Talk:Post-transition metal

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Moving poor metals here[edit]

I think that the labeling poor metals is at least confusing. I am also pretty sure that post-transition metals is the term used allover academia. Therefore I think we should switch all the legends also away from poor metal nomenclature. Nergaal (talk) 11:11, 3 August 2008 (UTC)

I don't know about moving the content of Poor metals here but I do agree that we should deprecate the use of the term from our infoboxes and lists. 'Post-transition metal' seems to be a good replacement but let's wait for others to comment before anything is done though. --mav (talk) 17:19, 3 August 2008 (UTC)
Support merge. The term poor metal can refer to different groups of metals that, for the most part, overlap the same group of metals in this article. Even this article points out that there are differing definitions of "post-transitional metals", so I don't see why poor metals couldn't be worked in. It's also a subtle way of depreciating the term "poor metal". Wizard191 (talk) 13:38, 4 August 2008 (UTC)
Plenty of notice has been given. I consider the issue closed in favor of a merge and think that anybody can go ahead and do it. --mav (talk) 02:21, 23 September 2008 (UTC)
I am 3 years late, but I am wondering how one can call aluminium a post-transition metal when there are no transition metals before aluminium. Or have I missed something? Double sharp (talk) 06:22, 29 December 2011 (UTC)
Count me in too as being confused about why we call aluminum a post transition metal. I'm also somewhat confused about why the term 'poor metal' was deprecated. What we call the post transion metals are better called poor metals, which would include aluminum. The post transition metals then become a subset of the poor metals. Sandbh (talk) 12:44, 18 June 2012 (UTC)


The first paragraph of section one is copied word-for-word from Jhalkompwdr (talk) 13:16, 23 August 2009 (UTC)

Hrm, first, the first sentence is different. After a small bit of research it appears the second sentence is completely legit. The oldest copy of your weblink is from January 2007 (here), so the last edit before January 2007 of the Wikipedia article has the sentence (here). That means the webpage copied it from Wikipedia. The third sentence looks like it could have been copied from the webpage, because it was changed in February 2007 (here). So, if perhaps the last sentence ought to be reworded. Wizard191 (talk) 22:45, 23 August 2009 (UTC)

Zinc, Cadmium, and mercury are transition metals[edit]

I think you should remove Zn, Cd, and Hg off of the side, unless... there is a reason to leaving it. —Preceding unsigned comment added by Wd930 (talkcontribs) 06:27, 4 December 2010 (UTC)

Poor and post transition the same, so[edit]

Since poor and post transition metals are the same set now, we could get rid of the second graph right? -DePiep (talk) 17:45, 23 October 2012 (UTC)

Reason for naming? -poor metals[edit]

Anyone know Why they are called Poor metals and the history behind it? --B. Srinivasa Sasidhar 01:02, 27 November 2012 (UTC) — Preceding unsigned comment added by Bssasidhar (talkcontribs)

Article move[edit]

On 17 August 2013 I moved Post-transition metal to Poor metal, as part of a technical move request. Due to WP:Parallel histories the move was not simple. The old content of Poor metal has been preserved in Talk:Poor metal/Old article copy and the old talk page is at Talk:Poor metal/Poor metal old talk page. A couple of paragraphs of content were taken from the old article to the new one by cut-and-paste in 2008 and these old copies should be kept around to maintain attribution. The {{Copied}} template is sometimes used to flag these cases of copying within Wikipedia. The details of the cut-and-paste move can be seen at [1] and [2]. EdJohnston (talk) 20:08, 17 August 2013 (UTC)

The move was part of "option 10" changes (diatomic and polyatomic nonmetals) WT:ELEM#Implementing_option_10. -DePiep (talk) 10:44, 18 August 2013 (UTC)

Merge- was it an improvement?[edit]

Personally I think not. Post transition was a well defined group of metals (unless of course you get confused by the idea of post being after!) The lede is a brave but unreferenced and probably unreferencable attempt to classify these metals by their properties. Aluminium stands out as being further from the lede definition than the rest. For example it has a close packed structure and good electrical conductivity, but the unusually high interatomic distance does not indicate covalency. According to Chemistry by Holman and Stone aluminium is called a poor metal because its oxide is amphoteric. This isn't a good criterion either - the wikipedia article on amphoteric oxides says "Some other elements which form amphoteric oxides are chromium, gallium, copper, antimony, bismuth, indium, silicon, titanium, vanadium, iron, cobalt, germanium, zirconium, silver, tin, and gold" and some of the metals in the list aren't usually considered to be poor metals. I can see why IUPAC deprecate this grouping. Axiosaurus (talk) 16:41, 26 August 2013 (UTC)

As a sidenote: wikitechnically, it was not a merge. Before, poor metal redirected to the content page post-transition metal. Today, it is the other way around. A redirect has or had its own section in the content page. This does not resolve the point Axiosaurus makes. As I understand it, the two are defined differently (e.g. wrt Aluminium) on this one page. In the periodic tables we have, today we only use the category "poor metal". That does not declare them the same; it's just you won't find the word "post-transition" in the PTs. -DePiep (talk) 18:06, 26 August 2013 (UTC)
The whole article was suffering from underdevelopment and neglect. I expect the lede will be referenceable. Aluminium is pretty poor although perhaps, as you noted, not the poorest of the poor metals. (But this happens in the other subcategories too, each showing a spread of applicable properties, resulting in both more typical members and outliers). 1. Yes, Al does show evidence of directional bonding. 2. When pure it is very soft, so much so that people who handle it are surprised to learn that it is aluminium. 3. It has a low melting point and a high thermal conductivity which makes it unsuitable for use in e.g. military ships—should a ship burn, the low melting point results in structural collapse; the high thermal conductivity helps spread the fire. 3a. 'Fire: The strength of aluminium is halved from its ambient value at a temperature of 200° C, and for many of the alloys is minimal at 300° C.' (Lyons A 2007, Materials for architects and builders, 3rd ed., Elsevier, Oxford, p. 170) 4. For other nonmetallic properties associated with its poor metal status, plus citations, see its bio in the metalloid article, noting also that Al has the highest appearance frequency in the list of metalloid lists, after the six recognised metalloids, and Po, and At. Sandbh (talk) 21:25, 26 August 2013 (UTC)
Updated with the addition, for reference purposes, of 3a. Sandbh (talk) 20:22, 27 August 2013 (UTC)
Just a point on the directional bonding. The evidence seems to be based on behaviour under shear. I am just a litle sceptical about the applicability to the unstressed crystal which is regular. Your points on aluminium structural issues are well made, however other structurally weak metals (group 1 - yes I know buildings would spontaneously combust when it rained!) do exist which are not classified as poor metals. Anyway I shall leave you to it. Axiosaurus (talk) 08:58, 5 September 2013 (UTC)
I can't access my references so will have to take on notice some aspects of your observation re directional bonding in Al. From the metalloid article I can see (however) that Boyer et al. (2004) say that 'Aluminium presents a greater challenge to empirical potential description because of the directional nature of its interatomic bonding' and, a little later, 'Aluminium has been shown to exhibit anisotropic electron density, which is closely associated with directional bonding.' I can remember Russell & Lee (2005) (see metalloid article for ref details) say that on the metal side of the periodic table, the closer you get to the metal-nonmetal dividing line the more often you will see evidence of directional bonding. And the literature on Al is consistent with that. Yes, the unstressed crystal is regular but the electron density isn't which leads to the peculiar shear behaviour in Al. Same thing happens in polonium, as I recall from Russell & Lee (2005): regular crystalline structure but showing anisotropic electron distribution.
As I further recall, there was some scepticism about the alkali metals when they were first discovered given they floated on water(!) and were soft. Because of these properties it was initially proposed to call them metalloids. Chemically, however, they were super-metals so that, in the event, they were admitted to the true metal club. Pure aluminium is a structurally weak metal. Its extra burden is that chemically it is also a weak metal, given its amphoterism, covalent bonding tendencies, and anionic aluminate formation—unlike any of the alkali and alkaline earth metals (except for Be and, to a lesser extent, Li). The combination of the two weaknesses, physical and chemical, and the proximity of Al to the metal-nometal dividing line, explain why it is sometimes classified as a metalloid, which I think is a step too far given its ductility and electrical conductivity, but poor metal—that's reasonable, noting there is a spread of properties amongst the poor metals and some are more or less poor than others.
Next week, all going well, i'll update the poor metal article along theses lines. Sandbh (talk) 20:05, 5 September 2013 (UTC)
Have you seen this paper? The Bonding Electron Density in Aluminum, Nakashima et al, 2011, doi:10.1126/science.1198543 - a bit more recent than the other ones- confirms the idea of a subtle anisotropy of electron density.Axiosaurus (talk) 15:31, 6 September 2013 (UTC)
Yes, thank you. I had a look at it. Interesting paper. I rechecked Russell AM & Lee KL 2005, Structure-property relations in nonferrous metals, John Wiley & Sons, Hoboken NJ, to see what they said, which was: "Al's partially [italics added] directional bonding gives it a high stacking-fault energy..." (p. 359). I presume they describe it as 'partially' directional given there is nothing directional about Al's close packed FCC structure, and that directional bonding only occurs at the nanoscale level (which, even so, has a mechanical consequence). Sandbh (talk) 00:34, 9 September 2013 (UTC)

p-block metals as synonym?[edit]

Does the term p-block metals have significant usage as a synonym for poor metals? If so, we could mention this synonym in the article. Dirac66 (talk) 02:31, 29 September 2013 (UTC)

Actually, there is an expanded proposal to include group 12 (d-block) into the poor metals. See Wikipedia_talk:WikiProject_Elements#Make_the_group_12_elements_poor_metals.3F. So the synonym is in doubt. Then there is also the "post-transition metal" group to keep in mind. -DePiep (talk) 02:46, 29 September 2013 (UTC)
OK, near-synonym then. I think that whatever is decided for poor metal, the relation between the three terms (poor metal, post-transition metal, p-block metal) should be explained. Now the relation between poor metal and post-TM is explained although they are not exact synonyms, and this is good since it will reduce reader confusion, but the third term p-block metal is ignored at the moment.Dirac66 (talk) 02:55, 29 September 2013 (UTC)
Hello Dirac66. I believe the relationship between p-block metals, post-transition metals and poor metals has been covered in the proposed rewrite of the poor metals article. If not, please let me know, before the 'p' key on my poor keyboard pops out from being pressed so many times. Sandbh (talk) 05:53, 29 September 2013 (UTC)
Yes, this rewrite is a much improved version of the article which does include my point. Thank you. Dirac66 (talk) 14:24, 29 September 2013 (UTC)

Why the name change from poor metal to other metal?[edit]

I updated the content of this article today. It used to comprise a redirect to poor metal. That redirect is gone and replaced with new content about the other metals. The content that was previously in the poor metal article been replaced by a redirect to this article.

Basic reason for doing so is that there is no widely recognised label for the second string metals between the transition metals and the metalloids. Wikipedia should reflect this, with individual writers and teachers being free to use more specific names of their choice, multiple examples of which are given in the article, as is the rationale for the descriptive phrase 'other metal'. See also here. Sandbh (talk) 11:40, 13 March 2014 (UTC)

Other is an undefined word here.[edit]

My dictionary defines the word other as meaning Not the same as one or more of some already mentioned or implied .... Here the word is used as the first word of an article title, so nothing has been already mentioned or implied, and the word is meaningless in this context. Wikipedia does not have articles entitled Other molecules, Other reactions, Other countries, Other presidents etc. etc.

If I understand correctly, this name was chosen because it was felt that none of the other synonyms considered is entirely satisfactory. My solution would be to choose the least unsatisfactory synonym and to mention its shortcomings. My own choice would be P-block metals, which also means Groups 13-16 of the periodic table. Dirac66 (talk) 20:14, 14 March 2014 (UTC)

Hi @Dirac66: Sorry I missed your post. Nergaal is talking on this topic, here. He has already changed the article from other metals to post-transitional metals without prior discussion. I think my response there covers off on your quite interesting suggestion. Happy to chat right here or at WikiProject Elements. Sandbh (talk) 12:32, 3 May 2014 (UTC)

Note that Sandbh is rewriting this article in their sandbox as post-transition metals. Double sharp (talk) 15:10, 8 July 2014 (UTC)

Some problems with article[edit]

  • Specifics: Inclusion of group 11 is based on Demings 1940 text book. No modern reference is given. The statement "Chemically, the group 11 metals behave like main-group metals in their +1 valence states" is unreferenced and simply wrong. The statement about silver "The chemistry of silver is dominated by its +1 valence state in which it behaves like the main group metals potassium or thallium." is attributed to Rayner Canham but I can't see it in the 5th edition. If they said it then it is at best an oversimplification.
I'll add some modern references to group 11 as post-transition metals. I've copy edited mention of the group 11 metals behaving like main group metals, and added a citation. My attribution to Rayner-Canham was laziness; I have a much better reference but need to (and will) check its publication status with Rayner-Canham. Sandbh (talk) 05:27, 2 August 2014 (UTC)
The more recent work by Rayner-Canham is not quite in press so I've added two other citations noting the similarities in physical and chemical properties of Tl(I) and Ag (I) compounds. Sandbh (talk) 11:28, 8 August 2014 (UTC)
  • General points:
The article is massively over-referenced.
This will get worse before it gets better. Sandbh (talk) 08:51, 14 August 2014 (UTC)
Some of the references seem odd e.g Sorensens, Metal poisoning in fish is the reference for the statement "There is an abrupt and significant reduction in metallic character from group 11 to group 12", surely there is a better known and more accessible inorganic chemistry text that could have been found. (But maybe not as other writers may not have this POV)
Good descriptive chemistry sources for the elements are hard to come by. I've clarified that the reduction in question was referring to physical properties. Sandbh (talk) 09:32, 2 August 2014 (UTC)
The article is missing some key points e.g. chemistry of Au is heavily influenced by relativistic effects, d-block contraction isn't mentioned at all.
Relativistic effects are mentioned in the Rationale section; d-block contraction is now included in the same section. Sandbh (talk) 07:21, 12 October 2014 (UTC)

Axiosaurus (talk) 11:37, 30 July 2014 (UTC)

Elements Silicon and Sulphur are swapped in the periodic table excerpt[edit]

Can the author of the periodic table excerpt or the maintainer of the article correct the position of Silicon and Sulphur? Silicon has the atomic number 14, situated in the group of semiconductors between Carbon and Silicon. Sulphur has the atomic number 16, situated in the group of chalcogens between Oxygen and Selenium. It should also be verified if similar pictures in other articles contain the same blunder. — Preceding unsigned comment added by Pia novice (talkcontribs) 16:09, 30 July 2014 (UTC)

Great point, thanks. Author Sandbh will surely correct it asap into 14S sulfur and 16Si silicon. -DePiep (talk) 19:00, 30 July 2014 (UTC)
Aside from correcting the picture (or even "instead of"), I would suggest asking WP:Graphic Lab to vectorize the image (that is, to re-draw the image as a .svg file, which can be done for a table like this and is generally considered good for such pictures).--R8R (talk) 21:13, 30 July 2014 (UTC)
So Nergaal agrees, then? Or are you speaking for yourself/by yourself? -DePiep (talk) 21:37, 30 July 2014 (UTC)
I don't think this comment is necessary. Double sharp (talk) 13:12, 13 August 2014 (UTC)
It may be not necessary, but clarifying it is. It separates an edit request from a command to edit. And also from the afterward, backward, backhanded editwar. -DePiep (talk) 21:47, 13 August 2014 (UTC)

I fixed 14Si and 16S. Double sharp (talk) 13:12, 13 August 2014 (UTC)

Excellent! Sandbh (talk) 13:24, 13 August 2014 (UTC)
Thanks. :-) Double sharp (talk) 18:23, 14 August 2014 (UTC)


Forgive my unencyclopedic edit summary here. We cannot compare temperatures like this unless they are absolute temperatures. --John (talk) 11:27, 27 September 2015 (UTC)

Hi John. Steel often melts at 1370 C = 1643.15 K. Al melts at 933.5K = 56.8% of 1643.15. Does this not support saying the mp of Al is just over half that of steel? Sandbh (talk) 11:46, 28 September 2015 (UTC)
Phew, so it wasn't as bad as I thought. This would only be of use if we were in the business of heating metals up from absolute zero until they melted. For most purposes, we are starting off around 298K. I think either give the temperatures or say "much higheJust over half the temperature doesn't seem to add much to me. --John (talk) 20:56, 28 September 2015 (UTC)
It seems to me that using multiplicative terminology like 'twice' or 'half' with temperature scales is inherently misleading to the reader, even in the one case where it would make sense - the thermodynamic behavior of gasses. For melting points, it makes absolutely no sense at all. I think it would be helpful to have a WP:MOS policy forbidding the use of multiplicative terminology with temperature scales. YBG (talk) 07:41, 14 February 2016 (UTC)

Lead hardness[edit]

I added the observation that anybody melting pure lead have made "(but hardens close to melting)". Is there anybody who know the reason?Seniorsag (talk) 14:21, 13 February 2016 (UTC)

According to this article, a proposed mechanism is that temperature produces a "ductility trough" and a ductile to brittle transition behaviour in the solid metal. If so, this phenomenon may be observable across all of the post-transition metals, given their relatively low melting points. Nice pick up. Sandbh (talk) 23:26, 13 February 2016 (UTC)