Talk:Nonmetal

Timeline accuracy

I don't know who cobbled this together, but the dates don't check out on many things. For instance, the so-called Mott criteria, supposedly suggested in 2020. Work on this goes back to Goldhammer (1913) and Herzfeld (1927). Mott wrote about it in his book in 1990, but he came up with that criteria way back (1961? doi:10.1080/14786436108243318).

And yet we say 2020 because come people wrote a paper using the Mott criterion in 2020.

Utter. Nonsense.

This whole section should be jettisoned until we have actual sources discussing the actual history of metals.

Headbomb {t · c · p · b} 02:11, 6 August 2024 (UTC)

Yup, the dates are horrible and many of the sources don't verify (see my ever growing list #Dubious cites). Plus the most important definition, band structure, is conspicuously absent despite appearing in numerous chemistry texts books. It needs to be there. Ldm1954 (talk) 02:26, 6 August 2024 (UTC)

Yes, the Mott criterion was not first proposed in 2020. The original formulation dates back to Nevill Mott’s 1961 paper ("The transition to the metallic state", Philosophical Magazine, 6:287–309) and has a rich theoretical lineage, including precursor ideas from Goldhammer (1913) and Herzfeld (1927).

The 2020 paper cited in the table does not claim to have originated the Mott criterion. Rather, it applies the existing criterion to the periodic table under ambient conditions, proposing that the dividing line between metals and nonmetals lies at a Mott parameter value of ~0.45, instead of the original ~0.25 value derived for T = 0 K. This represents a recalibration, not a reinvention. The relevance of ambient contitions is set out in the hatnote in the Definition and applicable elements section: "Unless otherwise noted, this article describes the stable form of an element at standard temperature and pressure (STP)"

That said, the article should clarify this distinction to avoid any implication that the criterion was developed in 2020. I've augmented the footnote to this end.

Thanks for catching this — it's an important nuance to get right. Sandbh (talk) 05:50, 4 April 2025 (UTC)

Band structure has been there since Aug 3, 2024, thanks to User: Headbomb. --- Sandbh (talk) 05:59, 4 April 2025 (UTC)

I just shitcanned the whole section as hopeless. Headbomb {t · c · p · b} 20:23, 4 April 2025 (UTC)

I'm glad I took a 7-month editing break from this article.

Leaving behind the contentious timeline table, I have added a trimmed, copyedited and reorganised "Suggested distinguishing criteria" section.

The flow is from conceptual non-agreement, to a single criterion, then to empirical examples: one property; two properties; multiple properties. Sandbh (talk) 04:44, 5 April 2025 (UTC)

Checking citations

@Ldm1954, Johnjbarton, and YBG: I plan to start progressively checking the citations in the article, from #1 onwards, to ensure they support the statements they're attached to. I'll post my findings here, probably in batches of 10 at a time, for transparency and discussion. Looking forward to any input others might have along the way. Sandbh (talk) 04:18, 4 April 2025 (UTC)

Dubious tag: As and Sb

The article currently says:

One widely recognized physical property is the temperature coefficient of resistivity—that is, the way an element’s conductivity changes with temperature. In metals, conductivity typically decreases with increasing temperature, whereas in nonmetals it increases. However, there are notable exceptions. For instance, plutonium, although a metal, exhibits increased conductivity when heated from −175 °C to +125 °C. Conversely, carbon (as its graphite allotrope), often described as nonmetallic, behaves as a semimetal and shows decreased conductivity with temperature. [Atkins et al. 2006, pp. 320–21] Arsenic and antimony, sometimes classified as nonmetals, behave in the same way. [Zhigal'skii & Jones 2003, p. 66]^{[dubious – discuss]}

The reason given for the tag is: "No such statements appear in the more recent 9th and other editions, so unverifiable."

AFAIK, since As and Sb are semimetals in the physics-based sense and do behave in the same manner as graphite, and since there is no 9th edition of either Atkins et al. or Zhigal'skii & Jones, I have removed the dubious tag. Sandbh (talk) 05:11, 5 April 2025 (UTC)

Sandbh, please stop

@Sandbh, sorry but you are again making unilateral changes based upon your own opinion which is not shared. Rather than attempting to seek consensus, for instance by making suggestions in a Sandbox, you are just deleting/editing. This is not how concensus is generated on Wikipedia, so please only make changes for which there is consensus. I am reverting your recent edits. Ldm1954 (talk) 15:45, 5 April 2025 (UTC)

Historical confusion on chemical elements terminology is no longer relevant

Articles on categorization of the elements should reflect 21st century encyclopedic knowledge, not old science.Ldm1954 (talk) 09:10, 6 April 2025 (UTC)

Comment: Definitely not informed enough to present an opinion on this issue, but this RFC appears to very incorrectly presented, neither neutral nor brief. ―Howard • 🌽³³ 22:51, 6 April 2025 (UTC)

I have trimmed the RFC text as requested. Ldm1954 (talk) 23:33, 6 April 2025 (UTC)

Expansion:The pages nonmetal, metalloid and some others dealing with chemical elements have extensive discussion of terminology dating back centuries. Much of this is portrayed as competing views, with those from a century ago being given equal weight to contemporary science. The impression a reader will get is that the descriptions and terminology is confused/confusing. Science moves forward. Before modern quantum chemistry methods the distinction between different elements and materials was unclear; this was even more so back when computers were less powerful than a modern smart phone. Nowadays calculations are routine, and an undergrad can test the chemistry of radioactive transuranic elements as well or better than experiments (with a little guidance to avoid known pitfalls). The definitions of metal/nonmetal/semimental are no longer controversial. Hence I am arguing here that these articles should reflect 21st century knowledge, not obsolete science. Sections that discuss the historical confusion should at most be short, with any extensive description moved into an article or articles on the terminology history, separate from the material we provide the general reader as encyclopedic knowledge. Ldm1954 (talk) 23:31, 6 April 2025 (UTC)

So just fix it. This is not what WP:RFC is for. You've come up with a general content issue, that our material in this article is outdated and perhaps using WP:OR to miscast outmoded views as if competing modern scientific ones. There is no reason for you to not simply edit the article using high-quality modern science sources to clean it up. RfCs are for having the community gather up to resolve an heretofore intractable dispute after attempts to resolve it at the article talk page have failed to come to consensus. It is a process that is expensive with regard to editorial time and attention. I'm removing the RfC tag from this because multiple editors have pointed out that it is not a proper RfC. There's no evidence of prior serious discussion of this with a long-term failure to resolve a dispute about this matter. All I see are you and one other editor taking unrelated potshots at each other without any in-depth discussion of this particular matter at all. So, this thread can perhaps become that discussion, if really needed. But I would suggest that science is clearly on one side of this, and that simply editing the article to agree, per WP:DUE, with that scientific consensus will get the job done without a bunch of blathering.  — SMcCandlish ☏ ¢ 😼  05:38, 7 April 2025 (UTC)

Actually, as I re-read this the impression I have is that the current state of things has developed over a long historical period of flux in nomenclature and categorization. Though I don’t know if the details are accurate, I would be extremely surprised to find anyone disagreeing with this in general. This is, after all, how the scientific method works and how taxonomies develop. This historical perspective certainly belongs in this article, though perhaps not in as much detail as it currently has.

In terms of classifying elements (as opposed to materials in general), I do wonder: What you (@Ldm1954) understand the current scientific consensus to be about the elements commonly called metalloids? Are they a subcategory of nonmetals? Or are they be consider a third super category of elements, on the same level of the hierarchy as the metallic elements and the nonmetallic elements?

WP:PSTS says Wikipedia articles should be based on reliable, published secondary sources, and to a lesser extent, on tertiary sources and primary sources. My understanding is that there is still disagreement about the metalloid elements, but I am open to being corrected in this.

The RfC proposer seems to be arguing that for having no historical info in this article. I disagree; I think that the best ultimate state would be to briefly summarize that history here in a section with a {{main}} link pointing to an article with the full details in all their glory.

However, I oppose doing this immediately because of the current concerns about the whether this section accurately reflects the information in the cited sources. If the details were moved to a separate article before the sources have been checked, I fear it would only serve to hide those problems by moving yo a less prominent article. IMO this would be a bad result.

So what I would like to see is a complete verification of the sources in this detailed historic description by an editor other than the original author with access to the literature (which excludes me). Once that has been done (on this page) and there is some semblance of consensus, then (and only then) would I want to move the details to a subsidiary article.

I am open to moving the details to a subsidiary article first but only if (1) a summary is left behind and (2) we are convinced that the detailed historic narrative will actually get scrutinized.

Any thoughts on this approach? YBG (talk) 06:55, 7 April 2025 (UTC)

@YBG, I very much support the idea of an independent editor checking the references. This will satisfy my concerns. Hopefully other editors such as @Johnjbarton, @Headbomb, @Double sharp and a few others who have expressed concerns will be OK with this. @Sandbh will you also accept this as something to be done first? It is certainly better than the nascent edit war nucleated by the recent edits of @Sandbh and the deletion by @Headbomb. (No accusations; the deletion by @Headbomb was consistent with prior (now archived) talk.) Ldm1954 (talk) 12:14, 7 April 2025 (UTC)

All I'm going to say here, wrt to [articles] have extensive discussion of terminology dating back centuries, is exactly what we should be doing. We are an encyclopedia, documenting the history of concepts and their evolution is critical. Headbomb {t · c · p · b} 13:40, 7 April 2025 (UTC)