Talk:Nonmetallic material

Feedback from New Page Review process

I left the following feedback for the creator/future reviewers while reviewing this article: Please expand this quickly. At present this is just a dictionary definition,so should either by draftified or AfD'd. It also is not clear how this will be an improvement on existing pages, the quote from Mott is trivial and not standard. My personal opinion is that it is better to write a coherent sandbox first.

Ldm1954 (talk) 22:10, 11 June 2024 (UTC)

Adding, this article currently is not about nonmetals in physics, in fact I think it is largely inaccurate. Perhaps ask @Johnjbarton to rewrite it for you. Ldm1954 (talk) 22:30, 11 June 2024 (UTC)

@Ldm1954: Thanks for your interest. I've removed your posts to my talk page as I find it unhelpul to spread the conversation over two pages.

I've been endeavouring to bring the nonmetal article up to FA standard. To maintain clarity and focus, the nonmetal article is devoted to the chemistry-based conception of nonmetals.

That said, to cater for alternate conceptions of nonmetals, there is hatnote at the top of the nonmetal article referring to Nonmetal (astrophysics) and Nonmetal (physics).

While one might think a nonmetal is a nonmetal is a nonmetal, regardless of the field of science, this doesn't occur. In astrophysics, only H and He are nonmetals, all other elements being regarded as metals. In physics, C and As are metals, whereas in chemistry they are routlinely regarded as nonmetallic elements.

You further asked:

"Why are you only using nonmetal, semiconductor etc for elements? Is GaAs a nonmetal -- of course it is. Please be general, not just for elements."

Because the reliable source did so. That said, I've added another source (Edwards et al.) that applies nonmetal, semiconductor etc more generally, and placed this first. The narrower source is now second.

--- Sandbh (talk) 08:12, 12 June 2024 (UTC)

Some points:

• New Page Review sends the originator a message and includes it on the talk page. You should put in a request to the NPR project talk if you feel this is inappropriate.
• As a grey-haired academic with a degree in chemistry, another in physics and more than enough pubs, sorry but your comments are incorrect. In terms of conduction diamond is a large-gap insulator and graphite is a semimetal, and As is an insulator. Hydrogen is metallic under pressure.
• In metallurgy and mechanical engineering graphite is a non metal.

The definition you are using is the electropositive/negative one we teach high school students and in intro chemistry, that needs to be clarified -- I know chemistry! Ldm1954 (talk) 08:39, 12 June 2024 (UTC)

@Ldm1954: Thanks.

I wasn't aware of New Page Review. So noted, and no problem.

I don't understand the relevance of diamond being a large-gap insulator (correct) and graphite being a semimetal (correct). Your expertise has let you done if you believe As is an insulator. It isn't—it's a semimetal. The fact that hydrogen may be metallic under some colossal pressure is not relevant to the ordinary conception of it as a nonmetal.

There is no definition of a nonmetal using electronegativity in this article. Could you please add any concerns about this to the Nonmetal talk page? --- Sandbh (talk) 12:13, 12 June 2024 (UTC)

You are correct that bulk As is metallic, I must have misread a quick check. I have corrected this stub. Ldm1954 (talk) 13:13, 12 June 2024 (UTC)

Article notability disputed

Google Books and Google Scholar together return a total of three hits for the search term, "Nonmetallic compounds and elements".

Undoubtedly, the notion of "Nonmetallic compounds and elements" is understood, but not as an integrated topic in a sufficiently cohesive set of reliable sources.

Wikipedia's notability guidelines require that topics have significant coverage in reliable, secondary sources that are independent of the subject. Just three hits suggests that the term "Nonmetal compounds and elements" is not widely discussed or recognized as a distinct topic in academic fields. --- Sandbh (talk) 13:45, 16 June 2024 (UTC)

This is not an issue. The additional phrase "compounds and elements" is there for disambiguation purposes, to distinguish it from other nonmetal articles. IMO, this is not the best title for the article, but by disputing notability, what is proposed here amounts to deletion, not a rename discussion. YBG (talk) 21:32, 16 June 2024 (UTC)

@YBG: Well, yes, it is an issue. If it's there for disambiguation purposes, then it needs to be a list, not an encyclopedic article. And it ought to be Nonmetal (disambiguation) which, of course, already exists, hence the current mess due to precipitous action.--- Sandbh (talk) 13:44, 17 June 2024 (UTC)

@Sandbh- I believe you misunderstood me. I was not saying this article is a disambiguation page. I was saying that the title is an attempt to disambiguate this article from other articles about other senses of "nonmetal". Just as "(planet)" serves to disambiguate the title of mercury (planet), so "compounds and elements" serves to distinguish this article from the other one. Now I happen to think "nonmetallic substances" would be a better title, but that is a different thing. YBG (talk) 02:17, 18 June 2024 (UTC)

Proposal to rename to "Nonmetallic"

According to the Ngram viewer and Google Scholar, "Nonmetallic" is notable. It must be true. It is a confusing name, but that does not seem to be a criterion here. Johnjbarton (talk) 16:04, 21 June 2024 (UTC)

Rename, just do it please Ldm1954 (talk) 22:47, 21 June 2024 (UTC)

According to WP:NOUN, Nouns and noun phrases are normally preferred over titles using other parts of speech; such a title can be the subject of the first sentence. As stated before, my preference would be Nonmetallic substance, but I am open to other ideas. I recognize that this title would expand the scope to include the vernacular usage of the term, but this would only increase the article be a few paragraphs. YBG (talk) 03:05, 22 June 2024 (UTC)

Nonmetallic material(s) appears more in ngrams. YBG (talk) 03:19, 22 June 2024 (UTC)

These are fine. I will just give a bit more time before moving. Johnjbarton (talk) 03:50, 22 June 2024 (UTC)

They are all fine with me (travelling) Ldm1954 (talk) 03:59, 22 June 2024 (UTC)

Disputed cite: A nonmetal has a gap

The general definition section starts...

"A nonmetal has a gap in the energy levels of the electrons at the Fermi level."

...citing chapter 19 of Ashcroft & Mermin's Solid State Physics (1976).

A&M chapter 19 says no such thing.

Alternatively, please provide the page number where they do.

They mention "nonmetals" twice in their 826-page book—on p. 2 and p. 60—and neither of these say anything about a nonmetal having a band gap. --- Sandbh (talk) 01:07, 28 June 2024 (UTC)

@Ldm1954: I manually reverted your edit [1]in which you removed the disputed cite tag for the following reason:

"Added Chpt 8 as well. This is clearly stated in the description, albeit not in those precise words but the same meaning, dispute was inappropriate."

Your reasoning is in breach of WP:NOR, no original research. The cited source does not explicitly makes the statement concerned i.e. that "A nonmetal has a gap in the energy levels of the electrons at the Fermi level." — Sandbh (talk) 13:31, 29 June 2024 (UTC)

@Ldm1954: After casting around, I feel that the following extract represents a good citable source for a physics-based definition of a nonmetal:

Materials are classified as metals or nonmetals depending on the behaviour of their conductance as temperature tends to absolute zero. For nonmetals, conductance tends to zero; for metals, it tends to a finite value. This can be rationalized given their electronic band structures. In nonmetals, the energy bands are either completely filled or completely empty, and in metals, are at least one band is partially filled." (p. 25-2)

Zabet-Khosousi J & Dhiriani A-A 2016, Coupling in metallic nanoparticles: Approaches to optical nanoparticles, in Sattler KD, Handbook of Nanophysics: Nanoparticles and Quantum Dots, CRC Press, Boca Raton, ISBN 978-1-4-200-7545-8, p. 25-2

I like this extract for its explicit use of the terms metals and nonmetals, in the same passage. That, and what Mott wrote. How does this look to you?

A quibble could be the expression "it tends to a finite value", depending on what the authors meant by "tends to". I understand that only about 1 in 5 metals show superconductivity in bulk form and ambient pressure. That 4 in 5 don't would appear to support a general tendency of showing a finite value.

--- Sandbh (talk) 06:11, 3 July 2024 (UTC)

@Johnjbarton: Fyi. --- Sandbh (talk) Sandbh (talk) 06:12, 3 July 2024 (UTC)

Direct quote from The Classification of Stars

@Ldm1954 and Headbomb: Before considering an RfC I'd like to see if we can resolve the disagreement over this quote between ourselves. The full quote is:

"'Metals' (a term which is used very equivocally). Stellar interior specialists use 'metals' to designate any element other than hydrogen and helium, and in consequence ‘metal abundance’ implies all elements other than the first two. For spectroscopists this is very misleading, because they use the word in the chemical sense. On the other hand photometrists, who observe combined effects of all lines (i.e. without distinguishing the different elements) often use this word 'metal abundance', in which case it may also include the effect of the hydrogen lines. It is important to make sure in each particular case what the author really meant."

The source is Jaschek, C; Jascheck, M (1990). The Classification of Stars. Cambridge: Cambridge University Press. p. 22. ISBN 978-0-521-26773-1.

Both of you have raised concerns about the last and first and last sentences of the quote to the effect that, "This is editorializing, and shouldn't be done", and "original research and verging on academic dishonesty."

There is no editorializing, OR or academic dishonesty applicable in the case of quoted content from a reliable source. — Sandbh (talk) 08:13, 30 June 2024 (UTC)

To Sandbh and Headbomb, I am going to reverse my comment a little as I had misunderstood who was doing what. The full quote has those two sentences so in a sense they are appropriate, as Sandbh is arguing. However they are both clear editorializing by Jaschek & Jaschek which is definite not appropriate, similar to Headbomb's edit.

I did not react when Sandbh added that paragraph as I thought it was harmless. However, on further reflection and reading the relevant pages on Google Books I think it is better to remove the whole paragraph. If included then their definitions of heavy elements, lanthanides etc should be included for context and rigor, a vast digression. Further, and most critically, they cite no sources for their statements which they attribute to others/a community. This is certainly editorializing and, IMO, should not be in any text, just as it is not allowed in Wikipedia. In many cases the rules are universal.

I don't see that paragraph as adding any useful information, so a propose Delete. Ldm1954 (talk) 08:54, 30 June 2024 (UTC)

I don't necessarily object to having a quote (with the irrelevant bits removed at least), but you are right that it doesn't really add anything to what's already there. Headbomb {t · c · p · b} 09:21, 30 June 2024 (UTC)

@Ldm1954 and Headbomb: Thanks for contributing to the discussion.

Ldm1954, I note your misunderstanding, which of course can happen from time to time.

Editorialising is a WP concept, referring to editorializing by WP editors.

It does not apply to reliable sources.

In this context, asserting that Jaschek & Jaschek are editorialising "which is definite [and] not appropriate", is meaningless.

Carlos Jaschek, an astrophysicist, and Mercedes Jaschek, a stellar astronomer and spectroscopist, are matter-of-factly laying out the sitation when it comes to the conception of what a metal is in their respective fields. For convenience, here's what they say:

'Metals' (a term which is used very equivocally). Stellar interior specialists use 'metals' to designate any element other than hydrogen and helium, and in consequence ‘metal abundance’ implies all elements other than the first two. For spectroscopists this is very misleading, because they use the word in the chemical sense. On the other hand photometrists, who observe combined effects of all lines (i.e. without distinguishing the different elements) often use this word 'metal abundance', in which case it may also include the effect of the hydrogen lines. It is important to make sure in each particular case what the author really meant.

J&J's introduction to this extract is:

"Since terminology has not always been clear, we summarize brielfy the most frequent groupings of elements."

If their paragraph on metals is included then there's no need to include their definitions of heavy elements, lanthanides etc since these topics are not relevant to the scope of the article.

The extract from J & J adds useful information by nuancing the understanding of metals in astronomy and related fields.

Could you please reconsider your positions. --- Sandbh (talk) 06:55, 1 July 2024 (UTC)

@Sandbh, I have full access to the book, as perhaps does @Headbomb. Editorializing in articles without support Is inappropriate, it does not matter whether it is on Wikipedia or in a book. It adds nothing extra, the key point is in the earlier paragraph about Fraunhofer and how his work was interpreted by Bunsen etc. As Wiki editors we don't just use sources, we have to gauge them for reliability, relevance and accuracy just as, for instance, top newspapers do. Ldm1954 (talk) 07:18, 1 July 2024 (UTC)

N.B. Sandbh, the rules in Wikipedia about sourcing are not very different from the rules in academia for student term papers, theses, journal articles etc, see for instance this article at Yale. Ldm1954 (talk) 08:05, 1 July 2024 (UTC)

@Ldm1954: I've raised the question at WP:ASTRONOMY. --- Sandbh (talk) 04:45, 2 July 2024 (UTC)

General definition: Citing Chemistry of the Non-Metals by Ralf Steudel

@Ldm1954: Steudel's definition of nonmetals is somewhat misleading in that he defines them as follows:

The strictest criterium to define nonmetals in contrast to metals is the electric conductivity. Typically, metals show a finite conductivity at ambient conditions, whereas the conductivity of nonmetals is close to zero. With this definition, 23 of the known chemical elements are nonmetals, and these are the subject of this textbook, namely hydrogen, boron, carbon, silicon, germanium, nitrogen, phosphorus, arsenic, the chalcogens, that is, oxygen through tellurium, as well as halogens and noble gases.

OTOH, elsewhere in his book he treats carbon as a nonmetal, even though the conductivity of graphite exceeds that of some metals; and he treats arsenic as a nonmetal even though arsenic is a metallic conductor, with a conductivty exceeeding that of some other metals.

His reference to the chalcogens as "O through Te" is incorrect. "Chalcogens" is the name of Group 16, including Po and Lv, where Po is a metal and Lv is expected to be the same

His reference to the "halogens" is incorrect, since "halogens" is the name of Group 17, including At and Ts, both of which are expected to be metals. --- Sandbh (talk) 05:05, 2 July 2024 (UTC)

My apologies, but I do not think it is appropriate to selectively criticize a textbook which you are already citing. If there are multiple views then this should be clearly explained in a page, which is the current text. No definition is given priority, all are included (hopefully) with a neutral point of view.

In fact the definition of a metal via conductivity has a range of flavors as nicely described in Fumiko Yonezawa book which is where the Mott quote comes from. The key is whether there are states at Ef, which is equivalent to Mott's T=0 form, positive resistivity with T (if no anomalous lattice variations) etc. Ldm1954 (talk) 09:31, 2 July 2024 (UTC)

Honestly, I'm getting pretty fed up with this incessant obsession over what nonmetals are. It's extremely simple. Define what a metal is. A non-metal is not that. In practice, this refers to semiconductors and insulators. If you want room temperature elements only, it's those at the right handside of the periodic table, plus hydrogen. Headbomb {t · c · p · b} 16:07, 2 July 2024 (UTC)

100% in agreement with Headbomb Ldm1954 (talk) 16:23, 2 July 2024 (UTC)

Thanks Ldm1954. I feel it's OK to discuss a cited source in the spirit of academic debate, shared learning, and our endeavours to improve article quality. Electrical conductivity is mentioned four times in the list of 32 properties that have been used in attempts to distinguish metals and nonmetals. --- Sandbh (talk) 07:17, 3 July 2024 (UTC)

Why do you expect a monograph that's not about radiochemistry to consider polonium and astatine in detail? I daresay that in practice most chemists' experience with the chalcogen column ends with tellurium. Steudel is simply writing appropriately considering the focus of his book.

And as previously explained to you, Steudel understands allotropy. In fact he mentions the graphite thing for why applying the distinction to elements (as opposed to simple substances) is somewhat arbitrary (p. 266). Carbon and arsenic are common elements that have nonmetallic allotropes, so it's natural for him to include them for completeness. Did you expect him to write what's essentially a general-chemistry book without talking about carbon? Double sharp (talk) 03:28, 3 July 2024 (UTC)

Well, I didn't write that I expected Steudel to consider Po and At in detail. I did refer to his odd use of nomenclature. After 5 editions I would've thought that this could've been brought up to scratch.

On page p. 266 Steudel writes, "Of the elements of Group 14, carbon, silicon and germanium are typical nonmetals. The latter two, however, already show semiconductor properties in the solid state and the higher homologues tin and lead are metals."[Note 3]

Note [3] says, "This distinction is – as noted before – mostly arbitrary: graphite does show many of the hallmarks of a metal (e.g., conductivity), while α-tin is nonmetallic in most regards." It's odd that for graphite, its conductivity is a hallmark of metal, yet for α-tin, which is a semi-metal in the same sense, its conductitivity is not mentioned as the hallmark of a metal.

If he noted before that "This distinction" is mostly arbitrary, I was not able find any such mention.

Something I did not notice previously: On the same page as his "strictest criterium" to define nonmetals (p. 154), he writes, "All nonmetals, however, show more or less pronounced semiconducting properties at elevated temperatures (depending on the size of the band gap)."

So, is helium supposed to show semiconducting properties at elevated temperatures?

Still earlier, he writes:

"The ALLRED-ROCHOW electronegativities of the [main group] nonmetals are larger than 1.8, those of the metals are smaller than 1.5 and in the range 1.2−1.8 elements are found that exist as metallic and nonmetallic allotropes (metalloids)."

By this criterion, Be 1.58 , Al 1.61, Ga 1.76 and In 1.66 are metalloids; and Sn 1.82 and Sb 1.98 are nonmetals. Most peculiar.

--- Sandbh (talk) 07:31, 3 July 2024 (UTC)

It's not that odd for superheavy-element specialists to question whether Og is really a noble gas. This may be something similar, since Po and At are both (1) not investigable in most labs and (2) behave quite differently from their lighter congeners in many ways. Judging by articles like this one, if you do get chemists to think about astatine's position, they often do start admitting that it might not really be worth calling a "halogen". (Though I suspect that some of the problems may also be due to the fact that especially At can only be investigated under ultratrace conditions. Ultratrace iodine chemistry is already noticeably different from the situation at normal concentrations, because the equilibrium for the hydrolysis of I₂ starts noticeably favouring HIO instead of I₂.)

Alpha-tin was long thought to be a semiconductor, which could explain the statement. The others are indeed oddities, but I suppose such lapses on topics that aren't too relevant to the main point of the text are not unheard of, and are not fatal to reliability when it comes to the source's actual main topic. (For example, I assume that Steudel was thinking about the nonmetals that form condensed phases. To make it true for helium, you'd have to severely pressurise it first, and then it would actually be a correct statement.) Double sharp (talk) 08:50, 3 July 2024 (UTC)

Feedback on proposal (pro form crosspost)

Sandbh has made a suggestion about multiple articles renaming at Nonmetal proposal which would effect this page. I (Ldm1954) think it has some merit as a start to break an impass about names and content. As a first step I have suggested combining three of the articles proposed by Sandbh on materials, metallurgy and physics into one as they are the same. If interested, please vote either Accept Merge or Reject Merge at Nonmetal proposal. One small step to break the impass. Ldm1954 (talk) 07:30, 4 July 2024 (UTC)