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)

@Ldm1954 I appreciate your concerns, but I’d like to clarify something about WP editing norms, as I understand them.

WP encourages bold editing—consensus is typically reached after edits are made, not beforehand. The WP:BRD cycle—bold, revert, discuss—is designed to allow exactly this kind of editing rhythm: if an edit is reverted, the next step is discussion, not a presumption that prior consensus was required.

Thus, consensus is not required before making an edit. If it were, the entire platform would grind to a halt. Wikipedia’s open model is built on the principle of “edit first, discuss if reverted.” Saying “consensus is required before editing” flips the model on its head.

In this particular case your single revesionary edit revereted seven of my edits: [1];[2];[3];[4];[5];[6];[7]

Of these edits of mine which you reverted:

#1 was reasonably revereted as you posted an explanation for it, thank you, on the Nonmetal talk page, here. Accordingly, I intend to take up the discussion there. The edit by me that you reverted was made in response to User:Headbomb's comment here: "This section is so wrong it needs to be rewritten / purged"

#2 undid the elimination of a redundant {{clear}} tag. Accordingly, I intend to re-revert.

#3 is associated with reversion #1, which I said I'd take up on the Nonmetal talk page.

#4 undid the elimination of a redundant {{clear}} tag. Accordingly, I intend to re-revert.

#5 undid a "dubious" tag removal, with the basis of the removal explained by me on the Nonmetal talk page, here. Accordingly, I intend to re-revert.

#6 undid some adjustments to the lead image legend notes, with result that the lead image and its legend notes are now mismatched. Accordingly, I intend to re-revert, and post a separate discussion to the Nonmetal talk page about the basis for the adjusted legend notes.

#7 undid the addition of a comma in the lead sentence of the article after, "In the context of the periodic table". As a grammatical improvement, I intend to re-revert. --- Sandbh (talk) 12:14, 13 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)

So many things are going on here. I agree with many points made here. I'll start with these then come back to what I think is a more important and difficult problem with the article.

• Focus on secondary references that discuss specifically "Nonmetal". Not things which we think are nonmetals, but the category definition.
• Modern scientific definition should be presented. If more than one, then proportional.
• History of the categorization should be presented as history. If the level of detail seems too much, split and summarize.

Now the hard part: too much of this article is about "nonmetals" and not about "Nonmetal". The article seems to force fit the category into the form of many articles about specific elements, eg Lithium or Boron. So then it needs to fill out content about "Abundance" and "Uses". Lacking secondary sources, this exercise becomes a pile of stuff. In this regard the article seems better than it was in the past.

Finally I suggest specific content discussions rather than broad generic and personal ones. I gather than these recent Talk page posts are related to content around "Suggested distinguishing criteria" which was deleted, re-added, re-deleted, but AFAICT not discussed. Johnjbarton (talk) 22:52, 7 April 2025 (UTC)

A couple of items to please bear in mind:

1. As the hatnote at the top of the Nonmetal article makes clear:

"This article is about the chemical elements that are not metals. For other meanings, see Nonmetal (disambiguation)."

2. In a periodic table context, the definition of metal/nonmetal remains somewhat contentious since there is no universal agreement on which elements are metalloids, with the exception of the elements commonly recognised as metalloids (B, Si, Ge, As, Sb, Te) which are also instead sometimes recognised as nonmetals on account of their predominately nonmetallic chemistry.

@Ldm1954: I saw your ping, thank you, re "@Sandbh will you also accept this as something to be done first?" thank you. I'll get back to you on that one. Sandbh (talk) 12:30, 8 April 2025 (UTC)

@Ldm1954: Further to your ping, I appreciate the idea of improving reference accuracy. However, it’s worth noting that many of the earlier concerns about citations in the “Dubious cites” section—do not hold up to scrutiny. Thus, of 21 items only two were genuinely problematic, and the prior assessment of 18 edits produced a similar outcome. This suggests that most of the claims regarding citation inaccuracy were themselves unfounded.

That said, all editors are of course welcome to check and improve references as part of the normal editorial process. As I understand it, there is no precedent or procedural expectation in Wikipedia that disputed or allegedly inaccurate citations must be vetted by a third party before further editing proceeds. Genuinely dubious citations are normally dealt with through established editorial practices—either being removed, corrected, or queried using appropriate tags. Where relevant, the editor who originally added the citation may respond to a query or supply a replacement. This reflects Wikipedia’s collaborative and iterative editing model, rather than a formal arbitration system.

If there are still specific claims or citations under dispute, the talk page remains the appropriate venue for discussion. I presume that the way forward in improving the article—as has always been the case—rests on evidence, reliable sources, and presumptive consensus, without introducing unnecessary procedural barriers to progress. Sandbh (talk) 11:23, 17 April 2025 (UTC)

Proposal to delete section "Abundance, extraction, and uses"

I propose to delete the section "Abundance, extraction, and uses" in two stages. First reduce the section to just that content with reliable sources discussing "Nonmetal" category. Second assess the result to create a new section name or possibly nothing. Please reply to delete or keep. Johnjbarton (talk) 22:56, 7 April 2025 (UTC)

Delete.

1. Abundance is related to Z and nuclear synthesis, so has no connection to any chemical classification.
2. Similarly there is no general connection between extraction and the classification. There is some connectivity to whether they are gasses or solids etc, but not all elemental nonmetals are gasses at STP.
3. The uses section can never be encyclopedic. Maybe in the lead one can say that they are used in almost everything, and leave it at that.

Ldm1954 (talk) 12:11, 8 April 2025 (UTC)

Also, the uses all depends upon the properties of the final compound/alloy used, only weakly on not those of the element(s). There are weak generalizations such as "compounds with oxygen are good for high temperature applications", but too many exceptions (superalloys and refractory metals as a couple). Ldm1954 (talk) 12:42, 8 April 2025 (UTC)

Keep. I've listed my reasoning hereunder. Sandbh (talk) 13:03, 8 April 2025 (UTC)

I would be interested to hear opinions from @YBG, Headbomb, and Double sharp: about the proposed deletion. So far it is two votes for, one against. It would be good to have a more general consensus before moving forward to avoid edit wars. Ldm1954 (talk) 17:22, 14 April 2025 (UTC)

Keep. These subsections demonstrate the variety that exists within the class of nonmetallic elements. Perhaps I am mistaken, but the proposed deletion seems to be based an the idea that the only thing that belongs in this article are those things which nonmetals all share in common and which distinguish them from metals.

However, all three subsections would benefit from comparing and contrasting metals and by reducing factoid clutter.

• Abundance: I distinguished metals and nonmetals in the chart; even better would be adding two cells to each row, one for "other nonmetals" and another for either "all metals” or "other metals". Delete the Xe factoid or move it to xenon. I note in passing that if abundance is tied to Z, where have all the light metals gone (cue Pete Seeger).
• Extraction: Say something about (nearly?) all metals are extracted mostly from solid ores whereas only half of the nonmetallic elements are - primarily the metalloids and the nonmetals adjacent to them. Drop the history about S or move it to sulfur.
• Uses: Trim this section severely. No need to be exhaustive; just enough to show their great variety of uses which I suspect is related to the great variety in their physical and chemical properties. Figure out a way to show that the metals as a set show greater similarity and less variety of uses compared to NM.

— YBG (talk) 10:52, 17 April 2025 (UTC)

@YBG I am OK with your suggestions as a middle ground. I trimmed some opinion and weasel, leaving a short Xe. I also trimmed the Uses. I did not add anything about metal extraction as that is certainly off-topic. @Johnjbarton, are you OK with this as a middle ground?

N.B., the whole document has a lot of WP:Weasel. I removed some today but there are more. Ldm1954 (talk) 12:26, 17 April 2025 (UTC)

I will ask the same question again: are there any, any reliable sources that propose a relationship between "nonmetal" and abundance, extraction or use? To propose a relationship as we are here is original research.

We have numerous articles on abundance of the elements, including Abundance of the chemical elements, Abundance of elements in Earth's crust, Big Bang nucleosynthesis with many reliable sources cited for many physical characteristic that may influence abundance. Do any of these include "nonmetal"? The abundance of the noble gases is a notable topic because sources exist that discuss that topic. Not so for nonmetals.

Nothing about "nonmetal" figures in the extraction of elements. What counts are myriad other issues. Gases are distilled. Most elements, both metal and nonmetal, are extracted with a combination of mining and chemistry unique to the element.

Similarly, uses. Elements are used for their unique properties, nothing about them being a nonmetal element is used in the choice. Most of the "uses" listed do not even use elements in elemental form.

It's really easy to prove me wrong: provide a source. That is the bar we've set for ourselves throughout Wikipedia and we should not set it aside to create a false parallelism to other articles on elements. Johnjbarton (talk) 15:31, 17 April 2025 (UTC)

It is not necessary to provide a reliable source proving a relationship between "nonmetal" and abundance, extraction or use because these sections do NOT propose a relationship like that. Although this article covers the concept of "nonmetal" per se it also rightly includes an overview of the individual members of this smallish set. As such it is entirely appropriate to include some details of the breadth and depth of those individual elements. It is descriptive, not predictive and does not require a RS with the specific word "nonmetal" because we are not claiming a relationship between nonmetals in general and abundance, source, or uses. All that is needed is references to support the relationships claimed in the article, between various specific metallic elements and abundance, source, and uses, which is exactly what the article has.

If we were to claim a general relationship like

because these elements are nonmetals therefore they are conduct electricity

or like

because these elements conduct electricity therefore they are nonmetals

we would require a RS with the word "nonmetal" to support such a generic relationship. Similarly if we claim a relationship like

because these elements are nonmetals therefore they vary greatly in appearance (being colorless, colored or shiny)

or like

because these elements vary greatly in appearance (being colorless, colored or shiny) therefore they are nonmetals

we would require a RS with the word "nonmetal" to support such a generic relationship. However we merely state

Nonmetals vary greatly in appearance, being colorless, colored or shiny

and so we do NOT need a RS that states this exact fact containing the word "nonmetal" in it. All we need is RS showing that specific nonmetals fall into these categories.

These sections are NOT proposing a relationship between the generic concept "nonmetal" on the one hand and abundance, source, and uses on the other. These sections describe the variety of abundance, source, and uses amongst the set of nonmetallic elements, and for this I believe the present RS are adequate.

Yes, it would have nice to have better RS, and I would welcome such if for no other reason than to reduce the number of refs and the number of referenced pages and the number of "passim"s. I would also welcome additions to these sections that compare and contrast this descriptive information of the set of nonmetallic elements with the comparable information for the set of metallic elements.

To summarize summary, we do NOT need to provide the type of RS that @Johnjbarton suggests, proving a relationship between "nonmetal" and abundance, extraction or use because these sections do NOT propose a relationship like that.

— YBG (talk) 05:25, 18 April 2025 (UTC)

Discussion

I respectfully disagree with the proposal to delete this section.

The information it presents—on how nonmetals occur, are obtained, and are used—adds important context and educational value to the article.

While it's true that many uses involve compounds or materials rather than the pure elements, the same can be said of metals. That hasn’t stopped Wikipedia articles on metals, metalloids, or element groups (e.g., alkali metals, halogens, noble gases) from including well-sourced sections on abundance, production, and applications. These topics are commonly treated in introductory chemistry texts and provide meaningful insight into what distinguishes nonmetals as a group.

In fact, the abundance and extraction methods of nonmetals often differ from those of metals because of their nonmetallic properties. For example:

• Many nonmetals are gases and must be separated from air (e.g., nitrogen, oxygen, noble gases);
• Others are extracted from seawater or brines (e.g., chlorine, bromine, iodine);
• Sulfur can be recovered from natural gas and petroleum refining.

Likewise, elemental uses do reflect fundamental properties:

• Nitrogen is used as an inert gas due to its triple bond and lack of reactivity;
• Oxygen is used in combustion and medical settings due to its oxidizing ability;
• Carbon (as graphite or charcoal) is used for conductivity, filtration, or reducing agents.

These are not arbitrary selections from downstream compounds—they are standard examples of how the intrinsic properties of nonmetals shape their presence and roles in nature and industry.

If there are concerns about structure, redundancy, or sourcing, I would support trimming or reformatting. But removing the section altogether would reduce the comprehensiveness and accessibility of the article. The section contributes directly to a rounded understanding of nonmetals—what they are, where they occur, how we obtain them, and what we do with them. These are all questions readers reasonably expect an encyclopedia article to address. Sandbh (talk) 13:03, 8 April 2025 (UTC)

• "These topics are commonly treated in introductory chemistry texts.."

As far as I can determine, this section has no citation to any secondary source that discusses the abundance, extraction or use of nonmetals. Johnjbarton (talk) 15:55, 8 April 2025 (UTC)

Verifying refs in subsection "Abundance"

• Pepin/Porcelli reference on Nobel gas origins, mostly about the challenges of using them in planetary science. End up adding different refs to Nobel gas.
• Zhu on the "missing Xe problem". Added a section to Xenon with this ref and two others.
• Klein and Dutrow on silicates. Add this book as a ref to Silicates
• Cockell's book is not even about abundance, let alone "nonmetal".

Didn't find anything about the abundance of nonmetals because they are nonmetals. Johnjbarton (talk) 22:08, 16 April 2025 (UTC)

Verifying refs in subsection "Extraction"

These are all from Emsley, "Nature's Building Blocks An A-Z Guide to the Elements" "Arranged alphabetically, from Actinium to Zirconium, ...". Similar content with more detail appears in nitrogen, oxygen, and sulfur. Ad the diagram in this section illustrates, the extraction process is not characteristic of nonmetals. The section is just a list of element extractions. Johnjbarton (talk) 22:17, 16 April 2025 (UTC)

Taxonomical history

I made a first pass through "Taxonomical history". I verified most of the refs or deleted them.

I cannot verify the last section "Nonmetals as terminology". Johnjbarton (talk) 02:57, 8 April 2025 (UTC)

Comments:

1. Looks good, short and sweet
2. If the section Nonmetal as terminology is retained I don't think it needs a subsection header, it is a continuation of the previous section.
3. I think a modern definition of metal via band structure has to be mentioned at the end. It does not have to be long as the natural location is in Definition and applicable elements (which may need title wordsmithing).
4. I suggest adding a sentence to the lead on taxonomy so it is consistent with the contents.

Ldm1954 (talk) 12:01, 8 April 2025 (UTC)

I have a draft for the modern definition in User:Ldm1954/Sandbox/Modern terminology. Comments and edits welcome. Ldm1954 (talk) 18:57, 14 April 2025 (UTC)

Proposal to delete section "Types"

Issues:

1. This section starts with a description of various nonmentallic elements which is a duplicate of what is described elsewhere; there is no strong rationale to repeat which elements are being considered another time.
2. The "Noble gases" second repeats what has been mentioned earlier about gas forms, bonding and similar. This adds length but not additional encyclopedic content.
3. Similarly the "Halogen nonmetal" section repeats material. It also has significant inaccuracies in statements about corroision. This is far, far more complex than simple bonding.
4. Similarly the "unclassified" section contains repeated facts, errors on corrosion.
5. All sections have somewhat random facts added that are outside the topic of nonmetals. For instance, that sodium and chlorine form salt is not information that says anything useful about nonmetals in a general and encyclopedic fashion

Ldm1954 (talk) 07:01, 15 April 2025 (UTC)

I oppose the proposal to delete the "Types" section.

I agree with the sentiment expressed in the earlier thread on historical terminology—that if the issue is primarily one of content quality, the better path is to simply improve the section using reliable sources. Deleting the entire “Types” section would eliminate material that is pedagogically useful, reflected in chemical literature, and consistent with the scope of the article.

The claim that the section “adds length but not encyclopedic content” is mistaken. While there may be some redundancy or editorial untidiness, the classification of nonmetals into noble gases, halogen nonmetals, and unclassified nonmetals is a validly encountered framework. These categories:

• Reflect periodic trends and group properties (e.g., reactivity, valency, bonding),
• Aid in understanding the diversity within nonmetals,
• And help readers conceptually organize a set of otherwise disparate elements.

This is chemical pedagogy. If there are errors (e.g., in corrosion-related statements), these should be corrected, not used to justify removing the entire section. Likewise, if certain illustrative examples (like sodium chloride formation) feel out of place, they can be reworded or replaced. Similarly, concerns about duplication can be addressed through judicious structuring and editing of the article.

Per WP:PRESERVE, we should aim to improve rather than discard. And per the spirit of the earlier RfC removal: this is not an intractable dispute that calls for broad community resolution—it is an editorial issue that can and should be addressed by collaborative editing, not by excision. --- Sandbh (talk) 08:16, 16 April 2025 (UTC)

Keep. To understand the set of nonmetals one must not just understand their bare commonalities and the distinctions between them and the other elements. One must understand the taxonomic structure of the set. If there is overlap perhaps it should be reduced, but not at the expense of understanding the divisions and variety within the nonmetallic elements. Compare animal which devotes much more space to its subcategories than does this article. YBG (talk) 09:37, 17 April 2025 (UTC)

OK. I trimmed off redundant material about uses and some weasel/opinion. I am OK to leave this reduced section in its current form. Ldm1954 (talk) 12:09, 17 April 2025 (UTC)

Acknowledgement

Parts of the additional section on modern terminology are based upon text in other pages, mainly Metals, Nonmetallic materials, X-ray crystallography and Electron diffraction. Please see those pages for addition history and credits. Ldm1954 (talk) 14:22, 15 April 2025 (UTC)

Dubious cites?

Good day @Ldm1954:

In Archive 8 of this talk page, there is a section titled Dubious cites (dated 5 August 2024), listing 21 items you posted, along with the comment: “Several inaccurate cites, they all need checking in detail.”

I’ve copied the 21 items and pasted them below the horizontal rule, reviewed them, and provided an assessment of each. Of the 21, only two items—one clearly incorrect, and two partially incorrect (½ + ½ + 1)—can reasonably be considered dubious. This suggests that approximately 90% of your claims do not stand up to scrutiny.

For context, on 20 June 2024, I also assessed 18 edits you made to the Nonmetal article between 10 and 12 June 2024. That review found that just 1½ of those edits were valid, suggesting that roughly 91% were similarly unsupported.

Taken together, these two review exercises—covering 39 claims or edits with a 90% error rate—indicate a consistent pattern of questionable source-checking and editorial judgment. While good-faith editing is always appreciated, repeated issues of this kind—particularly when accompanied by strong editorial assertions—risk undermining the reliability of the article and diverting attention from more constructive improvements. At the very least, this pattern suggests a need for greater caution and more carefully considered contributions in the future. --- Sandbh (talk) 11:14, 17 April 2025 (UTC)

Your opinion is just that. While you are entitled to it, that does not mean that others have to agree with you. I don't. Ldm1954 (talk) 11:18, 17 April 2025 (UTC)

What is needed is an evaluation by a 3rd party. As I look at the stats of @Sandbh's evaluation, about 10% of the refs were rejected. If this is the original author rejecting his earlier work, I find this 10% figure more worrisome than the 90%. The 90% means two editors disagree, hardly surprising. The 10% seems to indicate an editor rejecting his earlier work. Nevertheless, @Sandbh is to be commended for being willing to reconsider and re-evaluate his earlier work.

(Note: I am only speaking in generalities here; I just briefly scanned @Ldm1954's original reports and @Sandbh's responses.)

— YBG (talk) 06:26, 18 April 2025 (UTC)

---

1. Cites of p7 in [21] for "brittle or crumbly" which source does not say. The only relevant information is a discussion of brittleness of nonmetallic materials such as MgO on p270.

   Yes, I agree, and updated the cite on 5 August 2024.

   As to your closing comment, cite 21 in fact states, "Most nonmetallic crystals are brittle at low temperatures but are quite ductile at elevated temperatures, i.e., T > 0.05T_m" (p. 291)

2. Cite of [26] for 1000 atom Se chains, where there is no source cited in the book so it is not a good source.

   The absence of a source in the book doesn’t necessarily make it "not a good source." In compendiums of this kind, it's not uncommon for authors to include observations without formal citation. In this case, the book was easily accessible and written by a physicist, so it seemed to be a reasonable tertiary source for the statement.

3. Cite of [68] for octet rule, where in fact the text says that is not a good approximation and VB should be used (changed)

   The paragraph in question explains a well-established generalisation—the tendency of nonmetals to gain electrons—by linking it to the stability of noble gas configurations, which is both chemically correct and accessible to a wide audience. As far as mention of the duet and octet rules goes, these are long-standing heuristic rules taught at an introductory level to explain why atoms gain or lose electrons. In the case of the noble gases, helium goes with the duet rule, and Ne through Rn with the octet rule.

   There is thus no need to delve into the theoretical underpinnings of chemical bonding via VB.

4. Both As & graphite are semimetals, incorrect statement in Enf

   The footnote in question was:

   "The solid nonmetals have electrical conductivity values ranging from 10⁻¹⁸ S•cm⁻¹ for sulfur to 3 × 10⁴ in graphite or 3.9 × 10⁴ for arsenic; cf. 0.69 × 10⁴ for manganese to 63 × 10⁴ for silver, both metals. The conductivity of graphite (a nonmetal) and arsenic (a metalloid nonmetal) exceeds that of manganese. Such overlaps show that it can be difficult to draw a clear line between metals and nonmetals."

   After your edit it read:

   "The solid nonmetals have electrical conductivity values ranging from 10⁻¹⁸ S•cm⁻¹ for sulfur to 3 × 10⁴ in graphite or 3.9 × 10⁴ for arsenic; cf. 0.69 × 10⁴ for manganese to 63 × 10⁴ for silver, both metals. The conductivity of graphite and arsenic (both semimetals) exceed that of manganese.

   The impact of your edit was to introduce confusion with mentions of "semimetals", and to undermine the point that, "it can be difficult to draw a clear line between metals and nonmetals."

5. The use of an O-level (< 16 years old) text book, i.e. Cambridge O Level Chemistry Book by B. Earl and Doug Wilford is dubious.

   This book represents a reliable source that is within grasp of the general reader. As such there is nothing dubious about it.

6. Citation to Sanderson 1957 quoted a page that did not exist (was the 1967 book meant?). In any case the ref has only been cited twice so removed as it is not really that relevant or accurate.

   The citation was to "Sanderson 1957, p. 229". The article in question is Sanderson J. Chem. Educ. 1957, vol. 34, no. 5, p. 229. The article is called, "An electronic distinction between metals and nonmetals". It is relevant given its subject matter.

7. Temperature coefficient of resistivity is very much older than the table implied, it is in Kittel 1956. Date moved to 1956 (it might be earlier) and a relevant source added. Other dates are probably wrong.

   I choose this 1999 source since it said:

   "Probably the best criterion for distinguishing a metal and a metalloid or semiconductor is the temperature coefficient of thermal and electrical conductivity. With increase in temperature, the thermal and electrical conductivity of a metal decreases, whereas that of a metalloid or semiconductor increases."

   As such, it is quite relevant. That said, Lanzetta and Gavignet (2011, p. 97) credit Sir Humphrey Davy, in 1821, with discovering, "that all metals have a positive temperature coefficient of resistance".

   Lanzetta F & Gavignet E 2011, Thermal measurements and inverse techniques, in Orlande et al. (eds), Thermal Measurements and Inverse Techniques, CRC Press, pp. 95–142

   Upon reflection, it would be better to list the 1821 entry for Davy, and to add a footnote pointing to the 1999 source.

8. Atomic conductance is just electrical conductance in different units; it is redundant so has been deleted.

   Atomic conductance is the conductivity of a block of the substance 1 cm² in cross-section but long enough to contain one mole of atoms of the element. It is a measure of the conductivity of one mole of atoms of the element. It is used by Hill G, Holman J & Hulme PG 2017, Chemistry in Context, 7th ed., Oxford University Press, Oxford, to classify the elements as metals, and as metalloids and nonmetals.

   As such, it is not redundant.

9. The article about "3D conductivity" was misquoted, it is just another rephrasing of the established conductivity argument. Deleted from table.

   Myers writes:

   "There is, of course, only one property which is common to all metals and sets them apart from nonmetals: high electrical conductivity in three dimensions [italics added]...Some texts are careful to point out that graphite is a good conductor of electricity (but this is only in two dimensions, along the planes of carbon atoms)..."

   As such there was no case for the deletion of the "3D conductivity" entry.

10. The claim in the table that Horvath connects critical temperature to metal/nonmetal does not appear in the paper. Hence removed from the table.

    Horvath's figure 1 shows a periodic table including a traditional dividing line between metals and nonmetals. He refers to this as a diagonal line although it has a stair step shape. He writes, "The elements allocated on the left side (metallic side) of the diagonal line, Al, Ge, Sb, and Po, show the highest critical temperatures in their groups (vertical columns of the periodic table)." See his figure 1. Horvath thus connects critical temperature to metal/nonmetal.

11. The cite of Remy (1956) as "Minimum excitation potential" is inaccurate. He gives the standard band structures explanation. Removed.

    Remy wrote:

    "Borelius (1939) has pointed out that all elements with minimum excitation potentials appreciably over 6 e.v. are non-conductors. Those with minimum excitation potentials in the neighborhood of 6 e.v. are semi-conductors, and those with excitation potentials significantly less are metals."

    There was thus no basis for removal.

12. The cite of Mann et al 2000 on configurational energy is invalid. The paper only discusses the d-block elements and makes no claims about metals versus nonmetals in general. The Wikipedia link also makes no such claims. Removed.

    Mann et al. write that, "metals have configuration energies lower than that of silicon, the least electronegative of the metalloids" and refer to "silicon, the least electronegative nonmetal (except for gold which has a CE equal to that of silicon)."

    Mann is thus not invalid and should've been retained.

13. Johnson (1966) does mention physical state, e.g. gas, but then says it is not so good and lists the other standards such as conductivity etc. Hence removed from table as unverified.

    Johnson writes:

    "The metallic or nonmetallic nature of an element is best [bold added] indicated by certain physical properties. The most obvious properties which help us to classify an element as a metal or nonmetal are its physical state, appearance, and malleability and ductility. All elements which are gaseous at room temperature are nonmetals. Liquid or solid elements may be metals or nonmetals…Solid nonmetals are either hard and brittle or soft and crumbly. Most metals, in contrast, are malleable and ductile. These readily apparent physical properties allow one to distinguish between most metals and nonmetals. [talics added] However, for a number of elements, particularly those in the vicinity of the semimetals in Figure 1-1, these properties do not provide an unambiguous classification and other properties must be considered."

    There was thus no basis to remove this citation.

14. Scott 2001 cites page 1781 which does not exist in any edition of the book (250-350 pages). Marked as dubious, perhaps delete later.

    Agree. This cite is erroneous and should be corrected or deleted.

15. Povh & Rosin 2017 has no statements about thermal conductivity on p131. There is a short description on p173, but it does not call this a defining property. Deleted as unverified.

    At p. 131, the authors write, "The high speed of electrons at the Fermi surface is again responsible for the roughly 100 times larger thermal conductivity of metals compared with nonmetals." There was thus no basis for deletion.

16. Brandt 1821, p5 is not even close to discussing metals and opacity. Deleted as very unverified and irrelevant.

    The actual name of the author, as listed in the Nonmetal article, is Brande. At page 5 he writes, "The metals, as a class, are characterized by a peculiar lustre and perfect opacity." The source is thus verifiable and relevant.

17. Beach 1911 appears to have been copied from Origin and use of the term metalloid which has unrelated information. Since this is a very long book, without specific page number etc this source is not verifiable.

    This source is easily verifiable via the Internet Archive. Exactly the same entry is found in the 1903 edition of Beach, here. See the entry for "Metalloid".

18. Harris 1803 provides the standard property list, the text misquoted what is stated.

    Harris says, "…specific gravity is greater than that of any other bodies yet discovered; that they are better conductors of electricity than any other body;"

    The quote said, "... [metals'] specific gravity is greater than that of any other bodies  yet discovered; they are better conductors of electricity, than any other body."

    There was thus no misquote, rather a single “that” was missing, which made no difference to the substance of the quote and which you could’ve easily added.

19. Cyclopaedia: Or an Universal Dictionary of Arts and Sciences (1743) rambles for three and a half pages with statements such as differentiating gold, mercury and silver by how much sulphur is in them, that metals are transmutable into each other etc -- there is a link to an open source. While the statement about "heaviness" is there, it is not the focus of the article. I cannot consider this as a useful source so I am deleting it, whereas Harris 1803 is definitively reputable.

    In its entry for METAL, the source writes "That which distinguishes metals from all other bodies ... is their heaviness ...”. There was thus no basis to delete it.

20. Jones citation is "Jones BW 2010, Pluto: Sentinel of the Outer Solar System" which is definitely not on distinguishing criteria of nonmetals. Marked for the moment as dubious.

    Jones discusses the role of classification in science. There was thus no basis to mark this citation as dubious.

21. Hare and Basche 1836 p310 is cited for inventor Humphry Davy made an important discovery that reshaped the understanding of metals and nonmetals. It says nothing like that on p310. Removed as unverified.

    It is common knowledge that Davy discovered the first of the alkali metals and that, astonishingly for the time, these were lighter than water. As Hare and Basche thus wrote on page 310:

    "Less than thirty years ago, the line of demarcation between metals and other bodies was easily drawn. There was then no known metal which had a specific gravity less than six; and of other bodies, none, of which the specific gravity was as high as five. But the discovery of alkalifiable metallic radicals, having a specific gravity less than that of water, annihilated [italics added] the barrier which had been established on the basis of superior gravity."

    Thus, there was no basis for removing the cite.

--- Sandbh (talk) 11:14, 17 April 2025 (UTC)