular). See my option 10 notes. -DePiep (talk) 18:50, 6 August 2013 (UTC)
@DePiep: could you make the yellow for predicted diatomic nonmetals a little more greenish, to fit with the basic diatomic nonmetal colour?
Yes, that would be better. -DePiep (talk) 06:22, 7 August 2013 (UTC)

I should really check 171's properties again, as it's very debatable what its structure is like! Double sharp (talk) 05:29, 7 August 2013 (UTC)

Double sharp. Pls go ahead and do not wait for me. I need to inter library loan a specialist book on the HSAB principle, and the timing is not right for me just now to do that. If this eventually results in the need for a recolouring of some extended periodic tables (it may not) I would hope that there would not be quite so many of these as there were non-extended periodic tables. Sandbh (talk) 12:11, 7 August 2013 (UTC)
OK then. I therefore reserve the right to do it this way the other option-10-related changes and let you make comments later. :-)
For anyone interested: my rationale for classifying 118 as a noble gas is basically what R8R Gtrs said in Archive 15 (and now since there's no "reactive nonmetal" subcategory, we have to put it there because it's still almost certainly monatomic in pure form.)
On 171, Fricke (among other things) states that (171) will be a hard base (see HSAB) like Cl, which would seem to make it a nonmetal. (Its electron affinity of 3.0 eV is close to that of I (and a little higher than that of At), so it is probably just a nonmetal in any case.)
What about polyatomic vs. diatomic structure? If 171 is like Cl, it is almost certainly diatomic. If it is more like I, it is a little more debatable. I'd leave it as diatomic until we get clearer info (I'm already searching!) Double sharp (talk) 15:06, 7 August 2013 (UTC)
Attempting to get an answer at the science refdesk. Double sharp (talk) 13:20, 9 August 2013 (UTC)
Quest unsuccessful, it seems... Double sharp (talk) 16:10, 19 August 2013 (UTC)

less categories please?

If we are going to reform the periodic table, may I ask people here to consider removing the tons of categories we already have? Absolutely all the periodic tables I've seen only give one category for metals, and I see no reason to have 6, or 7 categories for them. Here are my proposals; feel free to comment:

  • merge alkalis and alkalines into "s-block metals": what is the difference between the two? in actual chemistry people split transition metals into early and late TMs, but never the s-block
  • merge all nonmetals asides from noble gases into "multy-atomic nonmetals" (as opposed to monoatomic noble gases): what is the point of separating out S, P, S, and Se?
  • merge actinides and lanthanides int "f-block metals" or "intertransitional metals": they are chemically very similar, and only adds an extra color without really adding anything else to the readers
  • possibly rename post-TM into "p-block metals"

Here is how it would look like. Nergaal (talk) 17:39, 6 August 2013 (UTC)

I don't really agree (and have chemical reasons). (Absolutely all periodic tables? That must exclude all of them I've seen that are coloured!)
(1) s-block metals Covered already in Archive 15: they have different properties and can be compared with one another readily (name me one book that compares the s-block elements, not counting H and He, by some OTHER method than group 1/group 2). E.g. density uniformly goes down down group 1, but goes down then up down group 2. Also, as DePiep mentioned there: is it possible to write the article s-block metal without consistently dividing them by group? And the names alkali metal and alkaline earth metal are much more established and are not merely descriptive. Descriptive names are also not too informative. I can see these metals are in the s-block just by looking at the PT. So? Whereas "alkali metal" gives me an inkling that they are somehow related to alkalis (and indeed they are). See Wikipedia talk:WikiProject Elements/Archive 15#A streamlined option. Transition metal splitting is much less clear (except the line between group 12 and the others) and I would leave it as one whole group. We can talk about group 12 another time.
(2) multiatomic nonmetals The polyatomic/diatomic division corresponds neatly with reactivity and metallic character while simultaneously being much more clearly defined. See User:Sandbh/sandbox#Categories. So I would submit that this is quite helpful to the reader. On why to split the nonmetals in the first place, it's been discussed to death at Wikipedia talk:WikiProject Elements/Archive 15 (which is why I won't give a separate section link – it's literally everywhere!)
(3) lanthanides/actinides They are actually quite distinct in chemical properties; early actinides are very different from the early lanthanides (up to around Am) and behave much more like the corresponding transition metals. Meanwhile late actinides can have weird main oxidation states like No having +2 as the main state. The former alone seems to justify splitting them.
(4) p-block metals: very descriptive and not very informative. Would prefer a label which gives far more information about their character than what you see in the PT (I can see they're in the p-block; so?)
So, I would consider Sandbh's Option 10 scheme much more informative and helpful to the reader. Double sharp (talk) 05:09, 7 August 2013 (UTC)
I struggled a while, wanting to have fewer total categories, but ultimately came to support Option 10 because it was easy to envision a unified encyclopedia article about each category, whereas the broader categories had so much variation within them that an encyclopedia article would continually have to talk about the more fine-grained categories. Nevertheless, it might be useful to include "s-block", "p-block", "d-block" and "f-block" on the charts somehow, with sufficient explanation somehow to explain why the groups of elements are labeled with the name of electron shells. I know it is pretty obvious to people in the know, but I suspect it isn't that obvious to the average WP reader. Also, in the table footer that explains the different colors, it might be nice to include the number of elements so classified. YBG (talk) 07:16, 7 August 2013 (UTC)
I'm not really a fan of the block terminology for the reason that the elements in many of them (especially the p-block) are chemically very diverse. It is primarily an atomic category rather than a chemical category; most people who look up the periodic table are probably looking for info from a chemical perspective (ask yourself: what class did you first learn it in at school? Odds are it was chemistry, not physics.), so I wouldn't really want to explicitly mark out the blocks in the periodic table template. In periodic table and block (periodic table), we of course should (and indeed we do) discuss it, but I do not think it should be one of our coloured categories or even should be marked in the legend, because it simply doesn't give much info.
About my "informative" point; this is admittedly somewhat weak, but it is basically that the reader gets more info from seeing "transition metal" (because he now knows there is some sort of transition involved) than seeing "d-block metal" (which will usually get one of two reactions, depending on whether or not the reader in question knows what blocks are in the periodic table: (1) "What on Earth is a d-block"? or (2) "I can see they're in the d-block already just by looking at the table, so? What's your point?") Double sharp (talk) 07:31, 7 August 2013 (UTC)
OK, I suppose including the "block" nomenclature in addition what is already there is trying to make the PT include both Chemistry and Physics info, which is probably trying to cram too much info into it. What about including a count of elements in the legend, so you can tell at a glance that there are 6 Alkali metals, 15 Lanthanides, etc. Could that be done without making things too crammed? YBG (talk) 10:12, 7 August 2013 (UTC)
Not really a major issue, right? I mean, it's good to know there are 15 lanthanides and 15 actinides (those were pretty much the second-to-last and last pieces of the modern periodic table to fall into place), but who really cares that there are XXX transition metals? It's not a really major thing about them... Double sharp (talk) 11:07, 7 August 2013 (UTC)
re two off topic posts:
On marking the blocks. For specialised pages like block (periodic table) we could make a PT that uses our standard categrory colors and that impressively outlines a block by a border. That border should have a legend and a link. A bit like:       s-block       -DePiep (talk) 13:57, 9 August 2013 (UTC)
On adding the number of elements to the legend. Can be done, of course. But does that belong there? The legend entry is there first of all to identify the element property we have marked: what is it? Expanding that with info about that identification (info about that category) is not just zooming in too much, but also crossing the line of wich info should or shouldn't be there. We could end up adding the etymology of the word "alkali" too. But actually that information is better in its place on the alkali metal page itself. One click away. Also there is crowdedness. We have reduced the size of the legend to reduce its brick size: small font, remove text: minimalistic to the essence. Still I think it is crowded, especially when we have these three themes to define.
In the future, such information could be in a popup box that appears when hovering over (probably the alkali metal article lead?). Wikicode does not have that for us yet. References do have that already. -DePiep (talk) 13:57, 9 August 2013 (UTC)
Yea, you're right. I'm always trying to cram in more and more info. I'll let my off-topic ideas sink into well-deserved obscurity oblivion. YBG (talk) 04:21, 10 August 2013 (UTC)

element 171

@Nergaal, you colour 171 as a metalloid here, I wonder why? (I'm also not very sure about it?) Double sharp (talk) 06:32, 10 August 2013 (UTC)

(yes you can see how desparate I am to have someone convince me or myself convince someone XD) Double sharp (talk) 16:02, 10 August 2013 (UTC)
According to this, unseptunium is a metal, nowhere near the metalloids. King Jakob C2 16:35, 10 August 2013 (UTC)
that site is non-relativistic ⇒ I don't really care what it says since it's wrong Double sharp (talk) 03:58, 11 August 2013 (UTC)

Categorisation principles

This post was prompted by Nergaal's request for less categories. It seems to me that the principles by which we categorise the elements are as follows. 1. Start with the basic categories of metals, metalloids, and nonmetals. 2. Subcategorise thereafter to show (a) gradations in metallic character; or (b) other natural distinctions. 3. Aim to achieve an engaging taxonomy, one that is neither excessively fine-grained nor parsimonious.

I think this is why we divide the s-block metals, the inner transition metals, and the non-noble nonmetals into two subcategories apiece. Certainly, before I became an editor, I was captivated by the Wikipedia categorisation scheme, having never seen anything quite as engaging, as far as I can recall, in older sources.

Something else occurred to me about the proposed polyatomic and diatomic subcategories. Texts that discuss the properties of the representative elements usually do so on a group by group basis. Invariably they start with the lightest member and then go down the group. And usually in the case of nonmetals the structure of each element is mentioned e.g. diatomic N with its triple bond resulting in superficially low reactivity, and polyatomic P with its highly strained and reactive structure and, if you're lucky, the much more stable and more metallic black allotrope with its curious polyatomic layered structure. So, the diatomic, polyatomic or monatomic structures of nonmetals form a natural part of such discourses which, in hindsight, is quite neat. Sandbh (talk) 12:27, 9 August 2013 (UTC)

Mixed category elements revisited

  • In general, the current !vote on groups 3 and 12 could affect this discussion. I think the need for mixed categories is reduced. -DePiep (talk) 07:39, 1 December 2013 (UTC)

Categories as content

Content. About: What to mix. The need to describe mixed categories, scientific arguments, encyclopedic considerations. Thoughts per element, or a set of elements. (not: how to color mixes - see below).
-DePiep (talk) 13:24, 17 November 2013 (UTC)

A few of the IP editors have raised the question of mixed category elements. There is an example in the German Wikipedia, here. Se is shown as metalle/halbmetalle; At is shown as metalle/halogene. We (Double Sharp, R8R, DePiep and I) discussed the idea of mixed category elements a while ago. I like them as way of solving thorny categorization questions and avoiding the need for categorisation contortions in order to get every one of the elements into just one our current ten categories. R8R didn't like them for for their lack of clarity; Double sharp didn't like them either; DePiep suggested they could imply a diagonal relationship that may not be there. What's got me going about this again has been the discussions about (1) poor metals & Al: poor metals and where or if Al fits into this category; (2) group 3 and REM: what to about group 3 and Sc, Y, La, Ac, Lu, Lr, and the proposed rare earth category; and (3) Metallicity: the recent posts by the IP editors re the metallicity of the elements.

Before I do much more work re-looking at the possibility of mixed category elements, I'd like to hear what people currently think about this idea. Sandbh (talk) 11:56, 16 November 2013 (UTC)

Stripes: If we're going to stripe, then I prefer the German-style striping, with lots of diagonal stripes: at least this avoids the "diagonal relationship" interpretation. Though I feel that if we need to stripe to be correct, we may need to relook at our category scheme. I just think it should be possible to come up with a classification scheme like that.
How to is continued in: #How to color mixed elements -DePiep (talk) 13:37, 17 November 2013 (UTC)
Al: has some physical-chemical contradiction. Physically it is quite a good metal, chemically it is kind of schizophrenic: its compounds tend to have covalent character, and its oxide is amphoteric, but it is simultaneously strongly electropositive with a high negative electrode potential. I guess I would put it as a pre-transition metal, along with Be, as a sort of outlier in that category, but in that category nonetheless.
Near metalloids: The IP is kinda convincing me to use a "near metalloid" category. I am still thinking about sulfur, iodine, and radon, where their proposed categorization would differ from our current one. I like the way he thinks about diagonals in the periodic table. It is kind of refreshing as I can recite the rows and columns almost without thinking, but diagonals force me to think again like I used to have to some years ago! ;-)
Group 3: personally I feel the physical reasons and some chemical reasons are enough to keep them out of the transition metals. It is not unheard of to do this. And after all, Al has physical reasons and some chemical reasons to be a pre-transition metal: we have a similar situation here. And if you don't consider them transition metals, then one of Jensen's main arguments for including Lu in group 3, periodic trends compared with those among the transition metals, doesn't really hold water. (His main other one is electron configurations, which can be quite easily turned against him, just as I can quite easily split that infinitive for no good reason: do the Aufbau principle's predicted electron configurations really mean anything in the real world?) Now, of course, this is based on my premise that the group 3 elements are not transition metals. You are free to dispute this, as R8R Gtrs does. If you don't accept it, you will probably end up with Jensen's conclusion.
BTW, here's my responses to Jensen's list of attributes of La vs. Lu (Table 2 of his paper). I'll start by saying that I don't really buy the first five items in that table. The first (highest common oxidation state) is neutral; (second) Y group vs Ce group (what happened to the Tb group?) is very much an atomic size issue, and so will be caused simply by periodic trends (La is larger than Sc and Y, while the Ln contraction causes Lu to be much smaller); (third) the crystal structures aren't always the same going down s- or d-block groups; (fourth and fifth) different structures of homologous ionic compounds is not prohibitive to group assignment, viz. NaCl vs. CsCl. I think many of these can be explained by group trends.
A stronger argument of his is sixth, that La has low-lying non-hydrogenlike f-orbitals, which Sc, Y, and Lu do not. Please accept a pause while I contemplate this and whether this is an issue. (First thought is that it is an issue, and that if I'm going to make the case for Sc/Y/La I had better think on this and see whether it is a prohibitive issue.)
Will have to do some more reading regarding the last two items. But from what I can see, superconducting pressure lowers down group 2 from Ca to Ba, therefore something similar may be going on from Sc to La, in which Lu breaks the pressure trend again (despite Jensen's article showing La as superconducting and Sc, Y, and Lu as not). I may be completely wrong on this. Have to go look up info on conduction band structure. Double sharp (talk) 14:40, 16 November 2013 (UTC)
P.S. I guess I didn't need to rationalize through all that mess! It appears that La and Lu are actually both superconducting at atmospheric pressure (naturally, at low temperatures)! This contradicts Jensen's paper: I guess Lu's superconductivity must be a more recent discovery than La's. Well, that's one less argument I have to deal with. (Sc and Y can only do it at high pressure.) Double sharp (talk) 14:44, 16 November 2013 (UTC)
P.P.S. My rationalization appears to be somewhat correct: pressure does indeed play a role in superconductivity. (It even cites my examples of group 2 vs. group 3! Sweet!) Double sharp (talk) 14:47, 16 November 2013 (UTC)
I'm with R8R. Group 3 are TM's physically but chemically only marginally. Mackay, Mackay and Henderson (2002, p. 246) write, 'The scandium group of elements has the outer electronic configuration d1s2 and is formally part of the d block of the Periodic Table. However, as the chemistry is dominated by the III oxidation state, which involves the loss of the d electron, this Group is best regarded as forming a transition region between the s elements and the main d-block.' Similary, Phillips and Williams (1966, p. 4) wrote: 'The metals may be divided into four main classes... (1) The pre-transition metals. These occur in Group IA and IIA of the Periodic Table, and for a number of purposes it also convenient to include with these the Group III metals, Al, Sc and Y… (2) The transition metals. These occur from Group IIIA to Group Ib, although transitional character is not very marked in Sc, Y, and La, while the metals of Group IB also show B-metal character.' I've been thinking about treating Group 3 as mixed category elements, i.e. pre-transition metal|transition metal, so as to do away with much categorisation angst. Sandbh (talk) 02:38, 17 November 2013 (UTC)
  • MacKay KM, MacKay RA & Henderson W 2002, Introduction to modern inorganic chemistry, 6th ed., Nelson Thornes, Cheltenham, ISBN 0748764208
  • Phillips CSG & Williams RJP 1965, Inorganic chemistry, II: Metals, Clarendon Press, Oxford

I think that mixed category is really good solution for too metalloidal nonmetals such as C or Se and it will be good if it will be implied. It could be also implied for poor (chemically) transition metals (such as Au and Pt), which have higher electronegativity in Pauling scale than phosphorus and hydrogen and form relatively stable monoanions. Al and Be are in the poorer chemically group of metals. Group 12 metals are also physically and chemically rather poor.

Lu really looks not like a lanthanoid according to these links. Its popular position is even misleading, maybe erroneous. Lu should be placed below Y. It is quite clear from the papers. Discussion about Lu:

And link from the discussion does not work... Interesting... (talk) 18:23, 16 November 2013 (UTC)

IP, next time keep the cynicism with you and write something helpful. Thanks. -DePiep (talk) 12:38, 17 November 2013 (UTC)
Huh? What cynicism? The post seems all right to me. Double sharp (talk) 14:11, 17 November 2013 (UTC)
Again about German Wikipedia. I think that there are some errors:
The addition "... Interesting..." is. -DePiep (talk) 15:24, 17 November 2013 (UTC)
  • In it only Se is marked as even a "metalloid" (at least C and P have to be also), in fact they (C, P, Se) are the best examples of "near-metalloids" :- elements which are intermediates between nonmetals and metalloids,
  • poor metals are named just as "Metalle" ("metals"; other groups of metals, such as alkali metals, lanthanoids and transition metals are also metals)),
  • below yttrium there is lanthanum (not lutetium) in German Wikipedia,
  • astatine is just a halogen (even not a metalloid)
Example: (no double-categorised elements now (?)) (talk) 19:24, 16 November 2013 (UTC)
Hmm, what happened to the double-categorized elements in de.wp? I could have sworn they were there just a few days ago...
I think that yes, most of these are errors. The only one of these I can see a case being made for is La under Y. I've attempted to make a case for it. Try to convince me that it's wrong! We can only benefit from discussion. Double sharp (talk) 03:58, 17 November 2013 (UTC)

@DePiep: Do you have any thoughts as to a better way to depict mixed category elements, should such a thing eventuate? I'm sure there are other ways to do this besides stripes (which I find to be quite garish), and diagonals. Sandbh (talk) 01:59, 17 November 2013 (UTC)

Re Sandbh: see how to color them below. -DePiep (talk) 13:37, 17 November 2013 (UTC)
  • Since categorization is a scientific issue, we should accommodate any outcome that says: "elements can be in multiple categories". Presentation problems can not prohibit a scientific statement. And since I have seem many elements in the PT being discussed on this, it is time to say: we should make possible to present such mixing. Some questions that arise:
What kind of facts to expect?. How do such mixings appear in facts? Is it always 50/50 over just two categories? Could there be three? Would it need addition of another category to the dozen we have (example: suppose we have a regular cat "PTM", but Al must be in "mixed Poor metal and Metalloid". That would add another cat "PM", and only in a mix at that. May I prohibit this for reasons of being too-detailed? IOW, can you agree there must be found an other solution?). Should we prepare for "expect every variation"?
Always 50/50? If an element is not simply mixed 50/50 over two, do we want that represented? The metalloid border already shows four grades of mixing. I also note that apart from categorizing mixes as facts, we will need some standard article phrasing for all instances. And maybe a section Metal#Categorisation in the periodic table.
It's a detail. The mixed categories of an element are just a detail. In a larger picture, this detail might be omitted. For example, it will be mentioned in the infobox and in a large PT (as we do with, say, atomic mass), but in the smaller PT's (navigation box at end of page) we could forgo this detail. There the element should have a single color (of a 51% category). In intermediate size PT: tbd. -DePiep (talk) 14:16, 17 November 2013 (UTC)

How to color mixed categories

About: how to follow and implement the content decisions. Coloring is just a representation of scientific content. Expect examples in color-to-category, mixing colors, layout options.
-DePiep (talk) 13:24, 17 November 2013 (UTC)
List of examples
Please add your example links to this central bulleted list. Number them distinctly "[demo 1], [demo 2], ..." for easy reference, and maybe add a small description. Discussion is below the list, not in the list. -DePiep (talk) 14:42, 17 November 2013 (UTC)
Used in de:Alternative Periodensysteme. Uses File:Metal-Metaloid.svg and File:Nonmetal-Metaloid.svg. -DePiep (talk) 15:35, 17 November 2013 (UTC)
-sq:Sistemi_periodik_i_elementeve (sq=Shqip=Albanish): the German striped version. -DePiep (talk) 06:32, 18 November 2013 (UTC)
  • [demo 7] all PT images: commons:Category:Periodic_table. -DePiep (talk) 07:12, 18 November 2013 (UTC)
  • [demo 8] commons:File:PSE.png uses a narrow colored bar in the left of cells. It is fading, and not overlapping the text. It shows the columns (groups) like "pnictogens" (not mixed cats), which we do in the column header. -DePiep (talk) 07:12, 18 November 2013 (UTC)


Before choosing a striping pattern, let's find as many options as possible.

  • Split by diagonal, NW-SE. See demo 4 by Sandbh. Could be NE-SW too.
Creates the grouping in a glance visually, more or less (esp. the Ln's and when in 32-column layout). At the same time this introduces a visual cut across the PT right through elements. This is the "diagonal" that possibly misleads the eye and the grasping of the PT. -DePiep (talk) 15:26, 17 November 2013 (UTC)
This surely puts the mixing on the map and into your eye. Even into a distracting level I'd say. It is grabbing all your attention, to just this minor aspect. Even with (our) lighter cat colors, this effect is present. That is because we want those cat colors to be different. A gentle pair of colors that would make a softer striping, would defy the purpose of coloring categories recognizably different.
Also, any striping background makes reading or recognizing text very difficult. It surely is a setback in accessability. It is a technique used in captcha forcing us to spend extra concentration, and we'd multiply that for dozens of elements!
  • Fade-over. demo 5: a color gradient. The direction (horizontal in the demo) can be any degree. Also the gradient can be radial (like waves from a stone thrown in the water), though I don't see an advantage in that for us. -DePiep (talk) 15:26, 17 November 2013 (UTC)
  • Other wikis for inspiration. I have checked every other language wiki's Periodic table page (the iw: links). In these PT pages, only the Albanian PT page (demo 6, sq:wiki=Shqip) uses any sort of color mixing; it uses the German striping. Todo: the striping could be on other pages (like in de:wiki, in "Alternative PT"). -DePiep (talk) 06:32, 18 November 2013 (UTC)
  • demo 8 shows a small, fading colored bar, left side of the element cell. Nice option, since it does not interfere with the text that much. The bar could be at any side (or even top+right). A smaller bar like this is difficult to express a 50/50 mix, that would interfere with the text & symbol. Could use some examples into out topic. -DePiep (talk) 07:12, 18 November 2013 (UTC)
    • In the 32 column PT . Mixing categories/legend/colors is adding one more complication to the PT. To keep oversight, the mixing in graphic PTs should be demo'ed & applied in a 32+ column PT only, not in an 18 column. (and possibly in the large cells, that is: a PT wider than page). -DePiep (talk) 08:18, 19 November 2013 (UTC)
  • Please continue reading below: the tetris option. -DePiep (talk) 07:51, 21 November 2013 (UTC)
Tetris markings
  • Let's use tetris markings! Not exactly coloring, but who does not understand this:
Tetris markings
Hydrogen (diatomic nonmetal)
Helium (noble gas)
Lithium (alkali metal)
Beryllium (alkaline earth metal)
Boron (metalloid)
Carbon (polyatomic nonmetal)
Nitrogen (diatomic nonmetal)
Oxygen (diatomic nonmetal)
Fluorine (diatomic nonmetal)
Neon (noble gas)
Sodium (alkali metal)
Magnesium (alkaline earth metal)
Aluminium (post-transition metal)
Silicon (metalloid)
Phosphorus (polyatomic nonmetal)
Sulfur (polyatomic nonmetal)
Chlorine (diatomic nonmetal)
Argon (noble gas)
Potassium (alkali metal)
Calcium (alkaline earth metal)
Scandium (transition metal)
Titanium (transition metal)
Vanadium (transition metal)
Chromium (transition metal)
Manganese (transition metal)
Iron (transition metal)
Cobalt (transition metal)
Nickel (transition metal)
Copper (transition metal)
Zinc (transition metal)
Gallium (post-transition metal)
Germanium (metalloid)
Arsenic (metalloid)
Selenium (polyatomic nonmetal)
Bromine (diatomic nonmetal)
Krypton (noble gas)
Rubidium (alkali metal)
Strontium (alkaline earth metal)
Yttrium (transition metal)
Zirconium (transition metal)
Niobium (transition metal)
Molybdenum (transition metal)
Technetium (transition metal)
Ruthenium (transition metal)
Rhodium (transition metal)
Palladium (transition metal)
Silver (transition metal)
Cadmium (transition metal)
Indium (post-transition metal)
Tin (post-transition metal)
Antimony (metalloid)
Tellurium (metalloid)
Iodine (diatomic nonmetal)
Xenon (noble gas)
Caesium (alkali metal)
Barium (alkaline earth metal)
Lanthanum (lanthanide)
Cerium (lanthanide)
Praseodymium (lanthanide)
Neodymium (lanthanide)
Promethium (lanthanide)
Samarium (lanthanide)
Europium (lanthanide)
Gadolinium (lanthanide)
Terbium (lanthanide)
Dysprosium (lanthanide)
Holmium (lanthanide)
Erbium (lanthanide)
Thulium (lanthanide)
Ytterbium (lanthanide)
Lutetium (lanthanide)
Hafnium (transition metal)
Tantalum (transition metal)
Tungsten (transition metal)
Rhenium (transition metal)
Osmium (transition metal)
Iridium (transition metal)
Platinum (transition metal)
Gold (transition metal)
Mercury (transition metal)
Thallium (post-transition metal)
Lead (post-transition metal)
Bismuth (post-transition metal)
Polonium (post-transition metal)
Astatine (metalloid)
Radon (noble gas)
Francium (alkali metal)
Radium (alkaline earth metal)
Actinium (actinide)
Thorium (actinide)
Protactinium (actinide)
Uranium (actinide)
Neptunium (actinide)
Plutonium (actinide)
Americium (actinide)
Curium (actinide)
Berkelium (actinide)
Californium (actinide)
Einsteinium (actinide)
Fermium (actinide)
Mendelevium (actinide)
Nobelium (actinide)
Lawrencium (actinide)
Rutherfordium (transition metal)
Dubnium (transition metal)
Seaborgium (transition metal)
Bohrium (transition metal)
Hassium (transition metal)
Meitnerium (unknown chemical properties)
Darmstadtium (unknown chemical properties)
Roentgenium (unknown chemical properties)
Copernicium (transition metal)
Ununtrium (unknown chemical properties)
Flerovium (post-transition metal)
Ununpentium (unknown chemical properties)
Livermorium (unknown chemical properties)
Ununseptium (unknown chemical properties)
Ununoctium (unknown chemical properties)

Currently, only pre-known groups, categories, and the element-self page can be marked this way. And only in the micro PT (!). After expanding the options

  • We can point each and every element for marking. Just list them like |mark=1,15,21,33.
  • We are not limited to categories or groups. Any range of elements is accepted. This can be used for any overlapping area. As the example shows: showing group 13 & cat colors (this is a big feature in the concept: we are not limited to a single dimension like "category").
  • Expect that the inner borders will not show (the outline remains).
  • Applied to every PT, in every size (while respecting current occurrence-borders).
  • Disjointed, scattered areas? Yes. (I'm a Tetris level 5+ gamer).
  • Option for a second marker (dotted border) for whenever needed.
  • Also: mark the s-block in a category-colored PT? Yes. Mark the Ln's, with the discussed ones apart (dotted), while a category is colored REM: yes.

Saves us from having to pre-define any mixing, any striping. Discussion on what to "mix", and on which page, in which detail -- all becomes more of a content discussion (not a question of how to squeeze it wikitechnically into PT).

Will not be available in 2013. -DePiep (talk) 07:51, 21 November 2013 (UTC)

Near-metalloids again

  • I wonder why people so eagerly mark carbon as "just a (typical) nonmetal" when many of its properties are in clear conflict with typical nonmetal traits: it remains solid at extremely high temperatures have thermal conductivity on the range of metals (both diamond and graphite), is vey hard and dense (relatively, to its atomic number) as diamond and well electrical conductive and metal-like looking as graphite. These properties are too alien for a pure nonmetal. There are things such as graphite foils (metal-looking elastic material), expanded (flexible) graphite or thin nanotube threads. Even very light, volatile oxides (gases at STP) are not so soluble and acidic.
  • Phosphorus is commonly known as a white, low-melitng and low-conducting soft substance, not so dense and very toxic, red (more metalloidal polymeric allotrope) is also well-known. Black, metalloidal, most stable allotrope is not, but its properties are more interesting - rather metalloidal than nonmetallic. Low (or just the lowest) electronegativity, in comparison to nonmetals, in almost all scales is also worth to note.
  • Selenium is not so metalloidal as it is often thought. It is well-conducting only in the light or (such as many other (rather) nonmetallic elements) under high pressure. Grey allotrope has good (even silverish(?)) appearance, its thermal conductivity is not so special (lower than its of black (metallic) phosphorus), it has relatively low melting and boiling point (in that it looks like heavier analogue of sulfur). Oxides are well soluble in water and signifiantly acidic, even its hydride is relatively strong acid.
  • Iodine looks really metalloidal (quite bright grey color when pure, metallic luster). It is diatomic and volatile, quite heavy element (Z=53) It has better conductivities than sulfur. Iodine definately has some properties, which are atypical for a nonmetal. It is highly acidic (HI solution in water is very strong acid). Many iodides are soluble in water and do not decompose so easily (unlike carbides, phosphides, selenides, even sulfides).
  • Radon is (like hydrogen) strongly nonmetallic physically. But these two elements have the same electronegativity in the Pauling scale (2,2) and show marked cationic behaviour (noble gases could be also depreciated to other categories of nonmetals).

From these elements, C, Se and P are most metallic, next are: I, S, then H, Rn. (talk) 08:02, 18 November 2013 (UTC)

Hmm. The stripes are beginning to grow on me. I can see an advantage in that the underlying category is preserved, which covers off on one of DePiep's points. In this scheme I would probably unstripe S and just note its metallic attributes in its article. Also change post transition metals to poor metals since Al is not a post-transition metal, it's a pre-transition metal. The name of the category of other nonmetals is very bad. I think you could change that to reactive nonmetals since they are in comparison to the noble gases. As well, no need to keep halogens as a category, although we still keep it as a group name. Astatine I would leave as a metalloid, for now, until we have more evidence that it's a metal. Oh, keep the noble gases category. Sandbh (talk) 20:27, 18 November 2013 (UTC)
  • It is a pity that there is no stripping "transition metal + poor metal", which would be useful to describe "anionic" electronegative metals (Pt and Au), even Au and Ag might be classified as "half-poor". For Be there also should be stripping.
  • Maybe we should leave controversial astatine and element 118 as just elements with unknown properties?
  • Sulfur lies not so near to the typical metalloids, it has phosphorus, not a typical metalloid, on the left side (hydrogen has nothing), but H practically borders to the metal-nonmetal dividing line. Sulfur is tricky. It has lower electronegativity than iodine, higher boiling point as is polyatomic, can be even a polymer. Iodine is a volatile diatomic element with metalloidal appearance and much better conductivity than S. In fact, there are two (or even three) classed of poor nonmetals. First consists of C, P and Se and they are typical, polymeric near-metalloids. Second class (weaker general metallic character) consists of I, S and two "electropositive" gases: H and Rn. Difference between I and S is not so great! I, Rn, (H) are "positionally" near-metalloids, but S is then "near-near-metalloid" which has two near-metalloids at neighbours (P on the left and Se below). S is almost anomalously metallic! It should be diatomic such as its diatomic neighbors from the diagonal (N and Br), but can be very polyatomic (not so polyatomic as (near-)metalloids). Electronegativity of sulfur is also closer to values of near-metalloids (2,58 in Pauling scale). S has not markedly metallic allotrope. It is in agreement with its position in the periodic table. (talk) 22:22, 18 November 2013 (UTC)

Of course, the mixing would be applied to our newer PT with diatomic and polyatomic categories, right? This looks like an old one. -DePiep (talk) 01:19, 19 November 2013 (UTC)
IP (TCO?), please add how far you meant this to be an older version. Is that part of the proposal, or do we need a category transformation first? -DePiep (talk) 07:55, 19 November 2013 (UTC)
No, I don't think the IP is TCO. For one, TCO would never start a long talk about categorization. ;-) Double sharp (talk) 04:09, 20 November 2013 (UTC)
I think this is the old German PT template. So yes. But what about this:
No need for mixing!
I'm pretty sure that E118 is already at the metalloid point; I'm not sure if Rn is there yet.
My main issue is that there's no distinguishing from near metalloids coming from the metallic side (e.g. Bi, Cn) and those coming from the nonmetallic side (e.g. I, Rn). Double sharp (talk) 07:17, 19 November 2013 (UTC)
I'd be inclined to leave Rn as a noble gas, using the Au, Pt argument that these are still regarded as metals even though they can form stable mono anions. S as a near metalloid seems odd---the metallic properties are not obvious unlike C, P (black), Se and I. Not having near metalloids on the metal side is OK; we call them post-transition metals. Cn remains a potential issue. Sandbh (talk) 10:06, 19 November 2013 (UTC)
Updated per your feedback. Cn is indeed an issue, but we can afford to procrastinate on worrying about it. ;-)
(P.S. I'm in favour of counting black P as the main P allotrope, because it's the most stable, in case anyone doesn't known my position yet. Not doing so tends to obscure the trends due to the inconsistency of such a choice with the standard ones for the other nearby elements.) Double sharp (talk) 10:53, 19 November 2013 (UTC)

Oh come on, people.

You're talking about how to define stripees, but haven't shown they're needed in first place.

Stripees are not good. For pros maybe, but not for a general reader.

I'll question that, not because I don't believe it, but because the German WP used it. Why? They must have had their reasons. Did they discuss its adoption and later removal? (If you have the link, post it...) Double sharp (talk) 04:36, 20 November 2013 (UTC)

Many, many, many people, maybe half of them or even more are people who can rate astatine negatively just because it doesn't have the sodium astatide formula. If I were talking to a chem professor, I would mention those nuances. Not in a general table, ever.

TBH I kinda tuned out away from that feedback, simply because 33% of them are "give me something I could figure out with first-year chem knowledge", 33% clearly show that the reader hasn't actually read the article, 33% are well-intentioned but not actionable, and 1% are actually useful. (These aren't actual statistics.) So I'd say that most of it can safely be ignored... Double sharp (talk) 04:36, 20 November 2013 (UTC)

And remember, metalloids are already a transition class. Why have a transition class between a normal class and a transition class?

There is a solid reason for it. We already have polyatomic nonmetals as our current one. Double sharp (talk) 04:36, 20 November 2013 (UTC)

Most people don't even read table legends, in general, remember that.

They'll see our table doesn't look like the ones they're used to seeing, and I hope they'll read the legends. If not, we've lost them either way. Those who do read the legend, however, will benefit. Double sharp (talk) 04:36, 20 November 2013 (UTC)

It is a pity that there is no stripping "transition metal + poor metal" It's not. To get the point with aurides and stuff, you would need to knopw it in first place. Or have some real understanding in chemistry.

And shouldn't we help readers advance to having some? Double sharp (talk) 04:36, 20 November 2013 (UTC)

Most people think of aluminum as of a metal. Those who do normally think of it as one similar to gallium and indium rather than AMs or AEMs.

Sandbh already responded to this on the main talk page. Double sharp (talk) 04:36, 20 November 2013 (UTC)

Draw a general picture, don't go into details unless it is expected (for example, how about a near metalloid article? it could take some info from metalloid info, we could give it a few links in some of our articles and we could treat it as a group like platinum group metals).

Hmm. I think the split in the nonmetals is important enough to give a new category. If we want to draw a general picture, we can do your radical s/p/d/f-block classification. (If you don't already know, though, I really hate splitting the table by blocks. What does it mean chemically and physically. In general, not much.) Double sharp (talk) 04:36, 20 November 2013 (UTC)


That might work, with any nonmetal subcategories possibly being able to be explained in the nonmetal article. There are three concerns. 1. Group 12 metals may be d-block metals but they are not, on any reasonable grounds, transition metals. 2. If so, what do we call the group 12-16 metals, noting Al is not a post-transition metal (i.e. it is located before the TMs)? 3. if Al is included in this "metals that need help" club how do we keep beryllium out of it? Should we keep beryllium out of it? Sandbh (talk) 21:11, 19 November 2013 (UTC)
IMO it is a step backwards. Why suddenly remove all traces of a division among the nonmetals when one certainly exists? Even the old "other"/"halogen" had it, even though it wasn't a terribly good one. Now we have a reasonable one. Why get rid of it? And group 12 and Al are problematic again. Double sharp (talk) 01:38, 20 November 2013 (UTC)
It is in fact a step backward. Oddities such as C and Se ("half-metalloids") are again pulled to the category of "reactive nonmetals". It is not so precise classification. (talk) 08:19, 20 November 2013 (UTC)

We can go even further.

--R8R Gtrs (talk) 18:41, 19 November 2013 (UTC)

R8R, what are you trying to say? Whatever we do, any level of detail is chosen, even if unchanged.
If a new striping is needed, it will arrive somehow. Talk should be about whether mixing cats is needed, for which elements, which cats, is it 50/50, and so. Given continuous discussion (in/out of WP), the topic is valid. -DePiep (talk) 19:23, 19 November 2013 (UTC)
What I'm saying is, no striping should ever be needed. It makes things too complicated (not colored looks, the science behind it)
I'm just following the discussion as it is, but if you find my comment misplaced, please move it. (if you don't, don't)--R8R Gtrs (talk) 19:57, 19 November 2013 (UTC)

About third periodic table: "Near-metalloids" have too alien properties to just count them along with strong nonmetals. They are a class themselves. Carbon is closer to boron or silicon than to fluorine. Selenium is more similar to tellurium than to chlorine, phosphorus to arsenic than to oxygen. Iodine is poorer (volatile and diatomic) near-metalloid, radon and hydrogen also shows some non-nonmetallic properties in their chemistry. Sulfur is on the border of so-called "near-metalloids" and nonmetals.

Noble gases are a class of nonmetals. Idea of splitting to reactive nonmetals and noble gases is poor.

I want to separate oddities such as carbon and selenium from strong, typical nonmetals. They just have too marked metallic properties, which are in contast of the general picture of a nonmetal (but nonmetallic character is still greater than metallic). Sometimes (by using metal-nonmetal dividing line) even more metallic elements (B, Si, As, Te, At) are counted as nonmetals.

Yes, near-metalloids have many contrasts with typical nonmetals. They have significant, sometimes even astonishing, metalloidal traits. In the case of C and Se it is mostly pronounced, in the case of P they are less known because of common contact with more nonmetallic, less stable allotropes. Just to rule out these strangers from the group of nonmetals and name they as "near-metalloids". (talk) 08:14, 20 November 2013 (UTC) (talk) 23:08, 19 November 2013 (UTC)

"Near-metalloids" in the third PT? -DePiep (talk) 23:19, 19 November 2013 (UTC)
(explaining) ... or the second PT here (by Ds Nov 18, introducing the word "near-metalloid"), not R8R's -DePiep (talk) 05:52, 20 November 2013 (UTC)
Did you know that one of the reasons I supported our current colouring is because polyatomicity/diatomicity correlates pretty well with metallic character? ;-) That's why I like your categorization so much, I think...
There are some issues about metallicity of polyatomic and diatomic nonmetals. The largest is the course of sulfur and iodine. Sulfur is polyatomic (usually oligomeric in the form of S8), but does not have a "metallic" allotrope at STP. Catenated, plastic sulfur is closer to metalloids, but is far less stable. Iodine is diatomic, but in its pure form looks just metallic grey and is a better conductor than sulfur. Iodine appear to be more near-metalloidal than sulfur due to its appearance and conductivity. Hydrogen is diatomic, physically is a good nonmetal, but chemically is markedly metalloidal. (talk) 07:59, 20 November 2013 (UTC)
I still think we should split noble gases. They are not reactive nonmetals and have fairly distinct properties, such as general nonreactivity. (Not so Rn: apparently it can react with a few exotic compounds at room temperature, which Xe can't do!) I think they form the other extreme of nonmetallic properties (that isn't the near meatlloids). Double sharp (talk) 01:38, 20 November 2013 (UTC)
Radon is not so nonmetallic (low electronegativity, cationic chemistry). It looks rather as a form of near-metalloid. (talk) 08:08, 20 November 2013 (UTC)
Hmm. OTOH it does have the extremely small liquid range and high volatility commonly associated with noble gases. Its main claim to metallicity is, as you observe, its markedly low electronegativity and showing of some cationic behaviour. I am not sure if this is enough to bring it out of the noble gases. It is certainly already more of an ignoble gas, willing to react at room temperature, if only with weird compounds like [O2]+[SbF6]. I am still not completely convinced that the change happens between Xe and Rn; I'm more convinced by a change between Rn and E118. Double sharp (talk) 10:23, 20 November 2013 (UTC)

I am talking (in fact) about the lack of near-metalloids in third periodic table on this page. Many properties of near-metalloids are worth to mark. They can for example: have very high melting, boiling or sublimation points, be very hard, really well conductive, look metal-like, be good semiconductors. (talk) 23:25, 19 November 2013 (UTC)

I promise you to explain you my point of view on this (I have notoriously read what you had written in this page first, yes.) when I have some time, okay?--R8R Gtrs (talk) 19:14, 5 December 2013 (UTC)

Al is a poor metal (and implications for near-metalloids)

I'm now satisifed(!) that aluminium does qualify as a poor metal, whereas beryllium doesn't. A poor metal is a physically weak metal that shows significant nonmetallic chemistry. Beryllium and aluminium both show significant nonmetallic chemistry. However beryllium is pretty strong whereas aluminium isn't. Here are some unattributed snippets from Google Books illustrating the difference:

'Pure aluminium is a comparatively weak metal…
'Aluminium is a light but relatively weak metal…'
'Pure aluminium is rather a weak metal…'
'Beryllium is a relatively light yet strong metal'
'Beryllium is a strong metal, which is lightweight, resistant to corrosion and melts at a very high temperature.'
'Be is a light, strong metal with a very high melting point…'

There are plenty more like that.

In conclusion, and as I see it: Be = alkaline earth; Al = poor; Group 3 (Sc, Y, Lu, Lr) = marginal TMs; La–Yb = lanthanides; Ac–No = actinides. We keep the alkali metal and alkaline earth categories. Further distinctions as to the non-metallic character of metals (e.g. Au) or the metallic character of nonmetals (e.g. H, C, Se) can be made in the articles for the respective elements. I think the rare earths are better regarded as an uber-category comprising the first three members of group 3 + the lanthanides.

With respect, if the IP editors want to make a case for a different categorisation scheme that includes e.g. near metalloids then they need to do a write up that (a) satisfies the YBG rules; and (b) is fully referenced, as per the current nonmetal article. The YBG rules are that any new categorisation scheme be clear ('The criterion for division should be easily explained'); unambiguous ('It should be relatively obvious which category each element fits into'); and meaningful ('The categories should have significance more than just dividing for the sake of dividing. There should be enough within-group similarity and enough between-group dissimilarity so that each group could be the subject of a separate encyclopaedia article.'). Sandbh (talk) 12:03, 20 November 2013 (UTC)

Why are Lu and Lr not lanthanides and actinides in this scheme? Chemically they surely are.
As I see it, the main stumbling block for the categorization in the second PT on this page (mine, based on the IP's; shall we call it "option 18"? :-P) is how to define "near metalloid" and "typical nonmetal". The former can be thus "a nonmetal with many markedly metallic properties, but not yet at the metalloid threshold" while the latter would be rather self-explanatory. But now I'm thinking that polyatomic/diatomic option 10 actually works very well (I being on the threshold of being polyatomic, with S having weaker metallic properties that correlates with its being farther from the metalloid line).
Agree on Al: we must have a strict definition. Al fits it; Be, not so much (MH 5.5). Double sharp (talk) 02:15, 21 November 2013 (UTC)
Again about German Wikipedia. Now it is just stupidity - selenium as a metalloid and carbon and phosphorus as a non-metals. Carbon is in many ways more metallic than selenium. Its "metallic" (more precisely, metalloidal) character is too underestimated, especially in comparison to selenium. Phosphorus is next near-metalloid which should be in the one group. I looks generally closer to C, P, Se than S, mainly because of appearance and conductivity and its position in the periodic table. In the name of the class for C, Se, P the name "metalloid" should be, not nonmetal. Errors about classification of these elements are often to blatant, selenium is even called a "non-ferrous metal". Carbon looks very oddly in the only-nonmetal group with its melting point, conductivity, appearance, some properties of diamond or nanotubes. Name of carbon ends at -on, such as boron and silicon (these three elements can be very hard and have the highest melting and boiling points (for B and Si sometimes values about 2500 C are met) in main gropus). Diamond, boron and glassy carbon are really hard materials (7 - 10 Mohs), unlike typical nonmetals. Thus, carbon is definately halfly (not fully) metalloidal. Selenium also (mainly due to the other reasons - apperance of grey Se and photoconductivity), but halfly, not fully metalloidal. Half-metalloidal character of phosphorus is usually hidden due to popular presence of less metallic allotropes, especially white one. (talk) 17:35, 20 November 2013 (UTC)

And now for the predicted elements again

The chief ones we need to worry about are E117 and E118. (E171 is treading on dangerous ground, assuming based on properties similar to I2 that it would form (171)2, but I think we've sorted that one out. And E172 is a very good noble gas, though it's probably actually a noble liquid or solid.) IP, I want your comments, please... ;-)

I've given quotes from Fricke below, to supplement the material from the articles (ununseptium, ununoctium, period 9 element).

Element 117

(Fricke 1974) "Element 117. (eka-astatine) is expected to have little similarity to what one usually calls a halogen, mainly because its electron affinity will be very small. Cunningham (96) predicted its value as 2.6 eV, whereas the calculations of Waber, Cromer and Liberman (54) gave a value of only 1.8 eV. As a result of this small electron affinity, and from extrapolations of the chemical properties of the lighter halogen homologs, all authors agree that the +3 oxidation state should be at least as important as the −1 state, and possibly more so. To take an example, element 117 might resemble Au(+3) in its ion-exchange behavior with halide media. Cunningham (96) describes the solid element 117 as having a semimetallic appearence."

(1971) "Occupation of the 7p3/2 subshell begins at Z = 115 with a binding energy which is only half as large as that of the 7p1/2 electrons, so that the elements E115, E116 and E117 will have +1, +2 and +3, respective1y, as their normal oxidation state. The higher oxidation states will be possible only in the presence of strong oxidizers. An interesting question is whether element E117 which is in the chemical group of the halogens would form the -1 anion. Cunningham predicted a electron affinity of 2.6 eV whereas the calculations of Waber, Cromer and Liberman calculated a value of only 1.8 eV. Cunningham describes the solid element El17 to have a semi-metallic appearance. It should form stable oxyions of the (III), (V), and (VII) states and stable interhalogen compounds. Because of the small electron affinity it might not exhibit the -1 oxidation state, which is even further suggested by the smaller value calculated by Waber et al. Certainly it will be a very soft base compared with fluoride or chloride which have a electron affinity of 4 eV resp. 3 eV."

Element 118

(Fricke 1974) "A. V. Grosse wrote a prophetie article (95) in 1965 before the nuclear theorists began to publish their findings concerning the island of stability. In this paper he gave detailed predictions of the physical and chemieal properties of element 118 (eka-radon), the next rare gas. He pointed out that eka-radon would be the most electropositive of the rare gases. In addition to the oxides and fluorides shown by Kr and Xe, he predicted that 118 would be likely to form a noble gas-chlorine bond. These very first extrapolations into the region of superheavy elements have been fully confirmed by the calculations, because the first ionization potentials turn out to be much lower than in all the other noble gases. Independently Grosse (95) and Cunningham (96) found that the expected boiling point of liquid element 118 is about −15 °C, so that it will be nearly a "noble fluid". Because of its large atornic number it will, of course, be much denser than all the other noble gases. But, in general, the chemical behavior of element 118 will be more like that of a normal element, with many possible oxidation states like +2 and +4; +6 will be less important because of the strang binding of the p1/2 electrons. It will continue the trend towards chernical reactivity first observed in xenon."

(1971) "The "noble gas" at Z = 118 will be a very weak noble gas in the sense of He and Ar but as well in comparison to Xe and Rn. The ionization energy is so small that normal covalent bondings are expected with oxidation states of 4 and 6. The extrapolation of Cunningham [35] expects a boiling point of −15 °C so that it will be nearly a "noble fluid"..."

(1971) "Previous analysis by Waber, following an informal discussion with Fano, indicated that negative ions of the noble gases would have configurations such as np5 (n + 1)s2. The spectra of such species have been found at the National Bureau of Standards following electron bombardment of the noble gases. It would be expected that E118 could readily form such anions. Calculations have not confirmed the likelihood of such species. Independently Grosse and Cunningham found that the expected boiling point of liquid E1l8 is about -15°C, so that it will be nearly a "noble fluid". It might be predicted as well that the crystalline form would be much denser than the other noble gases. That is, the bonding in solid E118 would be stronger than given by van der Waals forces. These predictions from systematic continuation are supported by the calculation. Its first ionization energy is small, only 9 eV, and the strongly split p shell giving rise to frontier orbitals at the surface of the atom suggest that E118 will be more a normal element with many possible compounds than a noble element. Thus it will continue the trend towards chemical reactivity first observed in xenon."

Element 171

(Fricke 1974; he says almost exactly the same thing in the other papers) "Element 171 is expected to have many possible oxidation states between −1 and +7, as the halogens do. Here again, the electron affinity will be high enough to form a hydrogen halide like H(171). Fricke et al. (56) calculated a value for the electron affinity of 3.0 eV, which is as high as the value of I, so that (171) will be quite a soft base."

Element 172

(Fricke 1974; ditto) "Element 172 will be a noble gas with a closed p shell outside. The ionization energy of this element, as shown in Fig. 15, is very near to the value of Xe, so that it might be quite similar to this element. The only great difference between Xe and 172 is that element 172 is expected to be a liquid or even a solid at normal temperatures because of its large atomic weight. As indicated in connection with the noble gas 118, element 172 will tend to be a strong Lewis acid and hence compounds with F and O are expected, as has been demonstrated for xenon."

Double sharp (talk) 12:45, 21 November 2013 (UTC)

Element 85 (At, astatine) is now predicted to have metal band structure at normal conditions. E117 probably also will be a metal, what about E171 - I don't know, but it (for me) can also be a metal with high electron affinity, electronegativity and first ionisation energy.

What about apperance, volatility and conductivity of E118 and E172? Are they nonmetals, metalloids or even metals? It is really interesting, because, according to digonal trends, they should be at least metalloids. (talk) 15:11, 21 November 2013 (UTC)

Still feeling doubtful over a metallic E171. Here relativistic effects make period 9 similar to period 3 as the subshell splitting cancels itself out (9p1/2 ~ 8p3/2 in energy). So halogenic E171 is plausible, and the argument doesn't depend on At, whereas E117's does. He expects it to be a soft base like I; so I think it would be a nonmetal, though with near metalloidal tendencies, like iodine. Still H(171) is stated to be a hydrogen halide, and not a halogen hydride like AtH; thus I think E171 is not yet a complete metalloid. That's my main argument. I don't think hydrogen auride is known, yes? Or else I would probably change my mind quickly.
No idea about appearance, but I think that E118 would from here be a rather typical nonmetal (if a reactive noble gas can be considered typical!). E172 though has relativistic effects conspiring for a period-3-like shell closure, so that it should be a good noble gas per Fricke, somewhat like Xe. So I think it should be inert, volatile and not conductive. E118 should be very much more reactive, and because (118)F2 and (118)F4 are expected to be ionic compounds (E118 is highly electropositive), I expect much better conductivity than the other noble gases. Double sharp (talk) 06:45, 22 November 2013 (UTC)
It seems presumptuous to try to group unnamed elements with speculative arguments. Articles on individual elements could outline such reasoning, but this should not extend to the periodic table template. Using light grey to indicate that there is insufficient experimental data to categorize these elements is accurate and straightforward. Bcharles (talk) 17:02, 14 June 2014 (UTC)
I agree with you when it comes to known elements (up to 118); since there is known info, we should make it clear that there is insufficient experimental data to categorize them. But for elements beyond 118 nothing is known: and colouring every single element beyond 108 light gray in the extended periodic table makes it seem to me to be of somewhat doubtful utility, as it is after all meant to be a prediction from reliable sources. Double sharp (talk) 06:10, 11 July 2014 (UTC)


Near-metalloids (elements with general properties between metalloids and nonmetals) in the periodic table
H   He
Li Be B C N O F Ne
Na Mg Al Si P S Cl Ar
K Ca Zn Ga Ge As Se Br Kr
Rb Sr Cd In Sn Sb Te I Xe
Cs Ba Hg Tl Pb Bi Po At Rn
Fr Ra Cn Uut Fl Uup Lv Uus Uuo
Periodic table groups 1, 2, and 12 through 18:
  Typical nonmetallic near-metalloids.
  Less typical nonmetallic near-metalloid.
  Elements with overall metallic properties between nonmetallic near-metalloids and more typical nonmetals.

It looks that some metalloidal chaaracter of hydrogen and carbon is really important for life. Water should be a gas, but has the relatively very low volatility quotient for a nonmetal oxide (10 protons and boiling point 373 K - about 37,5). Low electronegativity of hydrogen is really important. Carbon can form very stable very long chains, also at normal conditions. Typical nonmetals are oligomeric (polymeric sulfur is not so stable at normal conditions, most polymeric nonmetals are C, P and Se - typical near-metalloids).

Diamond is not so clearly nonmetallic. It has some properties of a metalloid (such as thermal conductivity, polymeric three-dimensional structure (like Si and Ge, even white Sn), extreme hardness, very high density (it has very low atomic number, but (anything?) in third period has significantly lower density) and some of a nonmetal (wide band gap makes it colorless and electrically non-conducting). It is itself near-metalloid. Fullerenes are another near-metalloidal allotrope (C60 is quite lustrous and has electrical conductivity and band gap similar to boron at normal conditions), but not metalloidal (they are like noble gas - relative volatility is very high, opposite to diamond and graphite), are not so much olygomeric (have larger number of atoms in molecule than P4, S8 and Se8, even some metalloids can form (not very stable) oligomers at low temperatures (As4, Sb4)). Polymeric allotropes (such as graphite and grey Se) tend to be more metallic than oligomeric.

Iodine is very oligomeric (diatomic) at STP. It is not so metalloidal property, but I2 looks metalloidal (quite bright grey when pure) and has much higher conductivity than more polyatomic sulfur.

It would be very curious if astatine can form diatomic (highly stable) and metallic (band structure!) allotrope at STP. It is probable that usually given boiling point of astatine is boiling point of diatomic allotrope, metal should not have so narrow liquid range.

C, P, S are "half-metalloids" (these elements have very stable polymeric, metal-like looking, relatively conductive allotropes), I (has metal-looking allotrope but volatile, diatomic and less conductive than "metallic" forms of C, P, Se), S, H, Rn are "quarter-metalloids". — Preceding unsigned comment added by (talk) 21:59, 23 November 2013 (UTC) (talk) 22:58, 21 November 2013 (UTC)

S, H, I, Rn are greater issue in the case of the level of metallicity than C, P, Se. It is hard to say which of these earlier four element is the most metallic.

Sulfur is olygomeric (S8), but C, Se and P not. It is also interesting what about carbon - there are calculations which say that less metallic carbyne (with band gap over 3 eV) is more thermodynamically stable than metalloidal graphite. Diamond is very stable, but less stable than graphite. In addition, carbon (not sulfur) has the largest number of allotropes and its allotropes can really dramatically differ.

What about fullerene C20? Is it polymeric or monomeric? Is it a gas at STP or at least a liquid? What is most oligomeric stable form of carbon? Can forms such as atomic (not metallic) carbon, C2, C3, C4, C5, C6, C7, C8, C9, C10 be stable and not to polymerize? Many properties of graphite, nanotubes or even diamond definately rule carbon out of "just nonmetallic" group of elements and move it to a group of typical half-metalloids.

Carbon, phosphorus, selenium and metalloids are polymeric elements, sulfur is rather oligomeric.

Cow city (talk) 22:40, 23 November 2013 (UTC)

C, P and Se are rather "metalloids with advantage of nonmetallic properties" than "nonmetals".

There are also typical metalloids (B, Si, As, Te) and metalloids with advantage of metallic properties (Ge, Sb).

I don't think that naming carbon or selenium a metalloid is an error. But aluminium should not be named as metalloid, mainly because of its band structure. (talk) 11:58, 25 November 2013 (UTC)

But classifying only selenium as a metalloid is certainly an (very popular) error. We should specially pay attention on it.

Carbon with its melting point looks really "stupid" between "just nonmetals". Phosphorus or selenium have far much more (above 3000 K lower) melting points. (talk) 14:09, 27 November 2013 (UTC)

I think C, P (black, just for clarity), and Se are the main representatives of the near metalloid category. The others are weaker and have less claim to it.
But given that this is just the carbon diagonal – including I with a metallic appearance and almost being a polyatomic nonmetal, and Rn with chemical near-ignobility and cationic chemistry utterly uncharacteristic of a classical neon-like noble gas – I have to wonder if it is worth marking as a separate category. From periodic trends, and the position of the metalloid line, we can immediately guess that these elements are going to be predominantly nonmetallic with markèd metallic properties (especially those right next to the metalloid line), just as we can do likewise for the hypothesis that the poor metals are going to be predominantly metallic with markèd nonmetallic properties. Does this category tell us much of anything new about the elements involved? Polyatomicity vs. diatomicity vs. monoatomicity does tell us information about the elements' metallic character and behaviour (we're all agreed, I think, that a more-metallic-nonmetal vs. less-metallic-nonmetal division exists and is important enough to split the category); this isn't immediately obvious from a first glance at the periodic table (nitrogen, sulfur, bromine, and xenon are in the same diagonal; yet S is far more of a near metalloid than any of the other three). In other words, is this proposed categorization really that much more meaningful holistically than our current one (dubbed "option 10")? Double sharp (talk) 14:53, 28 November 2013 (UTC)
P.S. Why is an anomalous melting point a non-issue when it comes to letting the noble gases into the nonmetals category, as you proposed (due to the London dispersion force being the main IMF), and yet it is absolutely prohibitive for carbon's memborship into the very same category?
(If I come off as too harsh and dismissive of your proposed categorization, I apologize; that is absolutely not my intent. I just want to look at it objectively and weigh its strengths and weaknesses with regards to the possible alternatives.) Double sharp (talk) 14:56, 28 November 2013 (UTC)

I think that C, P and Se may be even vieved as "metalloids closer to nonmetals", when B, Si, As, Te are "typical metalloids" and Ge and Sb are "metalloids closer to metals". All most stable forms at STP form of metalloids are semiconductor or semimetals and polymers with higher melting points than nonmetals. They have shades of grey and metallic luster.

Sulfur is an anomaly. It should be only diatomic due to its position in PT. What about metallic sulfur chains inside nanotubes?

Carbon (even colorless insulating diamond) looks funny inside nonmetals in its melting point about 3900 K. However, it (probably) is totally unable to form C-O-C-O-C-O... chains at STP. It has a mixture properties of a metalloid and a nonmetal ("half-boron" and "half-nitrogen", BN is practically "inorganic carbon"), therefore is not an "only-nonmetal". Situation of P and Se is very similar, but their metalloidal properties can be other due to larger size of the atom and higher weight of their atoms. H and Rn are very electropositive gases with marked cationic chemistry.

All solid at STP "nonmetals" are not so good examples of nonmetals not because of their state of matter at STP, but their metal-like apperance and polymeric structure. Metalloids are polymers with not true metallic band structure at STP (semiconductor or semimetal), such as typical near-metalloids (which also can be achieved as quite conductive metal-like looking solids known as graphite, black phosphorus nd grey selenium). Metal-looking graphite is rare, usually we see almost black dull powder or microcrystalline form of it. Black P is very unpopular, grey Se is the most "admired" near-metalloid. Iodine is poor conductor and volatile, but also has a luster and is even quite bright is its pure form.

There is not a staircase between metalloids and nonmetals, but rather a straight diagonal (C, P, Se are half-metalloids and half-nonmetals).

Diatomic and polyatomic nonmetals classification tells us not about summaric metallic properties, but mainly about structure of elements with more traits of nonmetals than metals. Some of them are in fact halfly metalloidal and halfly nonmetallic and these elements are also more typical "near-metalloids" (or just "weak metalloids") than some others (C, P, Se vs H, S, I, Rn).

Maybe it is the time to "kick off" "weird" elements from the small group of nonmetals?

Diagonals and stripping would be better than clssification with diatomic and polyatomic nonmetals. New class "near-metalloids" looks even better than them. And for H, S, I, Rn should be stripping or diagonal near-metalloid - nonmetal. Weaker elements with advantage of nonmetallic traits (C, P, Se; H, S, I, Rn) will then be separated from "strong" nonmetals (He, N, O, F, Ne, Cl, Ar, Br, Kr, Xe). (talk) 02:42, 2 December 2013 (UTC)

Again: carbon, phosphorus and selenium are not just nonmetals. They are suspiciously "metallic". First two elements are really rare seen in their shiny forms.

The substance (named at the page as "black phosphorus") looks like a grey metalloid with strong luster, even not black (on the page

Here is a picture of greyish-black "flexible graphite" with quite strong metallic luster: — Preceding unsigned comment added by (talk) 17:51, 4 December 2013 (UTC)

The division sure as hell exists

I prefer to think it's a gradient from metals to hardcore nonmetals, but it doesn't matter.

Try to think of it in a different way (I did try your way of thinking about it before asking you to, of course, and still think you could use another perspective, so please do).

We can build a descriptive model of all elements with just three categories: metals, reactive nonmetals, and noble gases. It is an approximate model, but it can work. Just when describing the p block, you will have to mention antimony has a few characristics that are more nonmetallic than metallic, but is more of a metal than of a nonmetal if you consider the overall score. It was, in fact, taught to me in school. This model does work. It is simple. In the beginning, I t makes you think, "Aha, that's who it works, I get it." Seems we can make a more accurate version, though.

And there appears the concept of metalloids, the elements for which you had to do these remarks (e.g. begins to be nonmetallic). It is, in fact, a popular concept now. It avoids these remarks, shows the transition from metals to nonmetals to be smoother than just a cracking line between those metals and nonmetals, there's a buffer zone now. Works even better at the cost of simplicity and "gettability." Still not too complicated.

Now when you have metalloids, things are crazy. People can't agree on selenium. At the same point, you think, hey, we'll use a buffer then, put Se there. And hey, P would fit in. And I! C! (Maybe you got this idea in first place in some different way, it doesn't matter) Maybe. But having this category makes things crazier.

First of all, if I were shown the table as you propose it, say, five yrs ago, I wouldn't get the point. Which is a very very very very very major aspect. (Of course, it's not about me, it's about readers. Actually, most our readers are not specialists in the topic they read about. They wouldn't get the point. Which is sad. Wiki is for common people, that is the point for the whole thing.)

Seriously, the way you suggest to have it is scientifically legal. No question of that. But this is kinda pro level.

When you come to school at the age of seven, they don't make you solve differential equations. They teach you to subtract, multiply, count apples. 2 + 1 = 1 + 2, but the trick wouldn't do with subtraction. You have to know that (and a lot of other stuff) to get to differential equations. Otherwise, it would be just mambo jambo you would want to run away from.

Same thing here. A majority of readers would not know why you grouped it this way. Here, in Wiki, that is. If you were writing a specialized book or an article about the topic, and be sure it would be read by acknowledged people, you can include that pro level.

You understand the topic now, but hopefully that would not prevent you from trying to wear a pair of a dummy's shoes for this occasion.

If even they can't agree on Se. It is an issue, yes. But altogether with graphite seminonmetalicity, it's still the lesser of two evils.

Wiki, in a nutshell, is a place existing established data is represented. The term "near metalloid" (or any other I tried) is not common for Google. It is not obvious for most readers (not guys who understand how things are going on like you, of course), either. Again, the classification is legal elsewhere, in a place establishedness is not required.

Tl;dr It is a good classification for some purposes, but reader won't get it.--R8R Gtrs (talk) 21:17, 12 December 2013 (UTC)

(P.S. There are other issues like metal near metalloids(?), gold, etc., but I consider the argument above much more important than all of those ones. Wiki is reader-oriented. It's not a place to install a new truth, however true it is. That's the whole point of Wiki.)

(P.P.S. I skipped the regular grammar check when writing this, because of the lack of time to spend here. Sorry if the text is too difficult to read. Hope it's not, though.)

  • I definately do not accept classifications in which Se is classified as a metalloid and C as just nonmetal (P then has to be also pulled to not-only-nonmetal category). Graphite has much more abnormal (in fact, totally abnormal for a nonmetal) melting point and boiling point (rather sublimation point) than Se, Se has lower thermal conductivity.
  • When somebody names Se a metalloid, he just has to name C also as a metalloid. It he does not do it, he makes an error and inadequate classification. P is too similar to Se and C and has to be pulled into the category in which C and Se are.

If even they can't agree on Se. It is an issue, yes. But altogether with graphite seminonmetalicity, it's still the lesser of two evils. I do not agree with this opinion if it tells that Se is more metallic than Se. For me C is on the same level of metallicity as Se, maybe even a bit higher (of course, Se is more metallic in some classifications, but let's look also at P). And what about (black) P? It is also a "ner-metalloid". Typical near-metalloids are closer to typical metalloids than to typical nonmetals, they are not near-nonmetals. C, P nd overclassified Se have advantage of nonmetllic traits. Diamond is not so clearly nonmetallic as it is popularily thought. Structure, thermal conductivity, hardness, "desolidification" point are typically metalloidal (are such as Si and Ge, even not such as Se and P), but its appearance and electrical conductivity are nonmetallic (which is consistent with its position in the periodic table). In addition, graphite ("grey" or "metallic" carbon), black (grey, metallic) P and grey (metallic) Se are just (weaker than typical) metalloids itself (this classification does not include chemical properties of the elements and other allotropes), not nonmetals. (talk) 21:45, 12 December 2013 (UTC)

Now when you have metalloids, things are crazy. People can't agree on selenium. At the same point, you think, hey, we'll use a buffer then, put Se there. And hey, P would fit in. And I! C! (Maybe you got this idea in first place in some different way, it doesn't matter) Maybe. But having this category makes things crazier.

I tink that metalloid category is useful to describe transition between metals and "nonmetals". Metallic "near-metalloids" (metals which are weak chemically and also physically) are named as poor metals (this name is also problematic). Nonmetallic near-metalloids can be polyatomic, diatomic and monoatomic, but the most typical (C, Se, P) are the most polyatomic of them. Diatomic I looks like a metalloid, but it can be the most metallic property of this element. H and Rn are very electropositive nonmetals and have marked cationic chemistry, it makes them flawed, not typical nonmetals. Metalloids tend to have EN about 2, near metalloids about 2,25 (H, P, Rn) - 2,5 (C, Se, S, I) and nonmetals about 3 (such as N, Cl, Br) and lower - O, F (Xe also has rather low - 2,6 in revised Pauling scale).

Nonmetal should not be polymeric, too conductive electrically or thermally, should not have metallic luster. Typical near-metalloids do something opposite - they are grey, metal-like-looking polymers with quite good conductivities, narrow baand gaps and rather high "desolidification" point (it is especially true for C).

There is no "staircase" which divides metalloids and nonmetals, but rather a diagonal - C, P, Se are half-metalloids and half-nonmetals than nonmetals. S can be also an issue - "Conducting linear chains of sulphur inside carbon nanotubes". Is there polymeric iodine allotrope? — Preceding unsigned comment added by (talk) 22:08, 12 December 2013 (UTC)

Selenium is the large issue. Is it a nonmetal or a metalloid? Why only nonmetqallicity of selenium is questioned so often and not nonmetallicity of carbon and phosphorus? Iodine is less problematic, but in many properties closer to C, P, Se than to typical nonmetals. Sulfur also. All solid nonmetals are defective. They have stable lustrous and (or) are polyatomic. In almost all electronegaivity scales P has the lowest electronegativity from all nonmetals, lower than Se, which is closer to S and C, not to P. Why selenium is marked as a metalloid and P not? I think that it is unjust. Phosphorus pentoxide, sulfur dioxide, sulfur trioxide, selenium dioxide, selenium trioxide are more soluble and more acidic than oxides of carbon (carbon monoxide and carbon dioxide). PCl5 and SeCl4 have very similar sublimation points. Phosphorus (V) oxide (especially polymeric forms) and selenium (IV) oxide can have quite large desolidification point. Se has qiute large reflectance about 30% - average (, but Te has about 2 times larger than Se - about 60% ( graphite about 2 times lower than Se - ca. 15% (, As has about 50 - 51% ( What about black phosphorus, boron (grey allotrope) and iodine?

Se has lower first ionisation energy than P and even As, S has is also lower than P. But the sum of first three ionisation energies is a bit lower in the case of phosphorus, not selenium. Tellurium has lower sum of first three IEs than P, unlike S and Se.

Carbon is weak chemically, it forms monomers with other nonmetals, such as N, O, S, Se, unlike metalloids. It is significant nonmetallic property. It has large ionisation energies and electronegativity. Physically it looks much more like polymeric, in fact quite conductive boron than highly nonmetallic nitrogen, but not chemically (rather opposite due to the formation of monomeric "nonmetallides"). B has a deficit of electrons, C not. And atom of C is small and light, P is heavier and larger, atom of Se is definately the largest of the atoms of four polyatomic nonmetals (C, P, Se). Although P has lower electronegativity, Se forms tetrameric tetrachloride, just like Te. It is an overlap. Se should be more metallic than S due to periodic laws. Some attributes should be shared with Te, but many should not and are not shared. Sometimes properties of Se are intermediate between properties of S and Te. SO2 and SeO2 are soluble in water, unlike TeO2. But H2SeO3 has lower pKa than sulfur analog, it is has pKa rather between pKa of H2CO3 (weaker) and H2SO3 (stronger). Volatility of SeO2 is between volatilities of S and Te analogs. H2Te is stronger acid than H2Se. But Se2Cl2 is low-melting and volatile. SeO3 is like SO3, not like TeO3, does H2TeO4 exist and what is its acid strength? SeF4 is rather monomeric, unlike TeF4. Electronegativity of Se is closer to its of S, not Te. Grey Se looks like a bit weaker version (lower mp and bp - diamond has larger mp and bp than Si and Ge; wider band gap, significantly lower reflectance) of grey Te. Se can be present as relatively stable olygomers such as Se8 (just as other typical near-metalloids), but I have not listened about sulfur-like olygomers of Te. Se and S forms volatile liquid compound with carbon (monomers), CTe2 (or better Te2C) is unknown. Carbon is an intermediate between B and N in general. P is more like As than N! It is also a near-metalloid, white allotrope is not the most stable, even red is not. Sublimation point of polymeric P is relatively similar to sulblimation point of metallic As. Electronegativity of P is much closer to As than its of N. Sulfur is also more similar to Se, not to O. Diagonals or strippings in the case of C, P, Se would be very useful and informing solutions - C, P and Se are intermediates between typical metalloids and nonmetals. They are "halfly metalloidal", which is the source of they marked metalloid properties, such as lustre, conductivity, polymerism, quite low electronegativities (especially in the case of P). Se is chemically and physically similar rather to P, not to Te and has to be classified in one metallicity class with P. (talk) 13:24, 14 December 2013 (UTC)

Sorry for making you wait for me. Short re for now, it's 4:30 AM here.
(The discussion will be a lot easier to read if you use indents. To use one, put a colon (:) in the beginning of every line (that is, after you press Enter. Multiple colons will result in an according number of indents :)
I did read your reply, and am a bit sorry to say I can't reply to it directly. My point is, (I think I found simpler words) the metalloids--"true" nonmetals buffer category is too much detail for a Wiki page. Really. It is not wrong (while doubtable if you're not familiar with things -- which is also a problem), but I wouldn't use it for the same reason we don't use, say, platinum group metals (a well-established term). The best you can do is to write the near metalloid article (why wouldn't you?) and see if other people get it. It can become a secondary group value for carbon and others. Notice that an article would have to comply with the WP:N guideline (I don't know if it does, too tired to check (four in the morning), please check. If it doesn't, then having it as a category, even a secondary one, is not a right thing for Wikipedia. Also note that ineligibility for Wiki doesn't mean ineligibility in general (Wiki is relatively close-minded down to its core, in its essence) or for any other place. (It is customary to Wiki, that a point of view, however right, should not be represented in Wiki if not supported by a sizable number of sources.)
IOW it doesn't really matter for Wiki (and not for anything else) if what you write is true (note I think it is), all that matters is sources, which you are very low at (Google Ngram viewer resulted in zero hits between 1500 and 2008 (which is the limit the machine can only work with) for "near metalloid").--R8R Gtrs (talk) 00:47, 27 December 2013 (UTC)