Wikipedia talk:WikiProject Elements

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Reclassifying the nonmetals

Reclassifying the nonmetals is the title of an original post here at WT:ELEMENTS by Sandbh, 12 March 2017. Long and large discussions followed, now in the archives. Below is the current status. -DePiep (talk) 22:30, 27 July 2017 (UTC)

Archived

• (part 1/n): /Archive 27 (Whole page) Original post and discussion
• (part 2/n): /Archive 28, continuation -DePiep (talk) 12:45, 13 August 2017 (UTC)
• (part 3/n): /Archive 29, naming the group of eleven: - YBG (talk) 05:42, 19 August 2017 (UTC)
• (part 4/n): Archive 29, Reclassifying the nonmetals: Another continuation (51k) - DePiep (talk) 13:55, 29 September 2017 (UTC)
• (part 5/n): Archive 30, Proposal; rfc preliminary notes (2k) - DePiep (talk) 13:55, 29 September 2017 (UTC)

Open (not archived yet)

• (part 6/n): #RfC: Replace categories of poly/diatomic nonmetal with less active/active nonmetal - YBG (talk) 01:48, 19 September 2017 (UTC)
• (part 7/n): #Long post re (gasp!) other nonmetals - Double sharp (talk) 06:41, 20 September 2017 (UTC)

Rare-earth metal: adjective

Recently, we can see edits (by Mikhail Ryazanov [1]) that change "rare earth metal" into "rare-earth metal". Grammarly correct I understand (rare is an adjective), but does it fit with our world view (iconic names)? -DePiep (talk) 22:23, 11 August 2017 (UTC)

The grammatically correct (hyphenated) version is used in reliable sources (for example), so I see no reason to use the wrong one here. Especially since, as the WP article mentions, "rare-earth elements" are actually not so rare, thus the hyphenated version is also less confusing. — Mikhail Ryazanov (talk) 23:12, 11 August 2017 (UTC)

Curiously, the IUPAC approved term is "rare earth metal". As our article notes, while they aren't especially rare they're typically dispersed and not often found concentrated in economically exploitable ore deposits, hence they are rare in that sense. It's interesting to see that the reliable source calls them "rare earths" elsewhere in the article. The Google Books Ngram viewer, here, shows that in 2008 "rare earth elements" was the most popular form by a 3:1 ratio. The 2008 ratio for rare earth metal to rare-earth metal, here, was 2:1 in favour of the former. Sandbh (talk) 01:29, 12 August 2017 (UTC)

Set the Ngrams to analyse more generic "rare-earth,rare earth" +s [2]. -DePiep (talk) 10:41, 13 August 2017 (UTC)

Take into account that "rare earth" might be a noun phrase (one of "rare earths") or improperly capitalized "rare Earth ...", which should not be hyphenated. (And "rare-earths" would be something strange.) Nevertheless, the usages looks comparable and, as I mentioned, probably depend on the publisher preferences. — Mikhail Ryazanov (talk) 04:31, 14 August 2017 (UTC)

So "rare-earth metals" as a term are not rare either. ;–) And the hyphenation or its absence is probably just reflecting the house style, which in our case recommends the hyphenated form. (BTW, my impression is that IUPAC is not even internally consistent regarding hyphenation and other notation, so the exact way they write something is probably not too important.) — Mikhail Ryazanov (talk) 01:54, 12 August 2017 (UTC)

To be sure, for any other IUPAC defined name such a change must be discussed beforehand, likely here. IOW it's controversial. It is not established that the earlier form is "wrong". -DePiep (talk) 08:54, 12 August 2017 (UTC)

• The IUPAC Red book p. 63/pdf, paragraph IR-3.5, recommends: "rare earth metal", "alkaline earth metal", not hyphened. I suggest we stick to this recommendation (as we do for aluminium, caesium, sulfur. BTW, there is no mention of "post-transition metals" so that can stay hyphened. Also, "f-block" is hyphened). The point is that it is a given name, not a description. Once we'd check the description for correctness, one can also end up proposing "actually not-so-rare-earth elements". I propose to remove the hyphen. -DePiep (talk) 11:20, 13 August 2017 (UTC)
  • Strictly speaking, IUPAC only mentions "rare earth metals", so "rare earths" or "rare-earth elements" (regardless of hyphenation) are not "IUPAC-approved" in that sense. However, the WP article is called "... elements" rather than "... metals", and it seems that "elements" are used more than "metals". Does it meant that we need to go and change all these "elements" to the IUPAC-approved "metals". Probably, not. And again, I do not believe that the lack of hyphen in that IUPAC publication is significant. — Mikhail Ryazanov (talk) 04:31, 14 August 2017 (UTC)

Off topic. Issue is whether "rare earth" is defined in adjective or in name form. -DePiep (talk) 18:14, 14 August 2017 (UTC)

"Rare earth" is not defined at all. The only occurrence is "rare earth metals", without any explanations.

Do you have any ideas how to contact IUPAC for clarification? I could not find any reasonable contact information in the book or on the website (writing to the secretariat is probably hopeless). I have a friend who apparently works in the same building as Fabienne Meyers (the IUPAC Associate Director) and can try to ask through her, but a more direct and official way would be better. — Mikhail Ryazanov (talk) 03:04, 15 August 2017 (UTC)

sigh. The topic is: the spelling of r.e. With or without hyphen? Is it a name or regelar words (ie grammatically adjective)? We know what iupac approves. Contact=red book. -DePiep (talk) 15:15, 15 August 2017 (UTC)

What do you mean by "name"? Proper names must be capitalized. Other terms are, grammatically, regular words. — Mikhail Ryazanov (talk) 23:23, 15 August 2017 (UTC)

"Name" as in: frozen, irrespective of their descriptive history. Word(s) with a meaning by themselves. And btw, names of chemical elements are proper and not capitalised. -DePiep (talk) 13:51, 25 August 2017 (UTC)

Can you recommend a book or article when I can read about these ideas? From what I know, names of chemical elements are not proper; neither are names of subatomic particles, chemical compounds, allotropes, minerals and so on. — Mikhail Ryazanov (talk) 03:14, 27 August 2017 (UTC)

(noarchive) -DePiep (talk) 20:32, 23 September 2017 (UTC)

Predicted metallicity colors

What would be the consequences of eliminating the predicted metallicity colors and simply using the unknown gray. It would significantly simplify the selection of a color palate. Where are they predicted colors used? Does someone know offhand, or perhaps someone knows how to search? They aren't used in any of the graphics in the main periodic table article. YBG (talk) 18:11, 26 August 2017 (UTC)

When redesigning the category colors, this is irrelevant (or must be made irrelevant). A category set requires 10+unk legend colors, an almost impossible task. Then add that they must comply with w3c contrast rules, and colorblindness guidances, it is clear that the degrees of freedom are contradicting (not a satisfying solution possible). Then to add the 'predicted colors' request is pushing it off the cliff. So in WP:PTCC, the predicted categories are second or third rate requirements. (For example, should/could be solved graphically otherwise). -DePiep (talk) 00:45, 27 August 2017 (UTC)

My hope is that the answer to my questions will reveal that predicted colors are unnecessary. I know that still leaves a hugely overconstrained set of requirements, but IMO every bit helps. YBG (talk) 03:53, 27 August 2017 (UTC)

Actually I rather agree with YBG. The predicted chemistry of the elements past 120 is so complicated that declining to assign a category may be the best bet; the familiar chemistry you learn from hydrogen to oganesson will no longer help you, although this may disappoint some "periodic table fans". I would perhaps suggest solid grey for "unknown chemical properties" and solid white (or transparent) for "we haven't discovered the element". Double sharp (talk) 04:07, 27 August 2017 (UTC)

Agree. Sandbh (talk) 04:45, 27 August 2017 (UTC)

So there is a sound scientific reasoning to abandon mentioning "predicted" this way (coming from long-time involved editors). That could conclude "Remove named category colors for predicted" (without changing the textual mentioning in the infoboxes etc I assume?). With this, the coloring issue is moot (gone).

Next: add a color for "undiscovered" as opposed to "unk chemical properties".

Prior question(!): is "unknown chemical properties" correct wording, or should "physical" be included? E.g., saying "Unknown properties" better?

Then, a new color ("Undiscovered") being white is a bit difficult for unbordered cells (such as the micro PT in the infobox). We could use the "unknown properties" grey just as well (for now). Will look for a new color. -DePiep (talk) 11:05, 27 August 2017 (UTC)

I think Double sharp's comment to use "solid white (or transparent) for 'we haven't discovered the element'" is a way of saying that if there is not yet a claim for discovery, there would be no cell shown on the periodic table. Until someone claims discovery of Z > 120, we probably don't need to worry about this. YBG (talk) 18:00, 1 September 2017 (UTC)

Well, for the extended periodic tables, I would suggest that the atomic number alone be included, with a border but no cell colour. Double sharp (talk) 05:00, 2 September 2017 (UTC)

Proposal

It seems that our lighter predicted metallicity shades are only used for predicted elements in an extended periodic table. I suggest that we modify our border options as follows:

• Border styles (currently): Primordial
• From decay
• Synthetic

• Border styles (proposed): Primordial
• From decay
• Synthesized
• Theorized

This eliminate the need for a special shade to indicate predicted metallicity. For predicted elements, we would have the option of showing the "Theorized" border style with either a specific metallicity color or with the "Unknown properties" color. Thoughts? YBG (talk) 23:29, 12 September 2017 (UTC)

The trouble is that for some elements late in the 7th row (Mt, Ds, Rg, Nh, Fl, Mc, Lv, Ts, Og), the element is known (not predicted), but the chemistry is unknown (predicted). The rest of your idea of course makes me remember the old days before 2010 when Ts (well, "Uus" then) was marked without an outline for the cell as "Undiscovered". ^_-☆ Double sharp (talk) 23:42, 12 September 2017 (UTC)

For those elements, we could use the "Synthesized" boundary along with either a specific metallicity color or an "unknown chemical properties". But your point is well taken. We would not be able to distinguish between synthetic elements with a known metallicity and those with a predicted metallicity. Sigh. YBG (talk) 23:51, 12 September 2017 (UTC)

Yes we could add "Theorized" to the border set (YBG proposal). That is in the right legend series, when meaning "The element is theorized". Today, will only show in extended PT. (Note: when a new element, 119 and up, is discovered but not confirmed, we'd need another one more border type probably). All fine.

Then, for the predicted metallicity (chemical properties), could do:

1. bg white for Theorized elements [new]. Meaning: "Theorized or unk category only", no specific category mentioned. Element theorized, so its properties must be too. Covers all 'predicted', 'extrapolated', etc. claims. Article text may be more specific.
2. bg grey for 'unk chem properties' [as is]. Used for those ₁₀₀Mt and heavier ones (not Cn).
3. remove from tables: all "(predicted)" categories and their shades. So, not just remove the colour, but also remove that categorisation (no category "alkali metal (predicted)" will exist any more in the PTs). Prediction claims still can be used textually in the article and in the infobox.

To check: also dropping category "superactinides". Can the extended PT do without this? (textually can stay, we also can mark them in a micro PT). We keep the the predicted block color ('g-block, theorized'), by Aufbau and Pyykkö.

To check: see Extended_periodic_table#History: Mt-Og not Cn will turn grey then.

Note 1: Regular PT will not change (same colors, same categories, same meaning).

Note 2: Need to check effects of white bg color when no borders (compact PT, micro PT); must be solved; shall not block this development. -DePiep (talk) 09:15, 14 September 2017 (UTC)

Is "Theorized" an English word and if so, what is its grammatical position? Is there a more simple wording possible, to invite more average readers? -DePiep (talk) 22:10, 14 September 2017 (UTC)

Theorized. Headbomb {t · c · p · b} 23:22, 14 September 2017 (UTC)

As for using a different word, 'predicted' might do well. Headbomb {t · c · p · b} 11:46, 15 September 2017 (UTC)

Headbomb Great, "predicted" is better (to me at least). (Of course I could have google 'theorized' myself, but one you got the point—and made some thing better from it). -DePiep (talk) 19:57, 15 September 2017 (UTC)

Thanks for all your input, but I think I should withdraw my proposal, at least as it currently stands due to additional complications: (1) The metallicity colors may also needed for elements that have already been discovered, but whose properties are unknown. (2) There are other states besides primordial / from decay / synthesized / predicted, including (a) claimed but not affirmed and (b) attempted but not yet attained. We don't need to represent all possible intermediate states, but it does give cause for pause. YBG (talk) 14:46, 15 September 2017 (UTC)

Please No! Let's flesh this out. There are two separate topics: "element status" [border] and "chem properties" [metallicity category color]. Then per element, apply both classes [and so style], once. (Do not mix up border-element with bgcolor=metallicitycategoty. Ever).

Discuss remaining issues. -DePiep (talk) 19:49, 15 September 2017 (UTC)

Implementation

"Theorized" → "predicted" - 20:00, 15 September 2017 (UTC)

Here are some mockups for what it would be like. Please keep the content discussion at #Proposal (this section is just trying its outcome: effects & colors).

• New legend (See also Testcases)

Primordial

From decay

Synthetic

Claimed

Predicted

Border shows natural occurrence of the element [demo-2018]

Template:Periodic table legend/Category-unk2017

• Note on new border (double line): Only 2D-line available, next to: solid, dotted, dashed. 'none' is not usable. See testcases. -DePiep (talk) 10:31, 14 September 2017 (UTC)

-DePiep (talk) 10:31, 14 September 2017 (UTC)

• Todo:

1. Non-bordered PTs do not show category Theorized (white) well. {{Infobox element}}, PT micro, compacte PT (navbox)
2. Sandbox affected PTs (mostly extended ones).
3. Add |engvar=en-UK to write TheoriSed.
4. Check in mobile view

-DePiep (talk) 10:31, 14 September 2017 (UTC)

Implementing the recoloring of group 12

Now that the RfC has been closed and the change accepted at § Proposal: Colour group 12 as post-transition metals, how do we go about implementing it? Is this something that can be done piecemeal over time or would it be better to perfect a complete list of the necessary changes and then make them more-or-less all-at-once? YBG (talk) 17:33, 1 September 2017 (UTC)

I'd say go ahead. Please mention in the editsummary: "RfC on group 12", e.g.

[[:en:Wikipedia_talk:WikiProject_Elements#Proposal:_Colour_group_12_as_post-transition_metals|RfC on Group 12]]

When text changes, best to check the whole article (or section, subtopic) for the change.

Templates: list of Periodic table templates (and images). For Images, please add in Commons: [[Category:Periodic table by enwiki-2013 categories]] for future ease (when actually used in our articles).

-DePiep (talk) 07:13, 2 September 2017 (UTC)

Done (most of) the template tables. That's the easy part, texts to do. Please add something like "RfC on group 12 colors" to the editsummary, to prevent double checking. -DePiep (talk) 09:30, 8 September 2017 (UTC)

I didn't see your post earlier, so I edited some texts without including the edit summary: I'll include it from now on. Double sharp (talk) 10:12, 8 September 2017 (UTC)

IUPAC

I just had a careful read of the IUPAC Red Book 2005, and was surprised to see that "transition metals" is not an IUPAC-approved collective name.

All that the Red Book says is:

Optionally, the letters s, p, d and f may be used to distinguish different blocks of elements. For example, the elements of groups 3–12 are the d-block elements. These elements are also commonly referred to as the transition elements, though the elements of group 12 are not always included…

The Gold Book on the other hand says that a transition element is, "An element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell." The Gold Book cites The Red Book 1990 as its source, which is two editions out of date; later Red Books were published in 2000, and 2005. The Gold Book entry is therefore (apparently) without foundation.

According to the Red Book, the only IUPAC-approved collective names are: alkali metals, alkaline earth metals, pnictogens, chalcogens, halogens, noble gases, lanthanoids, and actinoids. Sandbh (talk) 06:15, 3 September 2017 (UTC)

Side track: should we (at WP) rediscuss "lanthanoids" vs "lanthanides" (Ln) then? -DePiep (talk) 07:37, 3 September 2017 (UTC)

So IUPAC does not say "transition metals", but they do say "transition elements" right? What would be the issue then? All transition elements are metals, no problem. (Same with "rare earth elements" and "rare earth metals", see above). -DePiep (talk) 07:45, 3 September 2017 (UTC)

The trouble is that in some cases (Mt, Ds, and Rg), we have not actually done the chemical experiments needed to establish them as metals (or anything else really). So while they are transition elements by definition, whether they are transition metals is yet unknown (though no one seriously doubts it). Double sharp (talk) 05:06, 5 September 2017 (UTC)

What about changing our category name to "transition elements"? Granted, that only hides the issue, since they would still be in our supercategory of metals. But it would be nice to use the exact term used by the IUPAC. YBG (talk) 05:53, 5 September 2017 (UTC)

1. Double sharp just said that they are not confirmed to be metals. So they should not be in supercategory "metals" then? 2. How are they transition "by definition"? Isn't that by properties? We just did establish group 12 being transitions this way. -DePiep (talk) 06:33, 5 September 2017 (UTC)

3. Does IUPAC define "metals" at all anywhere? -DePiep (talk) 06:34, 5 September 2017 (UTC)

Regarding (1), they are indeed not under the "metals" supercategory in our table, but rather in the "unknown chemical properties" one. On (2), the definition given by IUPAC is simply "groups 3-11 or groups 3-12"; so Mt, Ds, and Rg are assigned to groups 9, 10, and 11 respectively and so must literally be considered transition elements by this definition. (Of course, the reason for the definition lies in the properties the elements in these groups share, but that's not what is explicitly stated.) On (3), the IUPAC Gold Book appears to lack an entry on "Metal". This state of affairs is not particularly surprising, although it is surely disappointing. We can take some comfort in that this is not at all localised to chemistry: for quite some time now Grove's Dictionary of Music has similarly lacked an entry on "Music". Double sharp (talk) 06:58, 5 September 2017 (UTC)

As I get it, the main issue is not IUPAC red book definition, but our categorisation as "metal" (as in "transition metal") when not proven to be a metal. Meanwhile, all are proven to be transitional (i.e., the correct part of categorisation names). -DePiep (talk) 09:32, 8 September 2017 (UTC)

Yes, that's absolutely right. Double sharp (talk) 10:11, 8 September 2017 (UTC)

Sorry, it seems that my suggestion has created a bit of a tempest in a teapot. Using "transition metal" provides consistency between our category names, but using "transition element" provides consistency with IUPAC. Not sure which consistency is a foolish hobgoblin and which isn't. So IMO it really is a bit of "two 15s make one 30" or "six of one, half a dozen of the other" -- at least until such time as someone demonstrates the existence of a transition nonmetal. And if that were to occur, we've got even bigger categorization fish to fry. YBG (talk) 16:51, 8 September 2017 (UTC)

We almost had it with predictions of semiconducting Cn; now that is marked as a PTM, which only delays the problem. But there are so many predictions that I am basically prepared for just about anything for that element. Double sharp (talk) 23:45, 12 September 2017 (UTC)

TFA reruns

Recently it was decided that because of insufficient new FAs, older FAs could be rerun at Today's featured article after five years have elapsed. A provisional list is in preparation of important articles that could be rerun, and Oxygen is today's TFA. There are other elements on the list, Helium, Hydrogen and Uranium, but they have problems such as dead links or uncited text. Is there any chance of these being licked into shape to give them a chance of running again? Jimfbleak - talk to me? 05:50, 5 September 2017 (UTC)

Well, we have enough old FAs that I suspect that we could, as soon as we actually decided on which one we were going to run! ^_^ H and He seem to be excellent ideas to me; I will try to look through and cite anything I can find the source for quickly on a first pass. Double sharp (talk) 06:49, 5 September 2017 (UTC)

The Wikipedia:WikiProject Elements/TrophyBox has 29 FA articles now. Cannot reach WP:PETSCAN now, but I'd like to cross-check that list with Category:Featured articles that have appeared on the main page (7,240). Jimfbleak -DePiep (talk) 08:17, 6 September 2017 (UTC)

• See Category:FA-Class chemical elements articles (29) (not: 1 FL, 1 FT).

PetScan says: all articles have been TFA (unless my petscan is wrong...). -DePiep (talk) 09:52, 8 September 2017 (UTC)

DePiep, My comment above was about reruns of TFAs that are more than five years old. I reran Oxygen this month, but the others that are old enough have deteriorated below what is acceptable for a TFA (multiple dead links or uncited text), which is why I wanted to see if the project was interested in mending them Jimfbleak - talk to me? 10:45, 12 September 2017 (UTC)

I see. For now it's just helium, hydrogen and uranium to re-upgrade into FA for this. See also Talk:Periodic table#TFA rerun. (I'm afraid I cannot solve that btw). -DePiep (talk) 12:59, 14 September 2017 (UTC)

RfC: Replace categories of poly/diatomic nonmetal with less active/active nonmetal

I am seeking comments on a proposal to change part of the current nonmetal categorisation scheme, as follows: -- Sandbh (talk) 03:35, 9 September 2017 (UTC)

From	Polyatomic nonmetal C, P, S, Se	Diatomic nonmetal H, N, O, F, Cl, Br, I
To	Less active nonmetal H, C, N, P, S, Se	Active nonmetal O, F, Cl, Br, I

Origin
The origin of this proposal can be traced to literature conceptions of nonmetals as either halogens (F, Cl, Br, I, At), noble gases, or other metals (H, C, N, O, P, S, Se), with the last of these three groupings representing a poorly characterised "orphan" or leftovers category.

The Wikipedia periodic table used to show the three categories of halogens, noble gases, and other nonmetals up until mid-2013 when we recategorised astatine as a metalloid. Astatine has been predicted to have a metallic crystalline structure, which suggests there may be grounds to categorise it as a post-transition metal. But condensed astatine has not yet been observed so for the moment is left as a metalloid.

When astatine was recategorised as metalloid the opportunity was taken to get rid of the nondescript "other nonmetal" category name by moving C, P, S, and Se into a new polyatomic nonmetal category, and moving H, N, and O, into a new diatomic nonmetal category, along with F, Cl, Br, and I. We got rid of the term other nonmetal since it wasn't based on any consideration of the shared attributes that should characterise a useful category name. And it's an awkward term to use if you want to say something like, for example, "nonmetals form compounds with metals and other nonmetals" or "like hydrogen, carbon forms molecular covalent compounds with most other nonmetals."

You can see the use of the current polyatomic and diatomic arrangement, which is based on structural considerations, in the nonmetal article. It works, but I've never been completely satisfied with it since it does not necessarily show the most relevant trends associated with nonmetallic character. Chemists tend to think of nonmetals primarily in terms of such things as oxidative power, electronegativity, activity, reactivity, anionic behaviour, or electron affinity, rather than whether the nonmetals have polyatomic or diatomic molecular structures.

Proposal
In retrospect I think it would better to categorise H, C, N, P, S, and Se as less active nonmetals, and O, F, Cl, Br, and I as active nonmetals. Such a division would be based on multiple electrochemical properties, rather than a single structural consideration.

In this arrangement, O, F, Cl, Br, and I are individually and collectively characterised by relatively high ionisation energies, high electronegativities, high electron affinities, high oxidising power, and simple anion formation, consistent with their depiction in the literature.

H, C, N, P, S and Se are unable to consistently match the active nonmetals across the aforementioned electrochemical properties.

The proposed category names, which end with the form "-ive", can accommodate the fact that, for example, while the overall tendency of H and S is to act as reducing agents, they are sometimes capable of acting as oxidants. Another example would be the fact that nitrogen has a higher electronegativity than bromine and iodine. Now nitrogen does show some "active" character in its capacity to form hydrogen bonds and complexes, but it is a poor oxidising agent unless combined with an active nonmetal like O or F; and it is a reluctant anion former, unlike the active nonmetals. So, at the broadbush level being dealt with here, N is a less active nonmetal, with some "active" nuances if you dig deeper. This is consistent with the meaning of the "-ive" suffix: "that performs or tends toward or serves to accomplish an indicated action esp. regularly or lastingly" or "having a tendency to, having the nature, character, or quality of, given to (some action)". Hence it has the meaning of a tendency rather than a finality.

On the question of boundary overlaps such as these I turn also to Jones (2010, pp. 169–171):

"Though classification is an essential feature of all branches of science, there are always hard cases at the boundaries. The boundary of a class is rarely sharp…Scientists should not lose sleep over the hard cases. As long as a classification system is beneficial to economy of description, to structuring knowledge and to our understanding, and hard cases constitute a small minority, then keep it. If the system becomes less than useful, then scrap it and replace it with a system based on different shared characteristics."

Similar overlaps occur elsewhere in the periodic table. For example, beryllium in group 2, an alkaline earth metal, behaves chemically more like aluminium in group 3, a post-transition metal; the group 3 transition metals scandium, yttrium, lanthanum and actinium behave largely like the alkaline earth metals or, more generally, s block metals; and gallium in group 13, tin in group 14, and bismuth in group 15, all of which are post-transition metals, have some metalloid properties.

The periodic table nevertheless retains its status as an organising icon of chemistry.

Formative discussions
The proposal is a culmination of around six months of discussion with members of WikiProject Elements. We concluded that these two categories subdivided the eleven non-noble nonmetals in a manner that would be more consistent with differences in nonmetallic character. The only other recategorization that received a significant amount of discussion was placing all eleven nonmetals in a single category but this categorization obscured significant differences within the eleven. Having agreed on the categorization, much of our discussion revolved around determining the best category names. We considered but discarded a range of alternative paired category names, including: weak/strong; intermediate/corrosive; reactive/corrosive; reductive/oxidative; covalent/ionic; heterogenic/corrosive; foundation/corrosive; formative/corrosive; and less active/corrosive.

What does IUPAC say?
IUPAC does not provide any guidance on category names for the nonmetals. They have endorsed use of the terms "noble gases" and "halogens" however these are group names rather than category names such as post-transition metal, and metalloid, neither of which are IUPAC endorsed. We do show the group names in our larger periodic table, but we don't have a halogen colour category since we count astatine as a metalloid, which has a different colour category.

What does the literature say?
As it turns out, there is support in the literature for the terms "less active nonmetal", and "active nonmetal". Here are some quotes that use this terminology and highlight the distinctiveness of O, F, Cl, Br, and I.

• "A salt is a compound of metal ions and nonmetal ions. The halogens being active nonmetals are excellent salt-formers." (Allen et al. 1942, p. 484)
• "What, in general, is the difference between active metals, less active metals, less active non-metals, active non-metals, and inert gases…?" (Friedenberg 1946, p. 230)
• "The halogens and oxygen are the most active non-metals." (Lee & Van Orden 1965, p. 197)
• "The most active non-metals are in the upper right-hand corner of the chart; the most active metals are in the lower left-hand corner." (Luder 1965, p. 39)
• "From Group V on, the series passes from the less active nonmetals to the most active ones, like chlorine, in Group Vll." (Gardiner & Flemister 1967, p. 22)
• "Across each period is a more or less steady transition from an active metal through less active metals and weakly active non-metals to highly active nonmetals and finally to an inert gas." (Beiser 1968, p. 234)
• "If you don't count the noble gases, Family 18, the most active non-metals are found in the upper right corner." (Aldridge 1993, p. 175)
• "Active nonmetals, such as the halogens (Group VIIA) and oxygen, are good oxidizing agents." (Grolier Incorporated 1999, p. 162)
• "Oxygen is one of the most active nonmetals and one of the most important. It forms compounds with all the elements except the light noble gases (He, Ne, and Ar). In general, oxygen forms ionic compounds with metals…" (Hill and Petrucci 1999, p. 903)

What the new scheme would look like
A draft rewrite of the nonmetal article using the proposed descriptive category names of less active nonmetal and active nonmetal can be found here.

The proposed scheme would result in a more balanced distribution of nonmetals, from 4 + 7, to 6 + 5.

Summary
I propose to replace the diatomic and polyatomic nonmetal categories with the newly constituted categories of less active nonmetal, and active nonmetal, as sourced from the literature. These categories are more consistent with the most relevant trends associated with nonmetallic character.

References

• Aldridge B et al. 1993, Science interactions, Glencoe/McGraw-Hill, New York
• Allen JS, French SJ, Woodruff JG 1942, Atoms, rocks and galaxies: a survey in physical science, Harper and Brothers, New York
  
• Beiser A 1968, Perspectives of modern physics, McGraw-Hill, New York
• Friedenberg EZ 1946, A Technique for developing courses in physical science adapted to the needs of students at the junior college level, University of Chicago, Chicago
• Gardiner MS & Flemister SC 1967, The principles of general biology, Macmillan, New York
• Grollier Incorporated 1999, The encyclopaedia Americana, vol. 21, Danbury, Connecticut
• Hill JW & Petrucci RH 1999, General chemistry: An integrated approach, Prentice Hall, Upper Saddle River, New Jersey
• Jones BW 2010, Pluto: Sentinel of the outer Solar System, Cambridge University Press, Cambridge
• Lee GL & Van Orden HO 1965, General chemistry: Inorganic and organic, 2nd ed., Saunders, Philadelphia
• Luder WF 1965, General chemistry, Saunders, Philadelphia

— Sandbh (talk) 23:30, 9 September 2017 (UTC)

Survey

Indicate Support or Oppose below.

1. oppose on the basis of defining hard categories may be counterproductive as you said there are no hard divides. Also oppose on the basis IUPAC gives no guidance on this suggesting classification like this is not useful. EvilxFish (talk) 11:17, 10 September 2017 (UTC)
   • Though I would note that the current polyatomic/diatomic divide is not given by IUPAC either; following their (lack of) classification in the region would lead to not splitting the nonmetals at all. Which is not a bad choice either. ^_^ Double sharp (talk) 11:57, 10 September 2017 (UTC)
   • However the polyatomic/diatomic divide is something one may find in mainstream textbooks/reviews. This is not the case for this proposal, though things may be described as "more active" than something else they are not categorized in accordance with the proposal. EvilxFish (talk) 11:10, 12 September 2017 (UTC)
2. If IUPAC fails, ignore them We considered not splitting the non-noble nonmetals at an earlier stage; they would then be called chemically active nonmetals. However, the literature presented above makes clear that the distinction we propose is useful in understanding the chemistry of the nonmetals. I myself support. Parcly Taxel 12:53, 10 September 2017 (UTC)
3. Support. I am particularly pleased and convinced by the main rewritten nonmetal article (sandbox). -DePiep (talk) 15:30, 10 September 2017 (UTC)

   The only reason for rejection I find acceptable is WP:FRINGE: "opinions [sic] with representation in proportion to their prominence". I think this is what multiple editors here referred to. Maybe WP:UNDUE is in play too. Per my quoting & analysis of the IUPAC Recommendations, the criteria "not IUPAC accepted" is used wrongly (IUPAC does not say anything about, er, unmentioned categories. For example, categories metal, metalloid, nonmetal (huge in RL and science), "are not Recommended by IUPAC", that should to read: IUPAC does not say anything about them). "Useful and acceptable" information: not the encyclopedic criteria to include/exclude. And Wikipedia has the due right to add element classification. For that's what the periodic table is about. -DePiep (talk) 09:52, 7 October 2017 (UTC)

   • Support, after some long consideration over the months. Of all the possible divisions, this seems to reflect what is going on the best and accord with as many properties of the elements in question as it seems possible. Double sharp (talk) 15:34, 10 September 2017 (UTC) (struck out to think a bit longer and formulate a longer reply ^_^) Double sharp (talk) 02:29, 11 September 2017 (UTC)
4. Oppose. Sorry I haven't been active lately (and I won't be for quite a while), but I feel I have to comment on this one. I haven't been watching the discussion, so please write if I am missing something. But also have in mind that if I don't see it from my first look, chances are, many others won't, either.

   First of all, by no means am I a fan of the current poly-/diatomic divide. I think allotropy is a very poor reason for a general classification.

   That being said, I think "active nonmetals" is a poor term. Precisely, it is poor because the word "active", by its very nature, is a relative quality. "Polyatomic" and "diatomic", as inappropriate for a general classification as they are, are unambigous (or close to that, but hardly will anyone not understand that the standard conditions are meant, and unusual cases like high pressure were not considered): it's either two atoms in one molecule of the free substance or more (or a non-molecular sturcture). That's a clear divide. Both terms are clear by themselves. What's an "active" nonmetal, though? How active does it have to be to count as "active"? Can you define this term without looking at other elements? Even worse, what's a "less active" one? I easily see the noble gases being counted as those "less active" nonmetals.

   Imagine the infobox for P, for example. It says, "less active nonmetal." This phrase is asking for a "less active than what?" So the term is not just unclear, but also incomplete.

   While I am eager to be proven wrong, I continue to think that there is no good divide at all. I see myself agreeing on a divide with two clear self-descriptive relevant terms, but throughout all of this time, we haven't found a single one. This particular divide does not highlight anything, even anything as irrelevant as allotropy; it is a divide for the sake of having a divide.--R8R (talk) 17:36, 10 September 2017 (UTC)

   See re #R8R below. -DePiep (talk) 18:28, 10 September 2017 (UTC)

5. Oppose While some nonmetals may sometimes be described being more active than others, it is not useful to divide the nonmetals into "more active" and "less active" ones for a couple reasons.

   1. How "active" an element is is can be defined in numerous different ways, so it's a rather vague attribute.

   2. Even with a clear definition of how "active" an element is, there's still no clear divide seperating the more active elements from the less active ones, so classifing dividing them that way is rather subjective. For example I wouldn't consider iodine to be a particularly active element or sulfur to be a particularly inactive element. OrganoMetallurgy (talk) 19:57, 10 September 2017 (UTC)

   See re #OrganoMetallurgy below. -DePiep (talk) 06:08, 11 September 2017 (UTC)

6. Support, as proposer. The various ways of describing the activity of the nonmetals in the literature turn out to be quite similar to one another. They are not identical but there is enough common ground to support the structuring of our knowledge and understanding of the chemically active nonmetals into two classes. Yes, there are small overlaps at the boundaries just as there are overlaps between some of our other categories. But these are not worth losing any sleep over, as long as they are in the minority, and the classification system is beneficial to economy of description and our understanding of the progression going across the periodic table, as described in the literature, i.e. active metal → less active metal → less active nonmetal → active nonmetal (with the noble metals and noble gases as adjuncts).

   The most non-metallically active of the nonmetals are O, F, Cl, Br, and I. For example:

   • "The halogens and oxygen are the most active non-metals." (Lee & Van Orden 1965, p. 197).
   • "…under SSIMS [secondary ion mass spectrometry] conditions…the electronegative elements, i.e. oxygen, fluorine, chlorine, bromine and iodine, give intense negative ion signals." (Briggs 1998, p. 119).
   • "Of the nonmetals, oxygen and the halogens are highly reactive." (Frank, Miller & Little 2004, p. 19)
   • In discussing the redox behaviour of the elements, Silberberg (2006, p. 548), in a periodic table extract, shows only O, F, Cl, Br, and I as strong oxidising agents.
   • "A few nonmetallic elements, such as oxygen and the halogens (F₂, Cl₂, Br₂, and I₂) are strong oxidizing agents…" (Moore & Stanitski 2015, p. 114)

   They are individually and collectively characterised by high ionisation energy, high electronegativity, high electron affinity, high oxidising power, and simple anion formation. The "less active nonmetal" and "active nonmetal" descriptive terms are drawn from the literature, as indicated. Iodine, as a corrosive halogen, is routinely counted as being among the most active of the nonmetals. That being said, I think it is sufficient to describe iodine as an "active nonmetal" rather than a "particularly active nonmetal" and sulfur as a "less active" nonmetal, rather than a "particularly inactive" one.

   I do not think the expression "active", as in "active nonmetal", is less relative than the term "noble", as in "noble gas". I think concerns such as these, about the relative nature of adjectives, are also not worth losing any sleep over, in the broader context of what we are trying to do. This is to reflect, as best we can—even if we fall short of perfection—the broad contours of the relationships among the elements, having regard to the literature.

   A small observation about IUPAC. The only IUPAC-approved collective names for sets of elements are alkali metals, alkaline earth metals, pnictogens, chalcogens, halogens, noble gases, lanthanoids, rare earth metals, and actinoids. We do not use lanthanoids, and actinides, we use "lanthanides" and "actinides". Note that "transition metal" is not IUPAC-approved. IUPAC only says that the elements of groups 3–12 are the d-block elements and the same elements are commonly referred to as "transition elements". We instead used the category name "transition metal" and we also use the category names "post-transition metal" and "metalloid". That IUPAC gives no guidance on the use of these terms does not suggest these classifications are not useful.

   In conclusion, the proposed division is literature-based and the proposed category names are draw from the literature.

   I regret the length of this support however there were many issues raised that I wanted to address or provide further supporting information on.

   References

   • Briggs D 1998, Surface analysis of polymers by XPS and static SIMS, Cambridge University Press, Cambridge
     
   • Frank DV, Miller S & Little JG 2004, Chemical Interactions, 3rd ed., Prentice Hall, Upper Saddle River, New Jersey
     
   • Lee GL & Van Orden HO 1965, General chemistry: Inorganic and organic, 2nd ed., Saunders, Philadelphia
     
   • Moore JW & Stanitski CL 2015, Chemistry: The molecular science, 5th ed., Cengage Learning, Australia
     
   • Silberberg MS 2006, Chemistry: The molecular nature of matter and change, 4th ed., McGraw-Hill, Boston

   Sandbh (talk) 01:44, 11 September 2017 (UTC)

   • Note there is a subtle difference between saying an element is the "most active", and categorizing an element as either "active" or "non-active". Perhaps I did place too much importance on IUPAC however terms like transition metal may be found in all mainstream chemistry textbooks however the classification as described above cannot. Much love EvilxFish (talk) 11:16, 12 September 2017 (UTC)
7. Oppose. I thought about saying weak oppose (b/c I think that with coloring schemes for elements is not super important) but my feelings are stronger than that because I dont like the terms "active and inactive", which sound alchemical or medieval to me. Also they are terms chemists just dont use. The supporting references do not convince me because literally thousands of books have sections on this theme, and some will support diverse ideas. It seens misguided to suggest to general readers that we do. We know that F2 will eat one alive, but "inactive" P4 is not exactly friendly in air. Having stated some of my views, the proposal seems to be well done, and no crisis will befall Wikipedia should it pass. --Smokefoot (talk) 14:17, 11 September 2017 (UTC)
8. Support. The categories are significantly more helpful than the current diatomic/polyatomic, and relatively well defined. Most (if not all) examples of high reactivity of the "less active" nonmetals (e.g., P & N) occur with the help of oxygen or one of the halogens, so that activity can be ascribed to those elements. The category names are not as catchy as I'd like, but they are infinitely better than the previous scheme which included "other nonmetals". YBG (talk) 09:02, 13 September 2017 (UTC)
9. Oppose The changes seem less scientific and borderline WP:OR to me. Firstly we're moving from a quantitative to a qualitative description: under standard conditions C, P, S, Se are undeniably polyatomic and H, N, O, F, Cl, Br, I are undeniably diatomic, as soon as we start talking about reactive or unreactive the questions being 'reactive relative to what? What about under X and Y conditions etc' its messy. The literature you cite doesn't win me over either, you seem to have found excerpts of authors discussing the reactivity of non-metals, rather than anyone formally offering up a categorisation scheme based on 'active vs less active'.--Project Osprey (talk) 17:58, 18 September 2017 (UTC)
10. Reluctant oppose (changed from Support above). I really like the idea of this categorisation scheme, and totally agree that, say, N and P are certainly not in the same league of reactivity as F and Cl. But while such thinking is assuredly useful in a qualitative sort of way, it remains that the reactivity of nonmetals can be sliced up in many different ways, and while sources indeed show that some nonmetals are more reactive than others they do not separate the more from the less reactive ones in such a thorough way. The current classification is a least quantitative, undeniable, and still correlates with the broader trend. One can quibble about H and N, but the nonmetals as a bunch are so singular that I would expect such things to happen anyway. What pushes me over most of all to this side is the reasoned opposes of various active editors on Wikipedia, who are active in chemistry. If the proposed classification is not going to be as well-received by chemists as the current one, then I think it would be better to leave well enough alone. Double sharp (talk) 05:49, 20 September 2017 (UTC)
11. Oppose Reactivity is subjective to a degree, the quantitative poly vs diatomic seems much more clear cut. Tornado chaser (talk) 18:09, 23 September 2017 (UTC)
12. Oppose Agree with those who dislike the arbitrary nature of the attributes of the elements in question. Also dislike the non-fundamental nature of some of the bases for classification of elements, when the attributes are chemically variable, but what is being classified is an element, fundamentally a physical concept. Compare for example classification of elements by their allotropic nature, with classification by their atomic numbers. The latter is a categorical constant, the former is contingent on circumstances. Even H may be regarded as a metal under sufficient pressure at appropriate temperatures, and several other elements change their metallic status according to their ambient conditions or mode of preparation. Conversely, in stellar classifiction, "metal" means something totally different, in effect, atomic number >2, with no reference to chemistry at all.
    Now, I do realise that fuzzy classifications such as those proposed here are of practical importance in chemical communication and concepts, and I do NOT insist that no terminology of the type can be acceptable, and I furthermore accept that arbitrary classifications of groups such as noble gases, alkali metals, and perhaps halogens are useful and acceptable, but that leaves a lot of far messier groups and I do reject the idea of using them as definitive bases for partitioning the entire periodic table. Whoever said that there is ANY single scheme suitable for the entire periodic table under all circumstances? Perfectly logical schemes could partion very heavy elements from lighter elements in the same groups; consider separating say, Astartine from the halogens. There is no logical need or basis to do so, And even if we were to come up with a consistent and comprehensive scheme, that is NOT in our job description within WP. Until IUPAC elected to notice and accept what we came up with, it would be misleading to our readers to suggest that our classification were definitive. I say the topic is at present too messy for us to plump for any one option. JonRichfield (talk) 11:48, 26 September 2017 (UTC)

    See my "re JonRichfield" below. -DePiep (talk) 09:39, 7 October 2017 (UTC)

13. Oppose as a replacement because I don't read that the sources justify a complete replacement. CuriousMind01 (talk) 00:32, 9 October 2017 (UTC)
14. Support adding the proposal as an additional point of view, because per WP:Neutral Point of View all viewpoints are to be expressed per their weight. I think the sources presented support presenting the proposal as another valid point of view, and not as a fringe theory. The mission of Wikipedia editors is not to decide the correct or most liked or best point of view or omit dislikes, but to report all points or view/theories/facts per the weight presented in reliable sources. CuriousMind01 (talk) 00:32, 9 October 2017 (UTC)

Discussion

• Practical question: when does a survey thread be moved/continued into this Discussion section? (Example in case: first Survey by EvilxFish 11:17, 10 September 2017). -DePiep (talk) 14:50, 10 September 2017 (UTC)
• @EvilxFish: [3]

Your claim it being "counterproductive" is too strong. Sure a hard category is preferable (like with the noble gases), but absence of it does not invalidate categorisation. The "productive" point of categorisation is: it shows a trend in the periodic table. Yes for example nitrogen is doubtful in here (could be argued to be an active nonmetal), but that does not invalidate the trend. More in general, the periodic table is filled with such doubts in detail, or even contradictions. However, by looking at the grand tableau the trends show useful information about periodic grouping and behaviour. After all, it was Mendeleev who started ignoring local problems (atomic weight order did not match —then unknown— atomic number order, so he just boldly flipped tellurium and iodine to make them fitting, correctly in hindsight; don't try this at home on wiki), thereby solving the magnificent scheme quest. So, when hard borders are missing, we can endeavour in soft borders. It is no secret that IUPAC is not the forerunner in this, nor is expected to be that. This being Wikipedia, Sandbh has done a great job in exploring literature on this, and painting a great picture with this fine-haired broad brush. -DePiep (talk) 15:17, 10 September 2017 (UTC)

@DePiep: I would like to first begin by acknowledging that I work in computational chemistry so may not have the full knowledge of this particular issue as it lies outside my field of expertise. I would also like to say that as a computational chemist I live in a box and work on another thus am not the best at explaining things. That being said I stand by what I said about it being counterproductive. I do this on the assumption that this categorization is not something commonly found in mainstream chemistry textbooks, articles and is not acknowledged by IUPAC thus it would be best for wikipedia (being an encyclopedia) to follow suit. I acknowledge the effort of the proposer on preparing this, his dedication to improving the encyclopedia is commendable, that being said the effort put into the proposal is irrelevant when determining if it is a good idea to pursue. Kind regards EvilxFish (talk) 08:44, 11 September 2017 (UTC)

Thanks. I'm way less into chemistry. I think that "not stated by IUPAC" does not imply "not accepted". Acceptance is done in literature. Do I understand that you think it best to make the non-noble nonmetals (NNNMs) into one category? -DePiep (talk) 09:53, 11 September 2017 (UTC)

@DePiep: As mentioned before wikipedia is an encyclopedia and thus uses Wikipedia:Secondary sources, for good reason as well. Even if a few journal articles seem to suggest something is commonly used, that does not mean it is and a large amount of effort would need to be exhausted to determine a consensus on an issue (something for the sake of wikipedia is left to textbooks and review writers). As for the IUPAC thing, one should place importance on adhering to the accepted standard for chemical communication (even had a debate in the past about should it be 15 kelvin or 15 kelvins which was settled by going to the IUPAC standard). Whereas one could argue that there are things outside of IUPAC that are commonly used, this is not the case for this issue and the classification is not used in mainstream chemistry communication. As for your question, try googling "non-noble nonmetal" and you will see that this category is not used. Much love EvilxFish (talk) 10:28, 12 September 2017 (UTC)

wrt "non-noble nonmetals": doesn't matter what google says. It is a description of that list of elements, no OR at hand. The fact that IUPAC or literature does not have a word or term for it, does not forbid us to list that set. For example, to state (in article) that "IUPAC has no name for the set of non-noble nonmetals". -DePiep (talk) 15:26, 13 September 2017 (UTC)

re "accepted [the IUPAC] standard for chemical communication": yes, if IUPAC actually has a standard in the topic. No when IUPAC says nothing about this. For example: the IUPAC Gold book does not mention metal, metalloid, nonmetal. Should we ban those words from chemistry then? No. We can use them (in chemical communication and in the encyclopedia), as described in literature. -DePiep (talk) 15:38, 13 September 2017 (UTC)

@DePiep: Your mentioned examples are widely used in chemical communication, the proposal is not used at all. EvilxFish (talk) 23:22, 14 September 2017 (UTC)

• @R8R: [4]

In short: it is the periodic table. Look for the PT trend, not the border issues. Poly/diatomic property is both correct, and ~useless.

Yes, the P infobox will say less active nonmetal — but wikilinked! That's still better than "other nonmetal", which would win your point. btw, I'd say the noble gasses are "not active". -DePiep (talk) 18:27, 10 September 2017 (UTC)

"Look for the PT trend, not the border issues." The beauty is in the eye of a beholder. You could easily distinguish the early transition metals (groups 3, 4, 5) from the late ones (groups 8 onward) and call it a part of a PT trend (which it is). Or you can say that the s-block is, trend-wise-speaking, one category. That being said, there are many ways to look at "the trend." It also appears to me that you are mixing the debate on whether we should have 1 or 2 categories for non-noble nonmetals and if should (in the latter case) go for "poly-/diatomic" vs. "active/less active."

It's interesting that this wikilink only redirects to Nonmetal. Perhaps one day this could be fixed, though, granted. Nevertheless, we here are facing a categorization problem and it should be no wonder that if a category name must have a meaning on its own: that's how you (should) categorize. This is a critical flaw I'm pointing at. (Also, of course, "other nonmetal" would never pass this.) So the current (weak) scheme is better than the suggested one, which I am genuinely sorry to say.--R8R (talk) 19:55, 10 September 2017 (UTC)

The (new) wikilink less active nonmetal is a redirect: Nonmetal#Less active nonmetal. Of course, that's User:Sandbh/Nonmetal_redraft#Less_active_nonmetal by proposal.

What I try to say is: when wikilinked (in that P infobox), less active nonmetal is not an idle wording (while "other nonmetal" likely is). After all, it is in a categories series. -DePiep (talk) 20:06, 10 September 2017 (UTC)

See OrganoMetallurgy's comment: you are trying to define "more and less" with wikilinks. This is a poor solution for a categorization problem such as this one. The division, should there be any, must come naturally; that's a prerequisite for any potential solution. Many many readers won't click those wlinks, by the way.--R8R (talk) 20:17, 10 September 2017 (UTC)

A "category name must have a meaning on its own": would be great, but only when available. Grouping s-block into one category can be done, but only if we can find a sole name for it? Would your point also object to "post-..." and "non-..." names? Even saying "noble (inert) gases" introduces the notion that there are elements that are not noble. In the periodic table, relative position is everything.

re "you are trying to define "more and less" with wikilinks". No, not defining. The wikilink leads to the clarifying (defining) page, as with any jargon.

Yes the solution is poor (but only relatively poor, I'd say). You're right that a division should come naturally. But isn't that what the sources do say, as the new article says? There is a natural, objective difference between say P and Cl. The issue that this border is not naturally hard and fixed does not negate that. Didn't we see & solve the same with metalloids, for example? Does that imply we should not classify metalloids? -DePiep (talk) 06:03, 11 September 2017 (UTC)

Whereas the other categories mentioned are widely used by chemists the proposed ones are not. EvilxFish (talk) 17:49, 13 September 2017 (UTC)

EvilxFish As an open question: what categories in the p-block do you prefer/propose/pursue? (Could cut things short). -DePiep (talk) 22:38, 13 September 2017 (UTC)

@DePiep: For p block elements, categories such as "noble gas", "metalloid" or "post transition metal" would have my full support as these are widely accepted and used in chemical communication. EvilxFish (talk) 11:04, 14 September 2017 (UTC)

That would leave some 11 elements that dare not be categorised because there is no name for it? At least they could be labeled "other nonmetals" (ouch), "leftovers", but more usefully is like "non-noble nonmetals" or "active nonmetals" as a descriptive category name which does not trespass into OR. The fact that there is not (yet) a widely accepted proper Name for it, does not mean the set does not exist as a set. (I assume that 'nonmetal' itself is acceptable too in your list). -DePiep (talk) 11:32, 14 September 2017 (UTC)

@DePiep: Of course there may be leftovers, it is not obligatory to force everything into a category, and if you look at things like this there is no attempt to deliberately force everything into a category. EvilxFish (talk) 23:28, 14 September 2017 (UTC)

Hi @R8R: From looking around it seems to me that category names do not need to have a meaning of their own. Examples:

• Greater scaup, Lesser scaup
• Little auk; Great auk
• Least auklet, Lesser kudu, Greater kudu
• Lesser bird-of-paradise, Greater bird-of-paradise
• Lesser Antillean macaw
• Less-active Mormon
• Weak force, Strong force
• Moderate breeze — moderate between what and what?
• Weakly typed, Strongly typed

Same questions arise but nobody's fussed: Lesser scaup? Lesser than what? Less-active Mormon? Presumably there are active Mormons? While the term transition metal is now well established, when it was first to refer to groups 8–10, its use would've—at first glance—prompted the question: transition between what and what? Yet there was no fuss. Sandbh (talk) 04:28, 11 September 2017 (UTC)

I see your point but I find that the analogy is a weak argument here.

First of all, the fact that these names exist is no proof that these are good names. "Weak/strong force" are in particularly poor as they are so general.

More importantly, all of these are not solutions for problems similar to this one. "Lesser bird-of-paradise" sort of implies that there is a greater such bird, and that there are two (maybe three) of these in total, so this counts as a proper name for a single entity (species). In contrast, we here are looking for a category names seeking to summarize the properties of various entities (elements). The discoverers get to name things they discover and they are not meant to be great namers. We, however, are dealing with a different problem of classifying the elements that have been there for centuries.

I think I have discussed the term "transition metal" before. It was a poor term when invented (or maybe context-specific) but it happened to be the term, and that is why it is okay now. I cannot imagine anyone thinks "active nonmetals" is the term rather than a term---until I am proven wrong, of course. But so far as this hasn't happened, I find this solution insufficiently good.--R8R (talk) 17:03, 11 September 2017 (UTC)

Quite relevant is that we are seeking a cover all once category scheme. We try to put each element into exactly one category. If it helps, you can think of three categories metals-metalloids-nonmetals. (We can leave the category-border issues aside; they remain available for those diving in the details). When using that 'cover all once' principle, relative-ness is implicit and all around: all categories are also defined against the others. When putting an element in category xyz, that also implies and states it is not in the other categories. From this, we find the name "nonmetals" meaningful and acceptable, even while it says "not-a-...". Relative to the other categories. If the categorisation were not covering all, stand-alone-categories and -names are highly required indeed. For example, coinage metals is such a grouping. No one wants to know about the non-coinage metals. -DePiep (talk) 19:10, 11 September 2017 (UTC)

• @OrganoMetallurgy: (10 Sept)

re "1. How "active" an element is is can be defined in numerous different ways, so it's a rather vague attribute". As with all categories, the category is based on a basket of properties, preferably containing both physical and chemical properties. For the active nonmetals, nonmetals (redraft) has wordings (I shortened): "Physically, gases/liquid/volatile solid; Electrically, most are insulators. Chemically, high ionisation energies, electron affinities, and electronegativity values; relatively strong oxidising agents, tendency to form predominantly ionic compounds with metals". I agree this leaves an arbitrary border, but not "vague". It's only "subjective" wrt to the weights applied (which can be published as science), not something like personal intuition. It would be extreme to use only one property; just to check: being a metal is a basket too, right? -DePiep (talk) 06:40, 11 September 2017 (UTC)

@DePiep: Yes, vague wasn't really the right word to use. What I meant was that "active" is a rather ambiguous term to use in this context. OrganoMetallurgy (talk) 17:11, 11 September 2017 (UTC)

@OrganoMetallurgy: Fair enough. Then, isn't the basket of properties (attributes) together pointing into the direction of "chemically active" (Even when incidental exceptions can be found). After all, the same happens with the (more general) metal category, and the metalloids category. Should we get rid of them for the same reason? -DePiep (talk) 06:28, 12 September 2017 (UTC)

re "2. ... still no clear divide ...". Agree. But that does not undo the spread in characteristics in the basket, and the possibility to discern two centers. A parallel. The same issue appears in listing the individual metalloids. The lists of metalloids shows 192 sources, each with its own argued list. Five elements are strongly disputed being metalloid (i.e., vague border issues). Should we therefor conclude: 'border unclear, so metalloids cannot be a category'? -DePiep (talk) 06:40, 11 September 2017 (UTC)

@DePiep: @OrganoMetallurgy: I think we should also acknowledge this categorization is not widely accepted and cannot be found in mainstream chemistry textbooks. Wikipedia is not the place for inventing new categorization schemes. EvilxFish (talk) 10:31, 12 September 2017 (UTC)

I think there's a significant difference between a category that most people use but isn't clearly established at the borders, and a categorisation whose names are not really well-established from the beginning. The latter needs to muster a lot more of a case before coming under consideration, methinks. Double sharp (talk) 12:31, 12 September 2017 (UTC)

• I note that most of the opposition comes from two factors:

  • opposition to the PT categories themselves - but this is out of scope for this RfC, which presumes that we have such categories and asks what is the best categorization scheme.
  • opposition to the proposed category names - but this does not take away from the significance of the categories themselves. Maybe it should prompt us to try harder to find better names.

  IMO, these are relatively weak arguments against the proposal.

  This proposal might perhaps have been stronger with the names "corrosive nonmetals" in place of "active nonmetals". I think this would have eliminated the N and P border issues. "Less active nonmetals" would still be sub-optimal, but in the discussion leading up to the RfC, we failed to agree on any better name. In retrospect, maybe "Weak nonmetals" might have worked at least as well, I don't know.

  The big lesson learned here: names matter!

  If this RfC fails to gain consensus support, I think our fallback position should be to group all 11 non-noble nonmetals together as "chemically active nonmetals". Although I originally argued strongly for that position, I am now very reluctant to go back there, as I have been convinced of a strong differentiation between "active nonmetals" and "less active nonmetals" along many dimensions.

  YBG (talk) 09:11, 13 September 2017 (UTC)

No, names don't matter that much. I disagree with the YBG conclusion about importance or category names. I think so far, the category names are not important in these objections and discussions. Nature does not stop just because we don't have a suitable name for it. The opposition can be traced back to: what's needed are strong, core categorising principles for those elements. Principles that create two clouds of elements, and that sets them well apart. When these are identified, category names easily follow. They can be either established names (not expected any more), descriptive names (as proposed, or more expanded), or simply listing names (like "non-noble nonmetals", or if everything else fails: listing the elements). So the problem is: find the strong grouping principles. -DePiep (talk) 15:19, 13 September 2017 (UTC)

@DePiep: I agree with all that you say, but I still maintain that category names matter as they are very helpful in gaining a consensus to accept a categorization scheme. This would not be an issue if we were in some sort of a command-and-control environment where a single person could decide and everyone else automatically fell in line. But this encyclopedia is organized by consensus, and in consensus building names and other non-technical optics make a difference in how and whether an idea is accepted. That is my only point in saying "names matter", and IMO that doesn't conflict with what you have written. YBG (talk) 21:41, 13 September 2017 (UTC)

The objection also stems from the lack of usage of these categories by chemists and Wikipedia not being the place for inventing new categorization schemes. EvilxFish (talk) 17:45, 13 September 2017 (UTC)

@EvilxFish: When you say "lack of usage of these categories", are you making a statement about these two categories or about he entire WP periodic table colorization scheme, including for example, post transition metals? YBG (talk) 21:41, 13 September 2017 (UTC)

@YBG: I am referring to the proposed categories, I have no objection to categorization in general when it is widely accepted in chemical communication. EvilxFish (talk) 23:25, 14 September 2017 (UTC)

I agree, EvilxFish "...lack of usage of these categories by chemists" &tc. That still is about the core of categorisation, not category names. BTW, I add, 'names are not important' also includes 'IUPAC naming is not all'. -DePiep (talk) 22:28, 13 September 2017 (UTC)

DePiep The proposal is to create particular categories and it is these categories I object to hence I oppose the proposal. I am not against categorization per say. Of course names are important one needs to communicate chemistry in an encyclopedia in the same way it would be found elsewhere. As I mentioned earlier Wikipedia is no the place for inventing new categories. Much love EvilxFish (talk) 12:10, 14 September 2017 (UTC)

These are not newly "created" categories. They exist in nature. The encyclopedia is intended to describe these existing facts, and with it we can use descriptive category names. Your limitation to those "one needs to communicate chemistry" is too narrow. If the description is sourced and correct, it has a place in Wikipedia. (The chemistry community including IUPAC then can decide to use it for communication or not). With this, for example "active nonmetals" is perfectly acceptable. -DePiep (talk) 13:21, 14 September 2017 (UTC)

One cannot separate things into chemically active/inactive categories in the same way one can't separate them into electronegative or electropositive categories as in fact a continuum exists. As for categories existing in nature I would argue categorization is a strictly human initiative however this is besides the point. Why would you want to create a new category that isn't used by chemists, has fuzzy boundaries and will add nothing to understanding on an encylopedia that is suppose to be based on Secondary sources? EvilxFish (talk) 23:19, 14 September 2017 (UTC)

@EvilxFish: "One cannot separate things into ... in the same way one can't separate them into ...". Agree. They are different classification systems. "as in fact a continuum exists": sure, but that continuum (or, more likely, points on a range spread, with intermissions) can be made into categories (as is already done with other, already accepted, categories). The true issue is to find clusters of elements on that continuum/range (there could be border issues, but that does not invalidate that clusters exist). Now, category "nonmetals" does exist this way, and also "noble gases" (aka inert gases). Since within the nonmetals we can identify & isolate convincingly those inert (or non-active) elements, the remaining group can can be identified too without OR. Descriptively, we can call those "nonmetals that are not an inert/noble gas", or "active nonmetals" for short; called "other nonmetals" elsewhere. And this is what exists in nature, the only human addition is that we point out & describe that category. (A next refinement could be into active/less active nonmetals, but at this point that seems to be a step too far, given that we even have to discuss the right to metin classess at all). -DePiep (talk) 10:37, 18 September 2017 (UTC)

One note about your line of reasoning. So far, you were arguing "not used in chemistry communication". But here it has shifted (widened) into: this categorisation is not allowed becasue of nature reasons. -DePiep (talk) 10:37, 18 September 2017 (UTC)

• Sandbh Typo, probably. "... behaves chemically more like aluminium in group 3" likely should be "... aluminium in group 13". Does not materially change the proposal. -DePiep (talk) 11:04, 29 September 2017 (UTC)
• re JonRichfield 11:48, 26 September.First some isolated remarks, then three overall.

"non-fundamental nature of ... classification ... chemically variable ... but ... an element is fundamentally a physical concept". That would throw all chemistry out of the periodic table, which is rather like throwing the baby with the bathwater. Why reduction the PT to physics (and only absolutely categorical physics at that)? For starters, oxidation state is the original and core tabuling principle, resulting in showing and supporting the periodic law; imperfections, irregularities, spots and all.^{[(Scerri, 2007)]} Physics only would lead to different PTs (left step), (adomah) — none have reached the basic textbooks. BTW, I could top the 'physical concept' with: actually, it's a mathematical concept.

Sure H can be seen as metal under certain circumstances, but why would that forbid us to use "metal" as a category? BTW: So "metal" has a definition in astronomy. That says we cannot use it in its earthly definition? Quite simply, and from astronomy too, we've solved another dual meaning this way: Mercury (element), Mercury (planet).

I don't understand why categorisation by chemistry would be unacceptable at all. Are categories like metal, metalloid, nonmetal irrelevant? Incorrect? Not used? Sure their borders are fuzzy (that is: borders only, no more than 10 elements at max), but that does nor invalidate nor disprove the categories.

Even more troublesome is the notion, mentioned by multiple editors here, that some categorisation is acceptable, often illustrated with, and limited to, the Recommended IUPAC names. As I quoted & analysed below in #The_IUPAC_Recommendations, IUPAC does not mention at all classes with unclear borders (only fixed elements lists; no metalloids then), and IUPAC does not describe the sets by quality (no: "what is alkali metal?" answers). IOW, IUPAC does not disallow (forbid) using other names explicitly (may we not use metal, metalloid, nonmetal concepts?) — it just does not mention them at all. Another recurring theme is "useful and acceptable" criteria for classes and their names. I don't think this science is about "usefulness" at all. Should oganesson be rejected from the PT because it can not be considered "useful" (Sorry JINR, next time try something else)? And being 'acceptable': that is what this RfC is asking! So now the question "Is this acceptable?", is answered with "depends on whether it is acceptable". While, available throughout and not mentioned at all so far: why not test for WP:RS, WP:VER, etcetera? That is our job at wikipedia. (In my own conclusion, later on, WP:FRINGE is introduced(!)).

TL;DR: 1. Chemical and non-absolute criteria may be applied to the elements. Especially since the periodic table principle has used and overstepped many such intricacies. Science, and so we, can very well describe such situations. 2. Classification is acceptable (and already done in RL), while not limited to the IUPAC Recommendations. 3. IUPAC Recommendations omit certain classes, but that's not a disallowing; it's a sign of doubtful border elements. 4. "useful and acceptable" are not the arguments to include/exclude anything wt this encyclopedia. RS is. -DePiep (talk) 09:35, 7 October 2017 (UTC)

• • I necessarily share Sandbh's trepidation in this discussion because the subject matter is extremely complex, whereas the ambition of this project seems to be for practical purposes to impose or at least to plump for an arbitrary classification. (Some of us will jib at "arbitrary classification", but it ultimately comes down to an arbitrary decision on which criteria within which limits we establish the descriptive taxonomy.)
    Now, DePiep objects to "useful and acceptable" as arguments for inclusion in WP, but they are essential to any material in any encyclopedia. If a term or classification or nomenclature or logical structure is not both useful and acceptable, then no reasonable person would want anything to do with it, decidedly including DePiep.
    And yet, all taxonomy more sophisticated than reference by ostention ("that one over there...") necessarily depends on variables in various dimensions. Of these, the most fundamental dimension in classifying chemical elements is atomic number, though of course, even there isotopes have implications, though less obvious than proton count.
    OK, so Mendeleef did us lots of favours by supplying another dimension beyond atomic number, pointing out in effect (though it took some time and a lot of progress to realise what he had in effect done) that electron orbitals around one or more charged bodies defined some new dimensions of behaviour that reflected coordinates in what we call periods and groups of elements. This in turn had emergent conceptual effects such as compounds and allotropes. And as we pass into the transuranics, we find still more new variables, such as the relativistic behaviour of orbital electrons and notionally solid noble "gases".
    Very well, suddenly all was light (if we ignore some of the subsequent sniping by traditionalists of the day who rightly found plenty of examples of anomalies that the naive theory did not account for) but then we ran into complications such as the overlap of energy levels of orbitals in successive periods, especially when one failed to account for temperature and pressure etc, and our simplistic early versions of the periodic scheme required modifications such as concepts of metalloids.
    It is neither helpful nor appropriate to caricature such recognition of realities with claims such as: "That would throw all chemistry out of the periodic table, which is rather like throwing the baby with the bathwater". It would be more like throwing out the bath as well. But it would be even messier to insist on keeping the bathwater, or to insist that there were no differences between the baby and the soap because we do not wish to throw out either of them; if not as chemists, then at least as encyclopedists, we would want our definitions to be meaningful in the sense that they distinguish objects or categories in ways relevant to the discipline in question; in other words that they are useful. This means that when working chemists routinely use terms such as "metalloid" and "alkali" we should discuss them whether IUPAC is interested in them or not. Otherwise, do we regard any reader looking up "metalloid" as stupid for asking such a dumb question?
    Patently groups and periods and atomic numbers are inadequate for general chemistry, though they are of conceptual use and form the basis of useful rules of thumb for everyday chemistry. Their predictive value actually that is of little interest nowadays; what is more important is their value in categorising elements. DePiep asks "H can be seen as metal under certain circumstances, but why would that forbid us to use "metal" as a category." No reason at all, but then if that classification is to be meaningful, the classification is not a function of the periodic table, but of the circumstances, and this is important to us. If we wish to have our classification reflect only the periodic table, then hydrogen is just another alkali – and another halogen, and the distinction between metal and non-metal would practically vanish.
    Conversely in practice no chemist would confuse the chemistry of C with Pb, so our task is not to classify elements naively according to the periodic table, but according to good sense within the periodic table. And the most practical classifications are fuzzy and are not a simple function of the groups and periods.
    This is not a new idea; Every textbook on chemistry in the last century or so has mentioned the exceptions and gradations and conditions, IUPAC or no IUPAC. The thing is to mention the various terms used for major subsets and the implications of the exceptions, not to sweep them under the carpet as "doubtful border elements"; there is nothing doubtful about them; they simply must be included in whichever category suits the context. In discussing the halogens we validly could include H and At in special senses as group 17, but for all normal purposes we unapologetically consider only F, Cl, Br, and I. In other senses we can include H and Ununennium in the alkalis as group 1, but more often we are quite content with Na to Fr (or even Cs). In short we must distinguish between the periodic table andthe realities of everyday practice.
    We also have to be extremely careful in WP to avoid imposing or even proposing rules; personally I am very sceptical of our constraints on synthesis, but for us to pronounce on the classification of any element as being in a particular group or as being a "doubtful border element", when there is argument about it, is definitely beyond our brief even as I see it. Even to quote IUPAC without mentioning dissenting voices when there is argument or special reason to mention reservation, (such as the varied use of "metal" and "metalloid") would not be good faith. I say: "Mention all the relevant terms and explain them in context or if preferred for the sake of concision, in linked, separate articles, but not as exceptions, only as emergent practical considerations. Sorry about being so long about it, but you now can see why I hesitated to reply at all. JonRichfield (talk) 08:03, 8 October 2017 (UTC)

re DePiep objects to "useful and acceptable" as arguments for inclusion in WP. That is because "acceptable" makes the question circular ('RfC: Q:Is this inclusion acceptable' A:'depends on whether it is acceptable'); being 'not useful' is not enough, and not encyclopedic: there is no "use" for oganesson so we should throw it out? By now, I can understand the rejections here for the proposed categories are WP:FRINGE, that is: giving undue prominence to an otherwise less important scientific statement (however correct and well sourced it may be). I don't support this RfC rejected just because categorisation is 'useless' (nor because it is 'arbitrary btw).

To talk about categorisation, I'll first use the top-categorisation this wiki uses: metals-metalloids-nonmetals, as these already show the main issues. (Their subcategories, ten as we use here, are either less controversial because being well-descript like noble gases, or are only showing more of the same issues). My main line is that this categorisation (metallicity into three categories) is applicable in the periodic tabler. Yes the exact member lists (and so borders in the PT) are disputed (which is not exactly the same as 'arbitrary'), but that does not undo the very existence of, say, metalloids, in the PT and in real life. Depending on circumstances (like temperature and pressure): sure, but therefor not unrealistic. Metallicity (and state, and standard atomic weight) can very well be described in 'normal' circumstances (Earthly environment), because that is how the elements appear to us. Then, in the individual articles, more extreme situations can be described (behaviour in extremely low temperatures -- fine). On top of this, the three categories make a fine, unbroken trend in the periodic table.

All this while I do not sweep "border issues" under the carpet, but I declare them less relevant, to be addressed in the articles (see metalloid). And no reason to remove categorisation in/by the periodic table. In other words: while there are category border issues (like disputed member lists, a mutual exclusion rule), that does not withhold RL science (especially chemistry) to apply categorisation.

Nor is the categorisation scheme we apply WP:SYNTHESIS. In 2005 #IUPAC Recommended a whopping 101 elements to be in named categories (not confined to group, block or period borders per se; introduced a border issue wrt group 12; and clearly kept the exception for hydrogen: in group 1, not an alkali metal). With this, it is perfectly OK to list "elements that are not labeled by IUPAC" for starters. And more can be sourced wrt metalloids or nonmetals, giving due weight to RS disputes. The fact that physically hydrogen is dual for PT purposes does not make it OR to actually put is in one of the arbitrary places.

JonRichfield applies this very strict rule for the PT: only categorical, absolute (and so physical only) properties are to be shown in the periodic table. However, the history of the PT is filled with arbitrary presentation forms to show a statement, almost all having to deal with exceptions (early swapping of elements to skip atomic weight order; positioning of lanthanides and actinides, irregular orbital filling). Still, those exceptions (or border detail issues as I call them) do not invalidate the statements made. The concept of metallic elements is not to be thrown out because of hydrogen. The suggestion that this metallicity is to be confined to chemistry articles only, and not be allowed in the periodic table (that should only be allowed for conceptual properties, once proven to be PT-related, I read) is not reflecting science, scholarship, and RL relevance IMO. -DePiep (talk) 12:32, 11 October 2017 (UTC)

The IUPAC Recommendations (IR)

There seems to be some confusion with regard to the status of "IUPAC confirmed" categories and names. To clean up, I'll quote and note the relevant paragraph from the 2005 Red Book. Bolding is added.

IR-3.5: ELEMENTS IN THE PERIODIC TABLE

The groups of elements in the periodic table (see inside front cover) are numbered from 1 to 18. The elements (except hydrogen) of groups 1, 2 and 13–18 are designated as main group elements and, except in group 18, the first two elements of each main group are termed typical elements. Optionally, the letters s, p, d and f may be used to distinguish different blocks of elements. For example, the elements of groups 3–12 are the d-block elements. These elements are also commonly referred to as the transition elements, though the elements of group 12 are not always included; the f-block elements are sometimes referred to as the inner transition elements. If appropriate for a particular purpose, the various groups may be named from the first element in each, for example elements of the boron group (B, Al, Ga, In, Tl), elements of the titanium group (Ti, Zr, Hf, Rf), etc.

The following collective names for like elements are IUPAC-approved: alkali metals (Li, Na, K, Rb, Cs, Fr), alkaline earth metals (Be, Mg, Ca, Sr, Ba, Ra), pnictogens (N, P, As, Sb, Bi), chalcogens (O, S, Se, Te, Po), halogens (F, Cl, Br, I, At), noble gases (He, Ne, Ar, Kr, Xe, Rn), lanthanoids (La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu), rare earth metals (Sc, Y and the lanthanoids) and actinoids (Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr).

The generic terms pnictide, chalcogenide and halogenide (or halide) are commonly used in naming compounds of the pnictogens,^{[The alternative spelling ‘pnicogen’ is also used]} chalcogens and halogens. Although lanthanoid means ‘like lanthanum’ and so should not include lanthanum, lanthanum has become included by common usage. Similarly, actinoid. The ending ‘ide’ normally indicates a negative ion, and therefore lanthanoid and actinoid are preferred to lanthanide and actinide.

— NOMENCLATURE OF INORGANIC CHEMISTRY
IUPAC Recommendations 2005, Red Book (2005) p51/pdf-p63

Notes on the Red Book

• For the current topic, we ignore explicit group names ('boron group'), block names (s, p, d, f), and the generic (compound) terms as sets. Also, we ignore issues like spelling and capitalisation (they do not alter the statements).
• IUPAC lists and names sets of elements, being 'like elements'.

"like elements" by IUPAC, labeled

Hydrogen

Helium

Lithium

Beryllium

Boron

Carbon

Nitrogen

Oxygen

Fluorine

Neon

Sodium

Magnesium

Aluminium

Silicon

Phosphorus

Sulfur

Chlorine

Argon

Potassium

Calcium

Scandium

Titanium

Vanadium

Chromium

Manganese

Iron

Cobalt

Nickel

Copper

Zinc

Gallium

Germanium

Arsenic

Selenium

Bromine

Krypton

Rubidium

Strontium

Yttrium

Zirconium

Niobium

Molybdenum

Technetium

Ruthenium

Rhodium

Palladium

Silver

Cadmium

Indium

Tin

Antimony

Tellurium

Iodine

Xenon

Caesium

Barium

Lanthanum

Cerium

Praseodymium

Neodymium

Promethium

Samarium

Europium

Gadolinium

Terbium

Dysprosium

Holmium

Erbium

Thulium

Ytterbium

Lutetium

Hafnium

Tantalum

Tungsten

Rhenium

Osmium

Iridium

Platinum

Gold

Mercury (element)

Thallium

Lead

Bismuth

Polonium

Astatine

Radon

Francium

Radium

Actinium

Thorium

Protactinium

Uranium

Neptunium

Plutonium

Americium

Curium

Berkelium

Californium

Einsteinium

Fermium

Mendelevium

Nobelium

Lawrencium

Rutherfordium

Dubnium

Seaborgium

Bohrium

Hassium

Meitnerium

Darmstadtium

Roentgenium

Copernicium

Nihonium

Flerovium

Moscovium

Livermorium

Tennessine

Oganesson

• In this text, 101 elements are explicitly listed being in a 'like elements' set. Eleven sets are named (there are overlaps).

• All sets mentioned have a fixed list of members (except for the transition elements, where group 12 elements Zn, Cd, Hg, Cn may be excluded: i.e., an explicit border issue).
• IUPAC gives names for all 'like element' sets
• IUPAC does not define their like-ness (no set definition, not 'what is an alkali metal?').
• Not listed, not named sets: metals, metalloids, nonmetals. I note that these sets do not have a definite list of elements. Simply by looking at the metalloids, which is clearly not a definite set in literature, introduces border issues (element inclusion yes/no?), and thereby fuzzing the borders of all the other sets (who are bordering metalloids). The non-listed like-sets are in or near the p-block.
• Also not listed, not named (subsets): post-transition metals, non-noble nonmetals, 'other nonmetals'. Here too the metalloids' border issue rules. Also not mentioned are wiki category names polyatomic nonmetal, diatomic nonmetal, less active nonmetal, active nonmetal.

-DePiep (talk) 13:32, 29 September 2017 (UTC)

Red Book Conclusions

• IUPAC identifies sets of 'like elements'.
• Sets that are Recommended by IUPAC have a fixed list of member elements.
• IUPAC gives names to all these recommended sets.
• IUPAC does not define the nature of a like-ness (no description of what makes an element being an alkali metal).
• Possible sets that have no definite element list are not mentioned, not names, not listed. This includes major sets metals, metalloids, nonmetals. Also subsets that border the metalloids are not listed. IUPAC does not say anything on these unmentioned sets. This also implies, there is no dis-recommendation.
• So for this RfC: while IUPAC does not mention the proposed categories, that does not prove any disapprovement. It's just: no fixed element list, so not mentioned and not recommended. This also, exemplary, applies to the major metal–metalloid–nonmetal category names, elements lists and definition.

-DePiep (talk) 13:32, 29 September 2017 (UTC)

Infobox element: Spectral lines images

1. I have created the overview list {{Spectral lines of the elements}}, now live in spectral line. It uses {{Infobox element/symbol-to-spectral-lines-image}} (with some 30 image names at first).

2. {{Infobox element}} now reads the image name from that list (so, not added as a parameter into {{Infobox aluminium}} any more). Also, it shows in header "Physical data", not as a second image. (|image 2= is deprecated and does not show any more). Example: helium. When no image is in the list, nothing shows (vanadium).

• Considerations. Some months ago we discussed removal of these spectral images. That did not take off. However, my then argument that this image is not important enough to be the second image in top, still stands (per WP:INFOBOX). Also, recently the parameter standard atomic weight was moved up into General properties because atomic weight is "so important it must be close to the top", "the fundamental importance". This implies that other properties must be less important, and should be moved downward. Plus, of course, that it is impossible to put everything in top.

• Maintenance. {{Infobox element/symbol-to-spectral-lines-image}} now has some 30 images (26 were in the infoboxes). The list could be expanded by searching commons c:Category:Atomic spectra. I think it's best to use the "visible" images (=in the visible spectrum only) when available.

In the table {{Spectral lines of the elements}}, it shows that not all images have the same ratio (w:h). They could be cropped I guess.

Maybe the showing in the infobox needs tweaking (position within Physics section, size, ...). Ideas? -DePiep (talk) 14:21, 10 September 2017 (UTC)

 Done added all available images up to & including E99 Es. Missing: At, Fr. Same name pattern "Einsteinium spectrum visible.png", same source (creator), so all ratios are equal. -DePiep (talk) 16:03, 10 September 2017 (UTC)

I agree that this doesn't need a place of honour in the infobox; without actual numeric values for the wavelengths it is just eye candy, but with them the infobox suddenly triples in size at least (and what to do with something like Fe?); leaving these in a data page seems the most sensible. Double sharp (talk) 02:31, 11 September 2017 (UTC)

How does it "triple in size"? As for image height: yes, I'd like to have that halved at least. (And I object creating data pages). -DePiep (talk) 05:41, 11 September 2017 (UTC)

What's the problem with Fe? And btw, the large height comes with all "... visible.png" images, i.e., from the same source. -DePiep (talk) 06:45, 11 September 2017 (UTC)

Each individual line in the spectrum corresponds to a specific wavelength of light. The exact values of these are important (e.g. H-alpha), but you cannot possibly put all of them in (one for each line), because there are far too many of them: Fe is just an example where this is the case. The CRC handbook likely has the numeric values. From the image it is pretty much impossible to extract out this information, but without it the spectra merely "look cool" without really saying much. (Also, surely they are atomic properties, not physical properties?) Double sharp (talk) 06:59, 11 September 2017 (UTC)

Got it. We'll see if people want to include the (CRC) wavelengths in enwiki, and where (not in the infobox I claim ;-) ). Can move it easily into Atomic data, just suggest a row position in there. Into Misc also possible. -DePiep (talk) 08:18, 11 September 2017 (UTC)

I don't think there is a problem with something like spectral lines of the elements (data page). That way the info is there if you really want it that badly (and we continue making the CRC handbook obsolete ^_-☆), but it doesn't clutter things up in the infobox. Since the data in the picture is this obscured, I think somewhere in "Miscellaneous" is actually a better choice; the exact position within this section does not matter very much to me. Double sharp (talk) 06:54, 12 September 2017 (UTC)

OK, noting that Spectral lines of the elements will do. I'd object to [[Carbon (data page)]]. -DePiep (talk) 16:02, 13 September 2017 (UTC)

• I'm working on reducing the image height, and move it to "Atomic data". Article creation as mentioned is open. BTW, are the images clear enough? I'm having trouble seeing some lines different from the background continuum. -DePiep (talk) 06:52, 20 September 2017 (UTC)

 Done, see hydrogen. Moved to Atomic data section, reduced height, use caption. (mobile view can be too better: center, rm extra newline). -DePiep (talk) 12:08, 28 September 2017 (UTC); done mobile view too. -DePiep (talk) 12:38, 28 September 2017 (UTC)

Looks great! Double sharp (talk) 15:03, 3 October 2017 (UTC)

PT nav sidebar

The {{sidebar periodic table}} has a header "Period table" and a pre-header that says "Part of a series on the", with "series" wikilinked to category:Periodic table. This wording is similar to these navigation sidebars:

• {{Chemical agents sidebar}}
• {{Politics of Pakistan}}
• {{Politics of Croatia}}
• {{Administrative levels and divisions of China sidebar}}

The "series" wikilink is similar to these sidebars:

• {{Hindu scriptures}}
• {{Jews and Judaism sidebar}}
• {{Anarchism sidebar}}

These are some of the examples I followed in trying to come up with a good sidebar format. Recently, DePiep removed the pretitle, resulting in this version. By WP:BRD, I have restored the pretitle (here) and am here inviting comments as to whether the pretitle belongs or not. I have a preference, but not a super-strong one, but I do think it merits a bit more thought. Comments anyone? YBG (talk) 23:45, 11 September 2017 (UTC)

Seems to be habit in these sidebar (even parameter |pretitle= is available). However, elsewhere we do not expand titles like:

Paper title is not "This article is about paper"

Navbox title (blue box at bottom) is not "This is a navigation tool for paper"

Section titles are shortened: its "Paper#History" not "Paper#History of paper". Will have to dive into this at {{Sidebar}} and WP:TITLE MOSes. -DePiep (talk) 06:34, 12 September 2017 (UTC)

Consistency is a virtue, so I would reluctantly support the pretitle. However, DePiep's argument is very convincing, and leads me to think that none of these sidebars should actually use the pretitle (but good luck convicing everyone on every page involved). Double sharp (talk) 06:52, 12 September 2017 (UTC)

Improve table in main article

I propose using File:Simple Periodic Table Chart-condensed.svg (or File:Simple Periodic Table Chart.svg; but first one is better, improved) instead of File:Simple Periodic Table Chart-en.svg. All three files are created by same user.

Current file has ugly big arrows, bigger than the text next to them + it is not clear what designation is for what arrow (it can be misunderstood that "Period" is for rightwards arrow and "Group" for downwards one). Other reason can be that in current version notations are expanded and translation is thus harder (Inkscape must be used, text deleted by nods manually and new one put and expanded – what cannot be done in a way that alignment stays same to the original etc.); in updated version <switch> is used and translation is very easy (in Notepad or other text editor).

There are no changes in color scheme, placement or anything (only cell edges are with rounded corners and without border). I was bold and updated image myself because there were no content changes (only style) but edit was reverted by same user who changed file to match color scheme for which consensus has recently been achieved but still without clear consensus for image itself. --Obsuser (talk) 21:26, 14 September 2017 (UTC)

I was the editor that reverted [5]. I also went to your talkpage to invite you editing in cooperation [6]. I do not understand your last paragraph here, please rephrase.

As I said in the diffs, in the periodic table the editorial style is content too. That is, editorial changes (or improved design as it you described it) should be scrutinised by scientific (chemical, physical) meaning too. Here I add that we (at WP:ELEMENTS also put loads of effort in keeping all periodic tables, (and parts thereof) whatever they depict, using the same style.

For example, using a blue background color for table-structural parts (group numbers) is not helpful for the reader. I have no idea why Offnfopt keeps forking variants without consulting this WikiProject, while they were advised to do so. Whatever, these variants are not to be used on enwiki, and Offnfopt is doing the enwiki and interwiki community a great disservice by creating unsupported unsollicited variants. It is incorrect to say it all is an "improvement".

• The improvement, as already noted, that would be helpful is adding the language switch. If the svg-technical issues (related to Inkscape if I understand you well) can be removed without interface effects (i.e., resulting in the same table visally and in behaviour), that would be fine too. Removing the borders and even rounding the squares is not an improvement. You are welcome to propose improvements wrt the two arrows. -DePiep (talk) 21:58, 14 September 2017 (UTC)

User:Offnfopt Talkpage detail

Moved from User talk:Offnfopt

 – Offnfopt^(talk) 04:02, 15 September 2017 (UTC)

See WT:ELEMENTS. I see that you have forked the poriodic table in unsollicited, unconsulted variants. It surprises me that you continued to edit this way, alone, after I explained the situation to you at the GL. To be clear: uncooperated variants and edits are not helpful (for the reader, for the interwiki, the enwiki community and for our encyclopedia). Once more you are invited to work on improvements in cooperation, in this case through WT:ELEMENTS. -DePiep (talk) 22:07, 14 September 2017 (UTC).

DePiep I am not required to get your permission any time I want to create a new image and upload to commons. I kindly ask you to disembark my talk page and not to get in contact with me again other than through article talk pages and only in regards to edits to a specific article I may have made that needs discussion. When it comes to uploading new images to commons, I do not need your authority or your permission. After the way you handled the first instance of me helping you, don't expect me to do you any favors any time soon. You can't treat others poorly when they help you out then expect them to help you a second time. Please don't further contact me. - Offnfopt^(talk) 23:48, 14 September 2017 (UTC)

I am not required to get your permission: Agree. Where did I say so?

disembark my talk page sure, there is a rule you can request that. Can't find it now.

not to get in contact with me no, won't happen that way. This is Wikipedia.

Please don't further contact me No, can try but can't promise. For example, to reply to you seriously I do ping you now, from a WP talkpage: Offnfopt. By the way, do you know how Wikipedia, and Wikipedia editors, work? At all? How is a "don't contact me" supposed to n out here?

-DePiep (talk) 21:17, 15 September 2017 (UTC)

Offnfopt, I asked for a change at WP:Graphics Lab. Instead, you created a new version with the change, without changing the target image. I wrote disappointment, asked to change the original one too, and noted that your version (being svg) had prospects in other situations. I also wrote that style changes, and creating a second same image (forking), was not helpful in our set of periodic table images & templates. For example: we are very carefully choosing & using background colors, then consistently use them all around. Another example: in PT interwiki & i18n we don't want to add unmaintained images, because other places may use the wrong or outdated version unknowingly. I also invited you at GL, as I did on your talkpage quoted above, to join the coordination and cooperation wrt the enwiki Periodic table images by entering talks here at WT:ELEMENTS. Cooperation is needed simply because the periodic table is spread over many images and templates, over many css-styles & wikis, and over many content issues; also multiple editors are involved. After all this, consensus is the keyword (I can tell that produced a high quality level of enwiki articles/images, and it is very rewarding).

It's a pity you don't want to be involved, especially given your skills, but as far as I am concerned you are still welcome here. -DePiep (talk) 08:09, 16 September 2017 (UTC)

Group names: stress old A/B name patterns

In Group, we also list the old Roman + A/B numbering systems ('US', 'European'). To stress the pattern in either system, and the difference between the systems, I propose to add A/B colors in the overview table here.

Background. Both patterns have a rationale in the system. The patterns are: either -B are the d-block groups (US), or -B are the second appearance of the valence number (righthand side in a period; Europe). Historically, Mendeleev had put both valence-series (I–VIII) below each other (Mendelejevs periodiska system 1871). Note that Reihe 1 and 2 are today's period 1. When people moved each second row to the left, creating the repeated valence group numbers, A and B were added. (BTW, this is the origin of the "short form" and "long form" graph descriptions; later this got more confusing as the lanthanides and actinides had to be accomodated in extra columns). -DePiep (talk) 11:14, 16 September 2017 (UTC)

Comments? Tweaks? -DePiep (talk) 11:14, 16 September 2017 (UTC)

Here's a few ideas to consider. Each can stand by itself or in any combination with the others.

Note: (a) indicates status quo options; * indicate the current sandbox options

1. How many colors: (a) none, (b) one (just B's) (c) one (just A's) (d)* two (A's & B's)
2. What to color: (a) nothing, (b) A/B letters only (c)* Full group designator
3. Normal vertical alignment: (a)* all top (b) vertically center 1st 4 rows (1-18, I-VIII, A-B-A, A-B)
4. Emphasis vertical alignment: (a)* none (b) top align A's, bottom B's, center VIII & Group 0.
5. Bold face: (a)* none (b) bold face the letters, as IIA and IIB
6. 1st cell in row: (a) Include "A-B-A" and "A-B" (b)* Eliminate "A-B-A" and "A-B"

I'm not sure which of these 192 combinations (4×3×2×2×2×2) I prefer.

I find the colors a bit distracting - hence 1(b) and 2(b) suggestions - but I realize that vertical alignment 4(b) suffers the same issue, just in a different dimension.

Thanks for bringing this up. This groups template, IMHO, is considerably less attractive than virtually all of our other PT-related templates. YBG (talk) 13:39, 16 September 2017 (UTC)

I like the sandbox version; it delivers the information very directly. Double sharp (talk) 16:19, 16 September 2017 (UTC)

Two replies:

General attractiveness of the table

• re YBG: considerably less attractive. Well, let's spend some time on this then!

Could you be more specific? Of course, the sole aim of the table is showing the group names. That differs from most other PTs (who are mainly element-oriented). Because of this goal, the groups (columns) must be stressed; currently: by zebra pattern grey/white. This be stronger? Also, the names must be clear and standing out (now: six rows). Should we uncolor the elements (or: much lighter/greyish)?, since the category colors distract.

For me (in my screen), the template is very wide or too wide, and so I crammed the info, horizontally. Any other suggestions? Am I designing for the wrong screen? How is it on mobile view?

Marking As and Bs

• re YBG: thanks for the options, now please share your thoughts & considerations ;-): do we want to mark them at all, and what to achieve, and then: how?

Current colors are: IIIA, IIIB They work great vertically: the altering shows (IIIA in US, IIIB in EU)! They do not work good enough horizontally: the pattern rationale, as I described above, is not easily recognised (at all). I ponder putting my ~text in an article-section (History).

Done: I moved these two rows downwards, to separate them visually from the other four rows (and: they are old names anyway). Note: also available: a neutral color, like in group 0. I saw no need to use it btw.

1: "number of colors to use": use two colors, maybe three. A and B are equal, not of different importance. And removing just one color does help what?

2: "what to color": full group (including the Romans), Romans are part of the problem. To stress the whole IIIA/IIIB conflict, twice even. Not just the A/B conflict in there. (See no gain in coloring the whole cell).

3, 4: "vert alignment": to what improvement? Rows are good for reading, including the rowheader. Keep in top of cell.

5: "use bold A, B": No, bolding does not help showing the differences (contradictions in IIIA/IIIB)!

6: "Include/exclude ABA/AB pattern in rowheader": don't know, it's just an awkward place to explain or even hint their patterns (better: more in text, next with the colors).

That reduces the options to 2x1x1x1x1x2=4; −188 ;-).

7: I add: tweak AB colors (lighter; could reduce attention wrt other name rows).

8: I add: tweak category colors (lighter, greyish, grey only, extend use column zebra color). That reduces their attention seeking and winning.

Now it's ~16, including two tweaking range researches todo.

I'd say: current sandbox could go live, provided: a. add legend to the table; b. add textual section like History.

-DePiep (talk) 18:34, 16 September 2017 (UTC)

Given this menu of choices, here's my offhand preferences, which I note do not agree with yours.

• 1(b), color only the B's - one color makes it easy to use a neutral color that doesn't conflict with the metallicity colors.
• 2(b) color the A/B letters only, this emphasizes what we are trying to emphasize. The eye can already easily see that the Roman numerals are identical in the two schemes
• 3(b) vertically centered cells are much more attractive, at least when all cells have the same number of rows
• 4(a) don't use vertical alignment to emphasize A/B differences
• 5(b) bold face letters also help to emphasize the A/B distinction
• 6(a) restore the A-B-A and A-B to the 1st cell in the row.
• 7: No opinion on change in colors
• 8: Leave metallicity category colors unchanged
• 9: Move the A-B-A and A-B rows back to their previous location. Having them next to the other numbered group names provides context.

But I think the underlying problem with the chart has to do with the fact that the trivial name row and the name-by-element row are jagged, some cells with two lines of text and some with three.

One way to change this is to completely rethink the table. Have one row per group, with six columns ccorresponding to the first six rows of our current table. Then add a seventh column with a micro PT with the group in question marked. This I think would be much more attractive than either the status quo or the sandbox. We should first try it without any special color markings for A/B and then evaluate whether something is needed to emphasize the different A/B patterns. I'm busy right now IRL, or I'd mock it up myself. YBG (talk) 22:09, 16 September 2017 (UTC)

YBG: why do you restart from zero (again)? Why do you not reply to my responses, and create a line of thoughts? And again your are questioning the overall setup, without making steps forward (and still mixing up the issues I separated for you; a needless confusion). I repeat my earlier question to you: "do we want to mark them at all, and what to achieve, and then: how?". A very frustrating development, YBG. I don't feel invited to spend more time on this. -DePiep (talk) 00:19, 17 September 2017 (UTC)

I laid out a number of alternatives, without giving my preferences, because I hadn't really settled on them, and hoping that at least one of them might meet with your approval or at least spur you to more thought. I then read your responses, which seemed to reject most of my ideas (not because they weren't your ideas, but because you didn't think any of them an improvement). I did seem to spur you to more thought, so at least part of my purpose was accomplished. Then having had a bit more time to think about it, I then listed my preferences and my reasons, which were quite different from yours, but I trust you will AGF that it wasn't because I was rejecting any ideas because they were yours, but because my stylistic preferences and aesthetic sense are different. I had no intention of frustrating you nor of making you feel unwelcome. As far as separating ideas and mixing issues, it seems to me that our thought processes work differently than yours, and I trust that you can find yourself able to accept the fact that not everyone thinks about things the same way. Anyway, after I went through all of that process, I had an 'aha' moment and came up with an entirely new and different idea of how to structure this template. I am now working on a mock-up and hope to have it ready for view sometime in the near future. Your ideas and your quewstions are always thought-provoking and I appreciate that and thank your for it. YBG (talk) 00:47, 17 September 2017 (UTC)

PT groups template - a different approach

The above discussion led me to consider a completely different approach to {{periodic table (group names)}}. I have mocked up a first try at here. I'm not satisfied with the results, mostly because the {{periodic table (32 columns, micro)}} takes up too much room. However, if this approach to the groups template seems worth pursuing, some we modify {{periodic table (micro)}} and {{periodic table (32 columns, micro)}} to accept and pass in parameter(s) to {{periodic table (32 columns, micro)/elementcell}} in order to modify the one or more of the three places where the size is specified with a *px value. Or, since I think we could safely dispense with the hyperlinks, other simpler approaches are possible. But first things first: Does anyone else think this approach is worth pursuing? IMO, this table is much more attractive than the current one we are using. YBG (talk) 02:46, 17 September 2017 (UTC)

Many of my expectations about this idea were borne out by the mock-up. But I had two big surprises:

The PT was bigger than expected, making the rows taller. Henc my suggeson above to size the non-text PT parametrically.

Scrolling down and seeing the group markings march through the PT from left to right, almost as if it were an animated GIF.

Anyway, I await comments from other WP:ELEMENTS participants. YBG (talk) 14:58, 17 September 2017 (UTC)

I wonder: why aren't Ts and Og showing up as members of groups 17 and 18 respectively? I think that this is perhaps too repetitive, what with eighteen separate periodic tables all marking one column or another; surely the point is made rather quickly? Double sharp (talk) 15:25, 17 September 2017 (UTC)

(Solved; in the micro PT, they had wrong group nubmer). -DePiep (talk) 16:49, 21 September 2017 (UTC)

• Wow! This is daring! Transponing all the columns like it's eight-teen six-ty-nine.

Listing the columns/groups vertically must have a very, very good reason. Because there is the a priori issue: readers think & associate columns with being arranged horizontally. When listed vertically, as proposed, for each and every reading the reader has to make this mental step: "this is about a vertical thing". This is both about the reading (textual stuff) as the overview (glancing at the page). So there must be a good reason to introduce that step.

But I did not see or read one reason for this, so far. Even worse: from the start it is about space only. The fonts are reduced (why at all), and complaint is that the micro PT is too large. Size only. (BTW, the micro table being the one good thing in here, because greatly it has that vertical description thing). Above I already mentioned that it is crucial to keep & stress the vertical column-aspect of groups (today the zebra coloring), at least to cancel the shouting individual element's colors & attention.

So, the primary and unanswered question is: why transpone the table (swap columns into rows)? All other questions, those surviving, are details to be dealt with later.

TL:DR; listing columns in a vertical list is a step back, because the (implicit, mentally present) association is broken at every page glance & text reading. While no gain is shown or mentioned. -DePiep (talk) 20:03, 17 September 2017 (UTC)

Re why transpose: IMO, this list has too much info to be clearly and neatly presented in 18 parallel columns.

Re horizontal/vertical: I agree with DePiep that it's generally best to list vertical things vertically and horizontal things horizontally. But we don't always follow this. I've seen many tables where the column headings are explained in a (vertical) bulleted list at the beginning or at the end of a table. I generally don't like this, but it is sometimes helpful. For example, both {{navbox periodic table}} and {{sidebar periodic table}}, show periods (a vertical thing) in a horizontal list.

Re unnecessary repetition: I repeated the micro PTs for the reason that DePiep deduced - to emphasize that we're discussing PT columns.

Re font size: I'm not hung up on the text size, but I do think it would be good to make the PTs smaller so that more of the table can be seen at a glance.

Re TL;DR: @DePiep, are you saying that my talk page post was too long? Or that the sandbox itself? As for the latter, that is why I'd like to use a smaller version of the micro PT. YBG (talk) 21:16, 17 September 2017 (UTC)

re Re why transpose: As I described, this is not strong enough to abandon column order in the first place. Some info could be removed or replaced (I already did some), but more importantly: I find current live setup the most effective presentation of the information available. "clearly and neatly presented", is not just my opinion but my reasoned opinion. For example: while six rows of group names are presented, all have a most regular justification (wrt left & top) & relative position (name comparing).

re Re horizontal/vertical: ".. s generally best to list vertical things vertically and horizontal things horizontally. But we don't always follow this.": WP:otherstuffexists, sure. But that is not an argument. I do simply turn it around: probably those other examples could use a change for reasons I mentioned.

re Re unnecessary repetition: Yes vertical is good and I asked for it, but you introduced the need for repetition(!) which I do not advocate of course. You took out the verticalism in the first place, by laving the in-column presentation.

re Re font size: not that important, but I thought: why?

re Re TL;DR: this YBG reply does not seem to refer to the TL:DR; I wrote.

Once more: leaving the column structure is a drawback in glancing (overview) and reading (finding textual info). Current version smartly, intuitively supports its info by using the existing columns. While OTOH in the YBG proposal this only returns in the micro PTs, which have to be repeated 18 times. Even if they are reduced to a 50% size (which would virtually eliminate their clickability & readability), even then the listing is large not for exact size but for being this repetitive. -DePiep (talk) 17:12, 21 September 2017 (UTC)

Alkali metals: not an IUPAC group name

For example in Group names, it states that group 1 is named alkali metals (IUPAC approved), and Hydrogen (H), while placed in column 1, is not considered to be in the group alkali metals. This is how IUPAC defines the "alkali metals",

"The following collective names for like elements are IUPAC-approved: alkali metals (Li, Na, K, Rb, Cs, Fr)". (IUPAC Red Book (2005) p. 51/pdf-63)

So yes those are the alkali metals, but no it is not defined as a periodic table group (column). This conclusion should lead to removing that statement in there (never say "The alkali metals group"). Also, there is no use in keeping that as a group name with an elaborate footnote required at every use.

However. The alkalis still remain, even stronger maybe, a category in metallicity as used in this enwiki. More such categories exist without following group or block borders. -DePiep (talk) 11:17, 18 September 2017 (UTC)

In practice, the status of hydrogen as a group 1 member is equivocal enough that these are not necessarily in contradiction. Both Greenwood & Earnshaw and Holleman & Wiberg (standard inorganic chemistry texts) do not consider hydrogen to be a group 1 element. I know the IUPAC periodic table says that it is one but it is so different that this is generally ignored. Double sharp (talk) 12:09, 18 September 2017 (UTC)

Hydrogen placement is not the issue, and does not alter the non-claim. Point is that IUAPC does not state "group 1 = alkali metals". So we can just remove that, without introducing an error. This is correct independently of H placement. BTW, do the two source both actually state that "group 1 = alkali metals"? -DePiep (talk) 16:38, 19 September 2017 (UTC)

Yes, because they do not consider H to be in group 1. Hence the elements they put in group 1 are only Li, Na, K, Rb, Cs, and Fr: exactly the alkali metals. Double sharp (talk) 23:27, 19 September 2017 (UTC)

Ok, here is one exact quote from Greenwood and Earnshaw that I had trouble searching for on my phone (p. 74): "The Group 1 elements are soft, low-melting metals that crystallize in bcc lattices." This cannot include hydrogen, which is neither a metal nor crystallises in bcc lattices, but is correct for Li, Na, K, Rb, and Cs (and predicted to be so for Fr). Additionally, searching for "Group 1" in the index directs you to "see Alkali metals", just as searching for "Group 2" gives "see Alkaline earth metals" and "Group 0" gives "see Noble gases". Double sharp (talk) 23:43, 19 September 2017 (UTC)

Yes, this is a correct deduction. And no, this is not a source to claim that IUPAC nor G&E do define group 1 being alkali metals. And note: nothing is lost anywhere when we remove the statement "group 1 = alkali metals", all texts keep working (including G&E). -DePiep (talk) 10:17, 23 September 2017 (UTC)

• This is getting silly. (1) IUPAC does not define it that way, so we can not state that it is IUPAC-defined. (2) G&E uses the congruence in nicely, but has no issue with it. (3) There is no gain in keep repeating such a statement in this wiki, with otrr without adding an elaborate footnote that is required becasue of makeing that statement in the first opplace (iow, makeing the statement introduces the need for a footnote in the first place, while omitting the claim solves this). I propose removing the statement "group 1 = alkali metals", for being not sourced. -DePiep (talk) 10:17, 23 September 2017 (UTC)
  • I am OK with deleting "alkali metal" as a group name for group 1, but I think it would be helpful to still add a footnote like "Hydrogen is sometimes excluded from group 1; the remaining elements in the group are termed the alkali metals". This "abuse" of the term "group 1" is a bit too widespread to let it go without explaining it in a sentence, IMHO. Double sharp (talk) 12:41, 23 September 2017 (UTC)

OK with me. Sometimes in-text notice may be even nicer & more readable, instead of a footnote. In a table or infobox only when it is relevant (versus cramming info) I'd say. -DePiep (talk) 06:47, 28 September 2017 (UTC)

Long post re (gasp!) other nonmetals

Initial post by Sandbh

Posted here for project members rather than the broader RfC audience.

Colleagues, my impression at this point, and subject to your views, is that the RfC should be closed due to consensus not being obtained.

I’ve thought long and hard about what happens next.

I now propose, as per @R8R:’s preference, that we have only two categories of nonmetal:

(1) a placeholder category of "other nonmetal"; and

(2) a noble gas category.

Yikes! Not other nonmetals again! I know, I know: please read the rest of my post carefully before making a judgment about this term.

Importantly, this proposal is consistent with (a) the example given by EvilXFish, i.e. PT.com which is the top rated Google result, and (b) the Encyclopedia Britannica. I also recall that all project members apart from me were happy with a single non-noble gas nonmetal category.

In our colour category table the name other nonmetal would be used only to avoid the need for a more cumbersome collective term such as "non-noble nonmetals", or "nonmetals other than noble gases", given there is no widely-used proper alternative category name, including "chemically active nonmetals", which is the point made by those who opposed my original proposal.

Since "other nonmetal" is a placeholder name rather than a proper taxonomic category name, there is no real further need for its use in the singular. For example, chemists usually refer to group 14 as comprising carbon, a nonmetal; silicon and germanium, metalloids; and tin and lead as metals. The fact that lead is a post-transition metal is convenient when discussing this particular category of metals as a whole but it is otherwise not usually needed when speaking in general terms. Same goes when one refers to "nonmetals": the presumption is that someone is referring to nonmetals other than noble gases, unless they have specifically referred to the noble gases. However it is convenient when you want to talk about the non-noble nonmetals to be able to refer to them collectively as other nonmetals. And the other nonmetal name would still show in the info boxes for the applicable elements.

The comparison of properties section of the article would then have three rather than four columns: one for metalloids (given their nonmetallic chemistry), one for other nonmetals, and the last for noble gases. The other nonmetal column could be split into two with a dotted border between them (i.e. to indicate that the border is not always sharp). One sub-column would be for H, C, N, P, S, Se; and the other for O, F, Cl, Br, I, in order to show the contrast between the two subsets of nonmetals, noting neither half of the column is named. The blurb introducing the table will explain the basis for this semiquantitative treatment i.e. oxidising power; covalent v ionic bonding tendencies with metals: corrosive behaviour; ionisation energies, electronegativities, electron affinities, and simple anion formation.

This approach is an attempt to highlight and preserve the interesting progression of nonmetallic character seen in the vicinity of the nonmetals, and to make the nature of the seemingly rag-tag collection of the nonmetals in the other nonmetal placeholder category more transparent. I hate obfuscation, which is what the placeholder category of other nonmetals usually conveys.

I know the term "other nonmetal" is unpopular but as an encyclopaedia we have insufficient leeway.

In summary, I am trying to accomodate as best I can the views of both camps i.e. those who supported and those who opposed the original proposal, and clarify a good amount of realistic complexity (namely the omnium gatherum that is the other nonmetals) without misleading anyone.

@R8R:, @Double sharp:, @YBG:, @DePiep:, @Parcly Taxel: I ask that you consider this proposal carefully and to please not get unduly concerned about the name "other nonmetal". It is not a real category, only a placeholder for the rest of the nonmetals. Despite the "resting place" connotations of the term, there are still some interesting observations that can be made about nonmetals in this space.

We did talk about calling the two categories "nonmetal" and "noble gas" however this is cognitively dissonant (does it mean noble gases are not nonmetals?), unless you happen to look at the legend. And the legend boxes for the periodic table in the top right of the nonmetal article would presumably have to read "Nonmetal" (other than noble gases), and "Noble gas".

I recall that an "other nonmetal" category appeared on our periodic table for many years, with no controversy until I stirred things up. Mea culpa. In retrospect I agree with R8R that the poly-di categories were a split for the sake of having a split. I see no need for the reintroduction of the other nonmetal category to raise any angst, given the considered way I am proposing to deal with it now (and the practice of PT.com and EB.com).

Having written all of this, if anybody is going to die in a ditch about the name "other nonmetal" it won’t matter much to me since I can still write about the properties of this bunch of nonmetals in the way I have described, although I will have to use more clumsy phrasing like, "The nonmetals other than the noble gases are characterised by…etc".

---

This is what I am talking about, as per PT.com and EB.com, and the way Wikipedia used to be:

Alkali metal

Alkaline earth metal

Lan­thanide

Actinide

Transition metal

Post-​transition metal

Metalloid

Other nonmetal

Noble gas

Unknown chemical properties

Scheme I

In the above option the relevant sections of the nonmetal article section would go something like:

Other nonmetal
There are eleven such nonmetals: hydrogen (H), carbon (C), nitrogen (N), phosphorus (P), oxygen (O), sulfur (S), selenium (Se), fluorine (F), chlorine (Cl), bromine (Br), and iodine (I). In periodic table terms they largely occupy a position between the weakly nonmetallic metalloids to the left and the noble gases to the right.

The other nonmetals have a diverse range of individual physical and chemical properties…

Noble gas
…

---

The other way is:

Metal						Metalloid	Nonmetal	Unknown chemical properties
Alkali metal	Alkaline earth metal	Lan­thanides	Actinide	Transition metal	Post-​transition metal		Noble gas

Scheme II

Updated 12 Oct to make clearer my personal preference that metal, metalloid, and nonmetal are super-categories; that metal spans six categories; that metalloid spans none; and that the nonmetal super-category has one category. Just as the seven metalloids are not further categorised below their super-category level, neither are the eleven nonmetals that are not noble gases. In classification science terms I suspect that if we can have a super-category that spans several categories, and another one that spans none, then a super-category with one category should be nothing unusual. Sandbh (talk) 05:07, 12 October 2017 (UTC)

In the above option the relevant sections of the nonmetal article section would go something like:

Nonmetal (other than noble gases)
There are eleven such nonmetals: which are hereafter, for convenience, referred to as other nonmetals ^{(strikeout added Sandbh (talk) 05:07, 12 October 2017 (UTC))} hydrogen (H), carbon (C), nitrogen (N), phosphorus (P), oxygen (O), sulfur (S), selenium (Se), fluorine (F), chlorine (Cl), bromine (Br), and iodine (I). In periodic table terms they largely occupy a position between the weakly nonmetallic metalloids to the left and the noble gases to the right.

The other ^{(Sandbh (talk) 05:07, 12 October 2017 (UTC))} nonmetals in question have a diverse range of individual physical and chemical properties…

Noble gas
…

Sandbh (talk) 05:45, 20 September 2017 (UTC)

Allow me to add another scheme:

Metal

Metalloid

Nonmetal

Unknown chemical properties

Alkali metal

Alkaline earth metal

Lanthanide

Actinide

Transition metal

Post-transition metal

Noble gas

Scheme IIa

I'd like to get rid of the white spacing between the two patches of nonmetal color. This is my attempt to show that the noble gasses form just a subset of the nonmetals but that there isn't a specific name for the NNNM. YBG (talk) 06:50, 20 September 2017 (UTC)

(further threaded discussion moved below to #Comments from YBG. YBG (talk) 06:39, 21 September 2017 (UTC)

Nonmetals: Discussion

Comments by Double sharp

I'm really sorry, but using "other nonmetals" without qualification, and without saying at least once what they are other too, still sounds really weird to me. It makes it sound like a term in itself. I know we've been through this with "transition metals", but the truth of the matter is that "transition metals" has become a standard term in chemistry with a sharply defined meaning (groups 3 to 11, and maybe 12), while this is not true for "other nonmetals".

On reading the response to your RfC above, I think one of my priorities in categorisation would be to not make up new terms by ourselves. I think we are all agreed that some nonmetals are more reactive than others, but I think we would also agree that we cannot make a blanket statement that P is less reactive than I; P is more likely to catch fire at standard conditions, after all. At the most we can use something that is indisputable and quantitative that nevertheless correlates reasonably and suggests the trend at work.

I think the greatest strength of the polyatomic/diatomic classification is that it is quantitative and, well, correct enough that it does not attract argument. No one can argue that, in their standard states, C, P, S, and Se are polyatomic, and H, N, O, F, Cl, Br, and I are diatomic. Reality is fuzzy and I would not be fussed if this one predictor of reactivity is not universally applicable, with a commonly encountered polyatomic allotrope of O, as well as the odd cases of H and N. There are many other factors at work, but it would be the height of folly to disregard them all because none of them explain everything by themselves.

Reality is always fuzzy, so we cannot use that directly as a categorisation. Every categorisation implies a certain straitjacketing of reality to fit the narrative, whether it be categorising chemical elements (is Bi really a metal?), musical styles (is Schubert really a classicist or a Romanticist?), or languages (what is a dialect, really?). But the power of categorisation is that it lets us suggest the more complex underlying reality, and provide us with a welcome beginning trail while we learn to navigate the terrain there – provided that we do not take the trail too seriously, and remember that it is only a guide. Double sharp (talk) 06:05, 20 September 2017 (UTC)

P.S. On reading through the archives I strongly suspect that "other nonmetals" as a category would end up being about as well-received as "other metals" was in the past: that is, not well at all. Double sharp (talk) 07:09, 20 September 2017 (UTC)

Plus that "other nonmetals" may be defined differently in other wikis, usually the nonmetals remaining after halogens are categorised too (as NG's are) (see de:Nichtmetalle). While this my look a wikipedia-issue only, it probably signifies an understanding in RL chemistry too. Note that this is about the category naming only, not its existence. -DePiep (talk) 15:36, 20 September 2017 (UTC)

Comments by DePiep

A strong step this is, Sandbh, after all that effort in an other direction.

• Procedural: See WP:RFCEND. I'd prefer not to have closing conclusions, since those could impede or prejudice future development. (For example, if a conclusion would be "not acceptable to devide the other nonmetals into subcategories" --I made one up--, we'd be blocked for any other improvement in this). Better would be to, e.g., withdraw the RfC, and allow using the comments, so rich in content, for next steps. And maybe wait one more week to gather some more? -DePiep (talk) 06:38, 20 September 2017 (UTC)
• In overview, I see separate angles of objection:

1. The new categories not being mainstream or even in stream (fringe science; OR even?),

2. The proposed names of the categories,

3. The actual categorisation per element (includes category definition and border issues),

4. The 'right' to categorise at all, being an encyclopedia not a journal.

I mention them here because they may recur, and need to be distinguished. Also, this list may be up for improvement & refinement. -DePiep (talk) 06:38, 20 September 2017 (UTC)

Comments from Parcly Taxel

We already had the conclusion for what to call the other nonmetals earlier: the chemically active nonmetals. Nevertheless, I'm so concentrated on life in university that I won't need to contribute anymore to this project – or even Wikipedia.

I can finally do the mathematics I always wanted to do. I'm looking to go to the Sorbonne or some other French university in 2019 or 2020 to play the game at its very best. So this, after six years, I hope will be a final farewell. Parcly Taxel 08:09, 20 September 2017 (UTC)

What a great view. Future and ambition! Enjoy and soak it all, is my wish for you. I still hope we will read more from you here. And thanks, F = FA for example. -DePiep (talk) 17:29, 23 September 2017 (UTC)

Comments from R8R

I think this is a step in the right direction, but not quite there yet.

First of all, I have carefully analyzed what you have written. The problem is that most readers won't even know there is something to analyze because most readers won't click the link and won't read the article nonmetal. Second of all, I would easily consider it a bad design if we had a colored metal category without a single element being colored as one. So I'd down vote the versions II and IIa. Version I is worth investigating into, though.

I see why you're thinking of the possible "other nonmetal" (regardless of the name) category as of an untercategory, if some German is allowed. I've been thinking something along these lines myself, so I quite understand this thinking. I have said I could give up my support on this category if there ever was a good break, and I've meant it; the problem is, there hasn't been one and I no longer believe there is one at all. (Though I remain open-minded on this one to new suggestions.) However, I don't find it necessary to underline so much that these elements have nothing in common so they don't have a defining characteristic when there clearly is one: they are reactive unlike the noble gases. Even nitrogen (the element; the periodic table is filled with elements, not substances they form at STP) is clearly reactive. This is a clear definition if you apply the common sense just like you do not to count all nonmetals as monoatomic because they are at some extreme conditions. We could have "reactive nonmetals" and keep on thinking that this isn't the perfect category but the best thing we've got. That'd be fine by me. If this name still isn't good enough, we also could go with "chemically active nonmetals"; that's, too, a fine name. How's that sound?

To summarize the previous paragraph, I believe a not-so-perfect category and a proper name is better than a not-so-perfect category and a poor name, and there are genuinely good options regarding the name for this category on the table.--R8R (talk) 18:07, 20 September 2017 (UTC)

Comments from YBG

Two comments

• In retrospect, it may have been better to use "corrosive nonmetals", as I think it may have removed some of the uncertainty as to whether N and P belonged in that category. But that may not have made any difference, and even if it had, it's water under the bridge now.
• When a category has a proper name, it is helpful to consistently use it in each and every situation - paragraphs, infoboxes, charts and diagrams, the whole lot. But when a category has no perfect name, it may be that different terms are suited in different situations. After mentioning the inertness of the noble gases, it would be perfectly natural to say something like, "On the other hand, the chemically reactive nonmetals ...." Other sentences might work best simply saying "the other nonmetals" or even "the non-noble nonmetals". By avoiding an absolutely rigid insistence on consistent nomenclature, we could choose to use the descriptive phrase best suited to each circumstance.

Just a couple of random thoughts. YBG (talk) 04:42, 21 September 2017 (UTC)

(Here follows a threaded discussion moved from above) YBG (talk) 06:39, 21 September 2017 (UTC)

Allow me to add another scheme:

Metal

Metalloid

Nonmetal

Unknown chemical properties

Alkali metal

Alkaline earth metal

Lanthanide

Actinide

Transition metal

Post-transition metal

Noble gas

Scheme IIa

I'd like to get rid of the white spacing between the two patches of nonmetal color. This is my attempt to show that the noble gasses form just a subset of the nonmetals but that there isn't a specific name for the NNNM. YBG (talk) 06:50, 20 September 2017 (UTC)

re YBG: Scheme IIa is an improvement, because each row now is a full & complete categorisation scheme by itself (just the zoom level changes: general or detailed). Scheme II misses the "other nonmetals" in the bottom row, making that row incomplete. re whitespace: so far we've not added a meaning to the border (in the scheme), let alone variant borders. I don't think the scheme itself (the graph) is the place to add this. Expect it to be described in article(s); see metalloids for example. -DePiep (talk) 15:47, 20 September 2017 (UTC)

re "so far we've not added a meaning to the border" I'm not proposing to add a meaning, I just think that removing the white space would subliminally emphasize the fact that  Nonmetal  in the upper row and the       in the lower row both use the same color. YBG (talk) 04:57, 21 September 2017 (UTC)

Now I see. Well, as theym are different categories (by definition, by element list), they should have different colors (unlike metalloids). But we'll get to this in the end, color is editorial only so not an issue now. (For clarity, you could use that new yellow or green one for the smaller box). -DePiep (talk) 05:37, 21 September 2017 (UTC)

(end of moved discussion, the remainder was created here)

I suppose I should have created both Scheme Ia and Scheme IIa as follows:

Schemes Ia & IIa: YBG's versions of Sandbh's Schemes I & II

Scheme Ia	Metal Metalloid     Nonmetal Unknown chemical properties Alkali metal Alkaline earth metal Lanthanide   Actinide   Transition metal Post-transition metal Other nonmetal Noble gas
Scheme IIa	Metal Metalloid     Nonmetal Unknown chemical properties Alkali metal Alkaline earth metal Lanthanide   Actinide   Transition metal Post-transition metal   Noble gas

First of all, when I looked at Sandbh's Scheme I, what I actually imagined in my head was Scheme Ia. But on reflection, the lack of the first row ay or may not have been intentional, so I have here created Scheme Ia. Now I understand the desire of DePiep to distinguish different (sub)categories by using different colors. But if we do that, there is virtually no difference between Scheme Ia and Scheme IIa.

The point of Scheme IIa is to show, by repeating the color, and by ^{using a narrower box} showing no name, that the 11 NNNM are somehow or other NOT a full-fledged category, that is to say, they lack their own defining properties and have no proper name. Personally, I don't like this sort of categorization, I want categories to be mutually exclusive and jointly exhaustive. But if what we want to say is that these 11 aren't a subcategory but merely the leftover elements after removing the NG from the NM, then Scheme IIa is precisely the way to show that. What I dislike about Scheme IIa is not its re-use of colors, but the presence of 11 elements that don't have their own 2nd level subcategory. I really don't like that. But if I want to illustrate that categorization, then Scheme IIa, complete with the re-use of the color, is IMHO, the best way to illustrate it. YBG (talk) 06:39, 21 September 2017 (UTC)

I have succeeded in removing the white inter-cell margin from Scheme IIa above. YBG (talk) 06:55, 21 September 2017 (UTC)

We should dissociate the questions of (1) whether a categorisation is a good idea and (2) whether a legend is showing it well, and while I am so far not convinced of (1), I am certainly convinced of (2) here. Double sharp (talk) 07:10, 21 September 2017 (UTC)

@Double sharp: You managed to communicate in a single sentence what took me two paragraphs. Bravo! YBG (talk) 07:23, 21 September 2017 (UTC)

@YBG: Thank you! Double sharp (talk) 07:25, 21 September 2017 (UTC)

I added an ^expansion to a previous comment, marking it with ^superscript text. YBG (talk) 07:42, 21 September 2017 (UTC)

And I have now managed to restore the white borders between differently-colored cells while retaining the joining of the two      -colored cells. YBG (talk) 07:57, 21 September 2017 (UTC)

And much as I dislike Scheme IIa, think for a minute about what you would expect to see in an article entitled "Chemistry of nonmetals" or "Electronegativity of nonmetals" or similar. I think you'd expect to find information about the 11 NNNM. While everyone agrees that the noble gases are nonmetals, I think that in the context of chemistry, you wouldn't expect to see information about noble gases unless you are explicitly told to expect it, as if an article was called "Electronegativity of the noble gases" or perhaps (gasp!) "Chemistry of the noble gases and other nonmetals". Or consider the sentence: "Nonmetals tend to form ionic bonds with metals covalent bonds with other nonmetals." I have no idea how NG bonding is analyzed, but it seems to me that no one would read this sentence and start thinking about noble gases. Well, no one except for nerds editing an encyclopedia, who therefore are always thinking about not just the specific things in focus but also all the rest of the WP:ELEM universe. Does any of this make sense to anyone? Or am I (once again) making a fool of myself by trying to make too much of my limited knowledge. Enlighten me, please. YBG (talk) 08:26, 21 September 2017 (UTC)

I might agree for He, Ne, and Ar, whose chemistry is rather vacuous. But I suspect that most chemists would think of Kr, Xe, and Rn as fairly normal elements which comport themselves chemically rather like their neighbours Br, I, and At one oxidation unit lower. After all, compounds like KrF₂ and XeO₃ are fairly clearly covalent, and are clearly analogous to [BrF₂]⁻ and [IO₃]⁻ respectively. (RnF₂ is I guess an exception, but even PCl₅ is on the covalent-ionic divide already.) After all, R. Bruce King's book on main-group chemistry covers groups 17 and 18 in the same chapter. ^_-☆ I don't think I would treat Kr, Xe, and Rn as not being nonmetals, and I don't think anyone would either: and the marginalisation of He, Ne, and Ar is only because they have no chemistry to talk about at standard conditions. Double sharp (talk) 09:03, 21 September 2017 (UTC)

P.S. Powell and Timms' The Chemistry of the Non-Metals includes the noble gases, the eleven NNNM's, and the metalloids. (And while I might quibble about whether the ontological approach is most appropriate here, I think it's unquestionably true that ontologically, metalloids are non-metals. I include the hyphen to differentiate "non-metal", which to me implies the ontological approach, from "nonmetal", which may have some independence in its definition from that of a metal.) Double sharp (talk) 09:07, 21 September 2017 (UTC)

#Scheme IIa is inacceptable, because you declare two different categories the same (by intentionally using the same color). The scheme has this to convey: row 1 = categories metal-metalloid-nonmetal, and row 2 = alkali metals-...-noble gases. Each row by themselves is mutually exclusive and jointly exhaustive (good wording!). The vertical connection is: "x is a subcategory of y". When a category is defined exactly the same above and below (metalloids), they can & should use the same name & color. However, not so for the Scheme IIa "nonmetals [row 1]" vs "some nonmetals [row 2]". With this, changing the border is trivial and has no meaning. And I repeat: this only needs to be solved once we have some agreement on those 11 nonmetals category (unless you really want to shake up the bigger scheme, which I did not read). -DePiep (talk) 09:46, 21 September 2017 (UTC)

It seems to me that the primary purpose of a legend is to be easily understood, not to conform to some hard-and-fast rules that usually correlate with easy understanding: that is similarly why abuses of notation exist in mathematics. So I do not see the problem in the colouring: it may be unusual, but I think it is clear to everyone what it means. (I may revise this position if someone can come up with a plausible alternate reading of the legend pictured.) Rather, I would critique the categorisation. But that is a different issue, as I have already stated above. Double sharp (talk) 09:56, 21 September 2017 (UTC)

It's not "unusual", it is dead wrong because it breaks the categorising principle. This way, two categories are defined both named "nonmetals" while one contains all nonmetals and the other one contains just eleven. Nonsense, to be rejected before causing headaches. "it is clear to everyone what it means": no, it has (actually: "they have") two different meanings so "it" can not be clear. We are not in need for such informal nudge nudge wink wink concepts. -DePiep (talk) 16:19, 21 September 2017 (UTC)

(Also, it is unclear which problem is actually 'solved' this way). -DePiep (talk) 16:19, 21 September 2017 (UTC)

I think you're expecting a sort of strictness in categorisation that is simply not present in the way the terms tend to get used in chemistry. Contrary to what the pretty colours everywhere tell us, element categorisation is a fairly fuzzy concept, and chemists simply don't expect them to be mutually exclusive or jointly exhaustive; they would simply mix and match whatever analogy or grouping is most germane to the situation at hand. It just so happens that some categories are more often used than others, and are thus more "standard" in the sense that people understand what they mean. But it is indeed, as you put it, very much an "informal nudge nudge wink wink concept" compared to the groups.

The idea here is simply that you have these 17 nonmetals, and while you can group some together as noble gases, the others don't really have any standard name for them. If it is that much of a problem to display this reality, simply because it doesn't provide neat little boxes, I would much rather avoid splitting the nonmetals at all, and simply let the little "18" at the top of the column take care of the noble gases. Double sharp (talk) 00:16, 22 September 2017 (UTC)

P.S. The WP categories are not even mutually exclusive anyway: since we consider La to be in group 3, the IUPAC definitions mean that La is both a lanthanide and a transition metal, and similarly Ac is both an actinide and a transition metal. Double sharp (talk) 00:19, 22 September 2017 (UTC)

Again, what problem is being solved? I get the strong impression that because some people have difficulty with naming a category, they want to abolish an RL existing category. (and P.S.: both otherstuffexists and border issues do not count). -DePiep (talk) 16:01, 22 September 2017 (UTC)

The problems lie in your sentence "RL existing category". First is the assumption that these categories exist in real life. They don't: they are just human constructs aimed at organising the messy reality before us. That is why every supposed category has its more or less representative members. The groups and periods have more of a real existence, because they simply ask one scientific question: "how many electrons are there in the valence subshells?" or "how many subshells are filled?". You can give a yes or no answer to those. Categorisation asks a different question: "how should I split the elements for my purposes?". Scientific inquiry can give you suggestions to the answer: it can tell you what commonalities are illuminated and which are obscured by each split, as well as the same for the differences. But at the end of the day the decision is yours based on what you think is more important to show, and science isn't going to tell you that. There's a good reason why group and period are words you learn in first-year chemistry, while category is not. If it were really that clear-cut, then perhaps we would have stopped the never-ending differences in the boundaries of the metalloids, which have ranged from including nothing to just about everything in the p-block.

The other problem is in the assumption that the set of elements {nonmetals} \ {noble gases} has a standard name. The fact that we can't seem to think of anything better than "non-noble nonmetals" seems to show otherwise, and indeed you will be hard-pressed to find anything else in the literature in case this group is meant. It is kind of like a supposed set {metals} \ {alkali metals}; if this set is ever needed for some freakish reason, there is certainly a way to describe it, but it is not at all a standard way to slice up the periodic table. (BTW, regarding "chemically active"; Rn is chemically active enough that there have been serious proposals to use chemical reactions to absorb it from air, just like is done with CO₂.) Double sharp (talk) 06:46, 23 September 2017 (UTC)

(outdent)

re. About our right to categorise, and use names for categories. I beg to differ on the statement "the assumption that these categories exist in real life. They don't". The categories too are based on a question, like groups and periods are, this time like: "which elements show non-metallic, inert behaviour" or so. The answer lies in nature, and can be found empirically, and then be published. Not my personal opinion. Sure border situation elements exist, but that does not undo the element clustering, i.e., some elements gathering closer to the core claim a category makes. The 118 elements are not randomly or continuously spread wrt such properties. Categories are not taught in first year chemistry? Does not say anything about their existence in RL. Sure, some are more important or strongly defined or used in practice, and some are fringe science (as the two RfC'ed categories are I understand). Altogether: categories exist in nature, can be researched & sourced, and so this encyclopedia has a right to describe them.

About completeness. This being the periodic table, it is worth covering the whole once when possible. That makes the categorising way way more meaningful, as it illustrates a trend in the periodic table. For this reason, border issues are to be neglected (well, declared less important), and scholars are supposed to get that. For this reason too, we can rightly add less-important categories to cover all, instead of allowing white 'undeclared' areas that actually are declarable (An example of ~non-trend information could be state of matter @STP, and other properties more randomly scattered in the PT; cristallisation?). Such is the history of the periodic table: Mendeleev too accepted irregularities to show the broad view.

Now since we do use the complete, trending categories principle, we are not free to leave that incidentally. That would undo the categorisation background, would leave the scheme less useful for what it tries to show, would break its periodic table relation: would make the scheme worthless. Especially creating one category with two definitions and two element lists (Scheme IIa) defeats all logic, and introduces ambiguity that is nigh impossible to explain/describe/de-confuse/un-soup. The Abuse of notation motive Double sharp mentioned above is useful when it would clarify stuff, but also says: ... the correct intuition (while being unlikely to introduce errors or cause confusion). This, while other options exist (have two distinct categories).

At last, about names of categories. Of course, when an established name exists we use it. However, when such a name is not available, we can rightly introduce a descriptive name. And again because of the trend reason I mentioned above, it is acceptable to use relative category names, such as "non-...", "post-", "elements that are not ...". An article or section can describe it, giving context. Also less-prominent classifications can be rightfully described in articles. E.g., pointing out the corrosive nonmetals as is done in Sandbh's nonmetal article proposal is perfectly acceptable (though we should not publish those broadly in our standard PT because fringe). For this, relativeness and descriptiveness, names like "other nonmetals" and "non-noble nonmetals" are OK, and also "the elements: ..." or "category that has no name for weird reasons"; all with grades of best-ness. Any such a name is better than no name. re "if this set is ever needed, ...": I don't agree with the 'it's not used/needed/taught' reasoning to accept/reject a category (in the RfC this was brought forward too). If it exists & sourced, we can use it. Some categories are more 'fringe' (less commonly referred to) than others, but when lacking anything better we can use it. Here too, completeness of the scheme trumps daily usage. -DePiep (talk) 09:20, 23 September 2017 (UTC)

re the RL existence of categories. Yes categories are based on the answers to questions just as groups and periods are. The human/editorial aspect comes in the selection of the questions to ask. Questions about shells and valence electrons are by universal consensus accepted as important questions. Selecting which questions to use for a categorizing scheme has yet to achieve anything like universal consensus, much less WP consensus.

re using names at two levels of a hierarchy. The English language does this all the time, and native speakers find it so easy to disambiguate that they hardly ever notice absent something external that brings it to the fore. For example, the word "man" was once universally used with several meanings, (a) any human being (b) any male human (c) an adult male human. And consider the word "European". If you were to overhear a discussion at a bar in New York complaining about "the European way of doing things", it would mean something quite different than if you heard the same complaint in a London pub. Scientists rightly try to avoid such ambiguity by looking to use words like "continental".

YBG (talk) 20:30, 23 September 2017 (UTC)

re [I'm disappointed] -DePiep (talk) 19:45, 24 September 2017 (UTC) [self-redacted, -DePiep (talk) 19:44, 28 September 2017 (UTC)]

Comments from Sandbh

At the moment the status quo of polyatomic/diatomic/monatomic noble gas is what we have. That is fine by me. I would now like to adjust the existing nonmetal article to bring out some more of the interesting properties of the polyatomic nonmetals and the diatomic nonmetals. For example, H is a bit of an odd element among the diatomics but then H is difficult to place generally. But the strongest hydrogen bonds are formed with the most electronegative elements i.e. N, O, F, and that seems another good enough reason to count H along with N, O, F, Cl, Br and iodine, noting as well that the properties of H are sometimes compared to group 17. Sandbh (talk) 02:42, 27 September 2017 (UTC)

I'm not sure current categorisation polyatomic/diatomic/monatomic noble gas would stand an RfC (could look a lot like current one). I'd say split non-metals into two: NG and NNNM. Meanwhile, article nonmetals could be as detailed as its sandbox now is (with a few tweaks in periodic table connection, reflecting the categories). -DePiep (talk) 20:43, 27 September 2017 (UTC)

We won't need an RfC since the current scheme stands, which is polyatomic/diatomic/noble gas. Sandbh (talk) 23:19, 27 September 2017 (UTC)

Sure we don't need one. But... anyone could start one, and then we can expect the same arguments & consequences. -DePiep (talk) 10:50, 29 September 2017 (UTC)

• What would it take to close the current RfC? Should we get an uninvolved editor to do it? It looks like no consensus to me, but ... YBG (talk) 00:20, 28 September 2017 (UTC)

@YBG: Hmm. I can close it. Consensus does not require agreement and many of the opposes are groundless as I now read them. We are not talking about introducing new category names as such, only descriptive phrases to distinguish between different kinds of nonmetal. Let me see how it looks. There sure are a lot of opposes. Sandbh (talk) 04:41, 28 September 2017 (UTC)

@Sandbh: If I were going to do it, I'd close it as 'no consensus' - which is pretty much the same thing as 'oppose'. YBG (talk) 05:43, 28 September 2017 (UTC) YBG (talk) 05:44, 28 September 2017 (UTC)

@YBG: Noted. Sandbh (talk) 05:45, 28 September 2017 (UTC)

In this case I would much prefer to leave the closure to an uninvolved editor. I was okay with you closing the one on group 12 because it really was unanimous, but I think the opposition has made some quite pertinent points – notably that putting descriptive phrases in this prominent a position effectively transmutes them into new category names. Double sharp (talk) 06:07, 28 September 2017 (UTC)

Formal closure (by anyone) could leave us with explicit conclusions that could hinder the issue development in the future (some road may be closed in general). An other option would be 'withdrawal' by Sandbh, (then we still can digest & use comments). And re YBG: I don't think 'opposed' is the same as 'no consensus' in this situation. See also WP:RFCEND. -DePiep (talk) 06:40, 28 September 2017 (UTC)

@DePiep: Thanks for the link. My comment re oppose=no-consensus was merely meaning to say that both results leave WP articles in their status quo ante. I was not considering the long term, which you helpfully considered. And I agree 100% that the best result would be for Sandbh to withdraw the RfC, i.e., to end it by removing the {{rfc}}. YBG (talk) 04:30, 30 September 2017 (UTC)

BTW, I'm preparing a sort of basical reply in the RfC, I could use one more day. -DePiep (talk) 06:42, 28 September 2017 (UTC)

• @Sandbh:. In this thread's OP you advocated to use something like "other nonmetals" (unfortunately is was about that name only, not about the correctness of that category, but alas). I thought that was to introduce a single category for the NNNMs. But now you state that the two poly-/di-atomic nonmetal categories are fine. Would you feel strong about one to the two options? (As said, describing all categorisations in the article nonmetal is fine, and is not limited by our main category set in any way). -DePiep (talk) 10:55, 29 September 2017 (UTC)

Response to DePiep
@DePiep: I haven’t replied so far as I’ve been stumped for an answer. I proceed with the greatest of trepidation in submitting the following thoughts.

The marvelous variety and infinite subtlety of the non-metallic elements, their compounds, structures and reactions, is not sufficiently acknowledged in the current teaching of chemistry.

JJ Zuckerman and FC Nachod
In Steudel's Chemistry of the non-metals (1977, preface)

In trying to understand the nonmetals I think there are seven perspectives to consider:

(1)	The general properties of nonmetals at standard conditions e.g. volatility, low elasticity, good insulators, they gain or share electrons when they react with other elements or compounds.
(2)	Their structures, nonmetals having a low number of nearest neighbours compared to metals.
(3)	Which of their properties are surpassed by some metals e.g. the ionisation energy of Hg exceeds that of S and I; the electronegativity of Au exceeds that of P; the electron afinity of Cd is less than than that of N.
(4)	Their anomalies e.g. H’s uniqueness; N’s low electron affinity and relative inertness, P4’s reactivity; Xe’s relatively low ionisation energy; first row v second row differences.
(5)	The chemistry of the nonmetals by group.
(6)	Patterns and trends among the nonmetals in ionisation energy, electron affinity, electronegativity and oxidising power.
(7)	Cross-cutting relationships.

I think if you can keep all this in your head than you can follow why the nonmetals are as diverse as they are. The current nonmetal article only largely does (1) and (2). The rewrite adds some of (4) and (5); a little of (6); and (7). A further rewrite would add or expand (3); (4); (5); and (6).

I tend to think a further rewrite might best be done by having only two formal categories of nonmetal: the top-shelf nonmetal category for H, C, N, P, O, S, Se, F, Cl, Br and I; and a single noble gas subcategory (noting the metalloids are similarly in a top-shelf category and have no subcategory).

The nonmetal article might go partly like this:

Nonmetals are H, C, N, P, O, S, Se in group 1 or groups 13–16; F, Cl, Br, and I in group 17; and the noble gases He, Ne, Ar, Kr, Xe and Rn in group 18. For convenience within this article, nonmetals other than the noble gases are hereafter referred to using the descriptive phrase "chemically active nonmetals"; and the four group 17 elements are referred to as "halogen nonmetals". Of these terms only "noble gases" and "halogen" are IUPAC-approved.

The chemically active nonmetals have a diverse range of individual physical and chemical properties. In periodic table terms they largely occupy a position between the weakly nonmetallic metalloids to the left and the noble gases to the right.

Physically, four are solids, one is a liquid (bromine), and six are gases. Of the solids, carbon, selenium, and iodine are metallic-looking, whereas sulfur has a pale-yellow appearance. Ordinary white phosphorus has a yellowish-white appearance but the black allotrope, which is the most stable form of phosphorus, has a metallic-looking appearance. Bromine is reddish-brown in colour. Of the gases, fluorine and chlorine are coloured pale yellow, and yellowish green. Electrically, most are insulators whereas carbon is a semimetal and black phosphorus, selenium and iodine are semiconductors.

Chemically, they tend to have higher ionisation energies, electron affinities, and electronegativity values, and be relatively strong oxidising agents, in comparison to metals. Collectively, the highest values of these properties are found among oxygen and the halogen nonmetals. Manifestations of this status include oxygen's major association with the ubiquitous processes of corrosion and combustion, and the intrinsically corrosive nature of the halogen nonmetals. All five of these nonmetals exhibit a tendency to form predominately ionic compounds with metals whereas the remaining nonmetals tend to form predominately covalent compounds with metals.

Characteristic and other properties of metalloids, chemically active nonmetals, and noble gases are summarised in the following table. Metalloids have been included in light of their generally nonmetallic chemistry. Physical properties are listed in loose order of ease of determination; chemical properties run from general to specific, and then to descriptive. While the table shows the main points of difference it is somewhat arbitrary since exceptions and boundary overlaps can be found within each category, set, or subcategory. Important instances of such are so noted.

In writing this it occurs to me that such an approach might work just as well for the di/polyatomic/noble gases. So, after all that, I still don’t know which one will work best. At least you know I haven’t stopped thinking about this/working on it.

I presume project members would be happy with either outcome, depending on how the article in question looked. Whatever the outcome my intention is to have a better, more lucid nonmetal article. It may be that I'll have to do both rewrites.

Somewhere, if we do not do so already, we perhaps need to say that:

(1)	our categorisation scheme, and its subcategories, is not definitive;
(2)	for convenience and economy of description we… (a) use IUPAC-approved collective names for the alkali metals, alkaline earth metals, and noble gases; (b) do not use the IUPAC-approved collective names lanthanoids, actinoids, rare earth metals, pnictogens, and chalcogens; (c) refer to the leftover elements as either post-transition metals, or metalloids, or "nonmetals" for nonmetals not categorised as noble gases i.e. H, C, N, P, O, S, Se and the halogen nonmetals (akin to the LANL periodic table);
(3)	there is a spectrum of properties within each category or subcategory;
(4)	it is not hard to find overlaps at the boundaries (see here), as is the case with most classification schemes.

And perhaps these caveats need to be flagged some more in the periodic table article.

I'm not sure if I'm completely happy yet with this post but I feel the need for some feedback, so "Save changes" here I come. Sandbh (talk) 03:56, 7 October 2017 (UTC)

• This is not my analysis of the RfC. Note that I already quoted & parsed the IUPAC section IR 3.5, with two notable conclusions:

1. IUPAC only lists categories with definite list of elements. Therefor we see no metalloids, metals, nonmetals (under any name), because the metalloids borders are not settled (a top level category btw, and logically spreading this issue to neighbouring categories and into subcategories like PTM, Other Nonmetals.

2. IUPAC does name the sets, but does not describe the sets. There is no description of the "like"-ness of these elements (there is no: in want sense are they "like"?).

Exception to both 1 and 2: transition metals wrt group 12 and d-block.

Now since IUPAC does not recommend 'metals', does that mean we cannot use that? No, we can. Most non-recommended (fully omitted) categories are established concepts, border element issues not denying the concept. More so in the top-level (3 categories, none is recommended). So my conclusion is: we can add a category like 'nonmetals', especially to use and complete the category set.

An other conclusion from the RfC comments, as I read it, is that the new proposed names are WP:FRINGE (that is not: WP:OR!) and therefor not acceptable. It is no big step to claim that poly-/di-atomic names are too. These subdivisions surely can be described in the nonmetal article (as your sandbox does; also subdivisions by other criteria), but can not be our generally published category.

However, the 11-element category is not fringe, and can be given a descriptive name for lack of any established name. A naming issue should not prohibit us of pointing to this category (please keep naming a category separate from category criteria; unlike (1) and (2). A source of trouble). -DePiep (talk) 08:15, 7 October 2017 (UTC)

My position, after the RfC: subcategories are WP:FRINGE (RfC says), we have a due right to categorise, IUPAC Recommendations are only valid for what they do say, the major categories are undisputably correct & acceptable at wiki (metal-metalloid-nonmetal), for completeness (covering the PT to show PT trends) additional categories are needed, any naming issue can nnot be a reason to not categorise. Practically: one category for the 11 NNNMs (Drop the current two per FRINGE), best named "active nonmetals", go detail in the nonmetal article. -DePiep (talk) 09:58, 7 October 2017 (UTC)

Here is what the comparative table would look like, in part:

Property	Metalloid	Nonmetal (chemically active)	Noble gas
Appearance	metallic	metallic, coloured, or translucent	translucent
Atomic structure	close-packed* or polyatomic	polyatomic or diatomic	monatomic
Bulk coordination number	12*, 6, 4, 3, or 2	3, 2, or 1	0
Electrical conductivity	moderate	poor to moderate	poor
Electronic structure	metallic* to semiconductor	semimetallic, semiconductor, or insulator	insulator
Ionization energy	low	moderate to high	high to very high
Electron affinity	low to high	moderate to high (exception: N is negative)	negative
Electronegativity	moderate	moderate to high	moderate to very high
Oxidising power	low (exception: At is moderate)	low to high	n/a
Compounds with metals	tend to form alloys or inter-metallic compounds	mainly covalent: H†, C, N, P, S, Se mainly ionic: O, F, Cl, Br, I	none form simple compounds

*Bulk astatine has been predicted to have a metallic face-centred cubic structure
† Hydrogen can also form alloy-like hydrides

It looks much better than what I had imagined. You can see the transition in metallic character going across the three columns. I can see a lot of potential for elaborating, in the article, the trends and patterns occurring in the central column. I'm happy and looking forward to finishing the table and adjusting the article accordingly and our categorisation scheme. Sandbh (talk) 07:48, 8 October 2017 (UTC)

Merge proposal for lithium

See this discussionto merge Lithium as an investment into lithium. It started last June. -DePiep (talk) 09:25, 5 October 2017 (UTC)

Standard atomic weight

I've listed the standard atomic weights central: {{Infobox element/symbol-to-saw}}. Also for most stable isotope (when no s.a.w. exists): {{Infobox element/symbol-to-most-stable-isotope}}. This helps control correct number & formatting throughout.

By now, we should be familiar (actually, I'm happy that I am, at last ;-) ) with the variant values that IUPAC (CIAAW) publishes for each element. That is, next to the formal s.a.w. (often a long number, and possibly an interval), the element may also formally have an abridged and a conventional value. The resulting short number value I started naming "formal short" here.

Please check {{Periodic table (18 columns, large cells)}}, as it now mentions two values. OK?

Over at Wikidata, things are a mess (see this comparision). WD 'must' have a mass unit, so they've added "u" (by recalculation); they've used PubChem as a source which has way different numbers, it is a mixup of long and short numbers. (One wonders what molecular weights are worth, when calculated by PubChem). Anyway, I'll start a talk over there. -DePiep (talk) 13:23, 8 October 2017 (UTC)

Looks good – except that I think we should define that values encased in square brackets are the mass number of the most stable isotope, not the nonexistent standard atomic weight. Double sharp (talk) 13:27, 8 October 2017 (UTC)

Yes. On my todo-list. See also {{Periodic table (standard atomic weight)}}. -DePiep (talk) 13:41, 8 October 2017 (UTC)

Numbers & values are clarified here. For starters, it's a 3×3 table. (Then add m.s.i. ...). -DePiep (talk) 20:41, 8 October 2017 (UTC)