Talk:Post-transition metal

Latest comment: 1 year ago by Sandbh in topic Updated image in lede

Moving poor metals here

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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)Reply

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)Reply
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)Reply
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)Reply
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)Reply
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)Reply

Plaigarism?

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The first paragraph of section one is copied word-for-word from http://www.chemistry.patent-invent.com/chemistry/poor_metals.html Jhalkompwdr (talk) 13:16, 23 August 2009 (UTC)Reply

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)Reply

Zinc, Cadmium, and mercury are transition metals

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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)Reply

Poor and post transition the same, so

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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)Reply

Reason for naming? -poor metals

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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

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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)Reply

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)Reply

Merge- was it an improvement?

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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)Reply

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)Reply
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)Reply
Updated with the addition, for reference purposes, of 3a. Sandbh (talk) 20:22, 27 August 2013 (UTC) Reply
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)Reply
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)Reply
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)Reply
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)Reply

p-block metals as synonym?

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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)Reply

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)Reply
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)Reply
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)Reply
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)Reply

Why the name change from poor metal to other metal?

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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)Reply

Other is an undefined word here.

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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)Reply

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)Reply

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

Some problems with article

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  • 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)Reply
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)Reply
  • General points:
The article is massively over-referenced.
This will get worse before it gets better. Sandbh (talk) 08:51, 14 August 2014 (UTC)Reply
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)Reply
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)Reply

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

Elements Silicon and Sulphur are swapped in the periodic table excerpt

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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)Reply

Great point, thanks. Author Sandbh will surely correct it asap into 14S sulfur and 16Si silicon. -DePiep (talk) 19:00, 30 July 2014 (UTC)Reply
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)Reply
So Nergaal agrees, then? Or are you speaking for yourself/by yourself? -DePiep (talk) 21:37, 30 July 2014 (UTC)Reply
I don't think this comment is necessary. Double sharp (talk) 13:12, 13 August 2014 (UTC)Reply
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)Reply

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

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

Temperatures

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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)Reply

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)Reply
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)Reply
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)Reply

Lead hardness

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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)Reply

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)Reply

RfC: Colour group 12 as post-transition metals

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I am seeking comments on a proposal to color code the group 12 elements as post-transition metals in the Wikipedia periodic table, rather than transition metals as they are currently color coded.

The RfC can be found here. Sandbh (talk) 23:14, 9 August 2017 (UTC)Reply

Blurbs on the transactinides

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I have added these; references are to follow. Many of them are listed on WT:ELEM#Meitnerium through oganesson and in the element articles themselves. Double sharp (talk) 04:33, 22 April 2018 (UTC)Reply

Move discussion in progress

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There is a move discussion in progress on Talk:Alkali metal which affects this page. Please participate on that page and not in this talk page section. Thank you. —RMCD bot 06:15, 28 February 2019 (UTC)Reply

Further additions

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Strictly speaking, boron and silicon should be added as they are often treated as "metals" in organometallic chemistry. Double sharp (talk) 13:00, 16 May 2020 (UTC)Reply

Requested move 7 May 2023

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The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this discussion.

The result of the move request was: moved. (closed by non-admin page mover)MaterialWorks 00:49, 15 May 2023 (UTC)Reply


Metals close to the border between metals and nonmetalsPost-transition metal – This title is a description of what post-transition metals are, but not what it is. Interstellarity (talk) 23:17, 7 May 2023 (UTC)Reply

Provisional support.
The lede image makes things more complicated than they need to be.
The metals between the transition metals and the metalloids go by quite a few different names none of which are widely accepted. The most common technical one of these is “post-transition metals.” This is also a good descriptive name.
Most commonly the PTM are the metals in Groups 13 to 15.
Zinc, cadmium, and mercury are sometimes not counted as TM in which case they would be counted as PTM. They merit a 50:50 colouring.
Aluminium is occasionally not counted as a PTM given its absence of d electrons. Colour it as a PTM but add a footnote. Ditto Po which is sometimes counted as a metalloid but does not number among the elements most commonly recognised as metalloids.
Astatine is widely regarded as either a nonmetal or less often as a metalloid but has been predicted to be a metal. Colour it a halogen but add a footnote.
There a few other elements counted as PTM in isolated cases and that is all that needs to be said in the article. Colour these as their normal types. Sandbh (talk) 12:29, 8 May 2023 (UTC)Reply
  • Oppose. As the article shows, the two things are not necessarily the same, and there is not a standard name in the literature for this somewhat vaguely defined set of elements. Consequently a descriptive phrase seems to be the only possible neutral title. Double sharp (talk) 00:29, 10 May 2023 (UTC) Support. Data presented by Sandbh is convincing that "post-transition metal" is the most common term for this inherently fuzzy set. Double sharp (talk) 17:55, 14 May 2023 (UTC)Reply

Discussion

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@Double sharp: could you please consider withdrawing your oppose in light of the following information?

"Post-transition metal" would seem like a good descriptive phrase and more convenient than “Metals close to the border between metals and nonmetals”, given the transition metals occupy groups 3 to 12 or sometimes to 11. It is the most common technical term and could sustain an article on that basis, at the same time noting the range of alternative names for the leftover metals and their sometimes or occasionally varying membership.

Nyholm, a leading figure in inorganic chemistry in the 1950s and 1960s, referred to the properties and structure of transition metal to post transition metal covalent bonds (1966).

Kepert & Vrieze, in chapter 47 of the classic Comprehensive Inorganic Chemistry (1973, p. 313), refer to bonds between transition metal and post-transition metal atoms.

Greenwood and Earnshaw (1998, p. 548) mention that "bismuth is a typical B sub-group (post-transition-element) metal like tin and lead."

Driess and Nöth, in their book Molecular Clusters of the Main Group Elements (2008, p. 19) write that, "Extensive definitive structural information on anionic post-transition metal clusters was obtained by Corbett only in the 1970s."

FA Cotton in Progress in Inorganic Chemistry, vol. 8 (2009, p. 115) refers to eight-coordinate post-transition metal radii.

Kalantar-Zadeh et al. (2021) refer to the use of low-melting-temperature (LMT) metals and alloys based on post-transition metals.

A search of Google Scholar for post transition metal/s yielded about 9,000 hits, of which 6,000 date from 2013.

Until today I wasn’t aware of how extensively “post transition metal/s” was/is used.

I suggest that if the term was used by such luminaries as Nyholm; Greenwood & Earnshaw; and Cotton, and it has appeared in notable chemistry-related publications, and numerous other publications, then it is good enough for an article title.

Thank you, —- Sandbh (talk) 06:50, 10 May 2023 (UTC)Reply

One equally finds in notable chemistry publications "p-block metals" to talk about roughly this set, e.g. one, two, three, four, five, six. G&E doesn't even say "post-transition metal" but "post-transition element" and "B sub-group", according to your quote. It does not seem clear to me if "p-block metal" or "post-transition metal" is more common (or if they are actually singular terms as opposed to intersections of "p-block" or "post-transition" with "metal"), and the area being talked about is strictly speaking wider than either of those suggest: p-block raises questions about group 12 (sometimes included comparatively), and post-transition raises questions about aluminium. So they do not quite correctly delimit the scope of the article. Double sharp (talk) 14:13, 10 May 2023 (UTC)Reply

@Double sharp: thank you.

None of the authors of the six PBM examples provided have the reputation of a Nyholm or a Cotton; or Deming who first used the PTM term AFAIK.

G&E’s reference to Bi as a post-transition element is quite accurate; the nonmetals in the p-block are likewise post-transition. The set “B-subgroup metals” is a redundant expression following the introduction of the 1-18 group numbering scheme in 1988.

Searching Google Books and Google Scholar for post transition metal/s or post-transition metal/s yielded about 15,300 hits, and for PBM about 6,500 hits.

Searching ACS Journals and RSC Journals gave 1,541 results for PTM and 845 for PBM.

I hadn’t previously appreciated these metrics.

p-block metals by definition, and as you note, cannot accomodate group 12. Post-transition metals can accomodate the group 12 metals given IUPAC notes the transition metals are sometimes regarded as finishing at group 11.

Post-transition metals accommodates Al, as a group 13 metal. Excluding Al as a PTM raises the question of what sort of metal it is and results in less-used sets such as pre-transition metals.

p-block metals can be regarded as a subset of post-transition metals in a manner somewhat similar to the refractory metals being a subset of TM.

I’m not asking you to support the proposal; I’m only requesting you to withdraw your oppose.

—- Sandbh (talk) 01:35, 12 May 2023 (UTC)Reply

Your third-last paragraph operates on the assumption that these categories have to somehow cover every element. This is certainly not the case. (And it's not so long ago that I had to explain that point.) The 2011 Principles of Chemical Nomenclature (p. 9) from IUPAC no longer mention the possibility of excluding group 12 from the transition metals. And finally, it's not about what only the biggest names said (noting also that Deming is hardly evidence of recent usage), but of what chemists as a whole say, which you thankfully (albeit self-contradictingly) get at by counting Google hits. Roughly 2-to-1 ratios do not seem that decisive when G&E prove that sources might very well use multiple terms for roughly the same set. Double sharp (talk) 14:32, 13 May 2023 (UTC)Reply

@Double sharp: No, these categories do not have to somehow, necessarily cover every element—unless an individual author chooses to do so, as some do and some do not.

The Principles of Chemical Nomenclature: A Guide to IUPAC Recommendations 2011 edition that you mention, are guidelines only. As noted at p. 4, the colour books remain the principal nomenclature documents. The Red Book comment that the transition elements span Groups 3 to 12 or 11 thus remains extant.

I mentioned Deming since he appeared to be the originator of the term. His reputation does not hurt.

At no time have I claimed that post-transition metals is a “decisive” categorisation.

I have instead claimed that post-transition metals is the most common term for the metals in question and could sustain an encyclopaedic article on that basis, at the same time noting the range of alternative names for the subject metals, as per the G&E example, and their sometimes or occasionally varying membership. --- Sandbh (talk) 07:23, 14 May 2023 (UTC)Reply

I agree with your first paragraph. But that means that your argument Excluding Al as a PTM raises the question of what sort of metal it is and results in less-used sets such as pre-transition metals doesn't necessarily hold: an author might well decide that Al is out of scope, or that it should be treated with some other set (possibly not even given a name).
True, but it's nonetheless somewhat interesting that IUPAC does not seem to think that the exclusion is worth mentioning in its guidelines (despite the fact that it would only have taken a single sentence to mention it), even if it is technically still on the books.
The originator of the term "transition metal" (Charles Rugeley Bury) didn't think Y–Tc and Lu–Re were transition metals. So I do not think looking at the terms' originators is a strong argument; we now know more than they did, and today's chemists naturally sometimes differ in usage from them.
Nonetheless, checking Ngrams does agree with your statement that this is the most common term for this inherently fuzzy set. And although it makes somewhat of a contradiction, some authors do after all include Al as a PTM. So I have withdrawn my oppose and replaced it with a support !vote. Double sharp (talk) 17:55, 14 May 2023 (UTC)Reply
The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Updated image in lede

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Further to the previous discussion (above), and as flagged, I' ve updated the image in the lede showing the location of the post-transition metals.

Some adjustments to the main body of the article to follow. --- Sandbh (talk) 04:19, 31 May 2023 (UTC)Reply

It turns out, unless I have missed something, that I will not have to make any adjustments to the main body of the article, since this is where all of the extras have already been mentioned. --- Sandbh (talk) 07:06, 31 May 2023 (UTC)Reply