Talk:Nonmetal/Archive 3

Complementary pairs (follow-on from previous section)
My biggest concern [about the Nonmetal article] is related to the pairing of nonmetal classes with a “complementing” set of metals.
 * The pairing of nonmetal classes and metal classes is a beautiful and symmetric, but I suspect it is a bit fringe to be so prominently displayed in this article. There are RS listed in the pictures that presumably show that a given author compared a specific nonmetal category with a specific metal category. But the sources are different for each one.
 * Let me draw a comparison. In we see a list of planets and corresponding metals. The entire set of pairings is well attested in RS.
 * But what if I only found one RS that compared the Sun to gold, a different RS that compared the moon to silver, and a third that compared Mercury to mercury, and a fourth that compared Venus to copper, a fifth, Mars to iron, a sixth, Jupiter to tin, and a sixth, Saturn to lead? In this case, I believe it would be violate WP:SYNTH to prominently display the whole set of pairings as though it were some sort of organizing principal.

The pairings of nonmetal categories with metal categories appears to be this same sort of synthesis, and so I say, no matter how beautiful and symmetrical this is, it does not belong in a WP article. I would be very interested to know what other reviewers think of this concern. YBG (talk) 06:22, 21 October 2023 (UTC)


 * ping Graham Beards|Michael D. Turnbull|Jo-Jo Eumerus|Double sharp|Sandbh: Please consider commenting on this. I will consider this concern resolved if either (1) the nominator removes the info about complementary sets of metals, or (2) no other reviewer voices a concern about this, or (3) one other reviewer gives what they (not me) consider is a good reason that this is not a concern. YBG (talk) 13:37, 21 October 2023 (UTC)

I agree with your concern. Not only is each comparison cited to a different source, but the last one (unclassified to transition) is straightforwardly SYNTH (see ref. 158; neither source quoted actually spells out the connexion). Double sharp (talk) 14:11, 21 October 2023 (UTC)


 * ping Jo-Jo Eumerus|Double sharp|YBG: I've added a citation that mentions the four complementary sets. --- Sandbh (talk) 03:55, 22 October 2023 (UTC)
 * WP:NOT says
 * (emphasis added)
 * Citing your own article suggests that someone as well read as you could find no other RS that organizes things this way, which seems to prove my point: this is a novel idea not yet ready for WP. I suggest that it is best to leave it out for now. In a few years, if this organizing scheme is as useful as it is beautiful, other authors will pick it up and it can be included with no objection. YBG (talk) 04:28, 22 October 2023 (UTC)
 * Thank you.
 * There is nothing "novel" in this.
 * The background to the complementing sets is that the pairing of metals and nonmetals, and alkali metals and halogens, forms a foundational technique in chemistry education:
 * ... we focus mainly on the gross structure – the metals are here, the non-metals are there, and so on. Once they have grasped this, you can start to show that there's some order to it. We talk about the Group 1 alkali metals and start to see that they're all similar in some way. Then at the other extreme there are the ...halogens. The idea that the table shows us how to group similar elements starts to come together in this way.
 * Niki Kaiser (2019)
 * Notre Dame High School, Norwich, UK
 * There is a long history in the literature of complementing sets, for example:
 * "What, in general, is the difference between active metals, less active metals, less active non-metals, active non-metals, and inert gases…?
 * --- Friedenberg EZ 1946, A Technique for Developing Courses in Physical Science Adapted to the Needs of Students at the Junior College Level, University of Chicago, Chicago, p. 230"
 * For more recent references there are:
 * "Describe how groups of elements can be classified including highly reactive metals, less reactive metals, highly reactive nonmetals, less reactive nonmetals, and some almost completely nonreactive gases.
 * --- Padilla MJ, Cyr M & Miaoulis I 2005, Science explorer (Indiana Grade 6), teachers's edition, Prentice Hall, Upper Saddle River, New Jersey, p. 27"
 * "Those [elements] classified as metallic range from the highly reactive sodium and barium to the noble metals, such as gold and platinum. The nonmetals…encompass the…the aggressive, highly-oxidizing fluorine and the unreactive gases such as helium.
 * --- Weller et al. 2018, Inorganic Chemistry, 7th ed., Oxford University Press, Oxford, preface"
 * A similar pattern occurs along the periods:
 * "Across each period is a more or less steady transition from an active metal through less active metals and weakly active non- metals to highly active nonmetals and finally to an inert gas.
 * --- Beiser A 1968, Perspectives of modern physics, McGraw-Hill, New York"
 * The pairing of the noble metals and gases is mentioned in no less a reputable source then Wiberg.
 * The pairing of the post-transition metals and the metalloids occurs even in a popular science book by Adrian Dingle (2017) who has written extensively on PT matters:
 * "[With] no-doubt metals on the far left of the table, and no-doubt non-metals on the far right ... the gap between the two extremes is bridged first by the poor [post-transition] metals, and then by the metalloids—which, perhaps by the same token, might collectively be renamed the "poor non-metals"."
 * That just leaves the transition metals and the unclassified nonmetals, both of which are bridging in nature, as observed by Atkins, and Welcher.
 * I won't fuss about this; if need be it'll be easy enough to revert the complementing sets.
 * That said, could you please consider the following:
 * The long history of the idea of parallels among the elements between e.g. active metals, less active metals, less active nonmetals and active nonmetals.
 * The cited article was published in a reliable, peer reviewed journal.
 * It's been cited seven times by other authors.
 * Each complementing set has been cited in other reliable sources.
 * An encyclopedia, as I understand the nature of WP, collects and presents what is understood to be factual information, as is the case here.
 * --- Sandbh (talk) 13:08, 22 October 2023 (UTC)
 * Well, I guess I wasn’t as clear as I could have been. I did not claim that the idea of pairing was novel, nor that the individual pairings were novel, but that the system as a whole is too novel to be prominently displayed. That others cite the article is interesting, but what I was looking for is some independent source that actually adopts this system. That was what I was hoping you could cite.
 * If I were writing this (which I am not), I would remove all of the discussion about pairings. This is, after all, primarily an article about nonmetals and not an article comparing them to metals, nor is it primarily an article about the subcategories, and it is certainly not an article about comparing the nonmetal subcategories to metal subcategories.
 * If I were determined to include something about this system of complementary subcategories (which I am not), I would add a single 2 sentence footnote somewhere in the introductory section about types. That is as far as I could go, but even that much seems undue to me.
 * YBG (talk) 23:50, 22 October 2023 (UTC)

Thanks YBG. I'll start by removing the image pairs. --- Sandbh (talk) 06:04, 23 October 2023 (UTC)

Could you kindly clarify what you meant by "the system as a whole ...[being] too novel to be prominently displayed"? At no time has the article displayed the system as a whole. Instead the parallels have been mentioned on a type by type basis.

While this is an article about nonmetals, many nonmetallic elements are said to have some metallic aspects; and many metallic elements have some nonmetallic aspects. Hence the comparison with metals is relevant and fruitful.

I've removed all the paired images except for the alkali metal-halogen image since this is Chemistry 101.

Please note that the text for each of the four types of nonmetals includes a reference to geographic analogies, which I've listed hereunder for convenience:


 * 1. "An analogy can be drawn between the noble gases and noble metals such as platinum and gold, as they share a similar reluctance to combine with other elements.[132] As a further analogy, xenon, in the +8 oxidation state, forms a pale yellow explosive oxide, XeO4, while osmium, another noble metal, forms a yellow, strongly oxidizing oxide,[133] OsO4. Additionally, there are parallels in the formulas of the oxyfluorides: XeO2F4 and OsO2F4, and XeO3F2 and OsO3F2.[134]"


 * 2. "The highly nonmetallic halogens in group 17 find their counterparts in the highly reactive alkali metals, such as sodium and potassium, in group 1.[149] Further, and much like the halogen nonmetals, most of the alkali metals are known to form –1 anions, a characteristic seldom observed among metals.[150]"


 * 3. "In the periodic table, to the left of the weakly nonmetallic metalloids are an indeterminate set of weakly metallic metals including tin, lead and bismuth,[153] sometimes referred to as post-transition metals.[154] Dingle explains the situation this way:
 * ... with "no-doubt" metals on the far left of the table, and no-doubt non-metals on the far right ... the gap between the two extremes is bridged first by the poor (post-transition) metals, and then by the metalloids—which, perhaps by the same token, might collectively be renamed the "poor non-metals".[155]"


 * 4. "There is a geographic analogy between the unclassified nonmetals and transition metals. The unclassified nonmetals are positioned between the strongly nonmetallic halogens on the right and the weakly nonmetallic metalloids on the left. Similarly, the transition metals occupy a region between the "virulent and violent" metals on the left side of the periodic table, and the "calm and contented" metals on the right. They effectively serve as a "transitional bridge" connecting these two regions.[184]"

Could you please advise me if you have any concerns about any of these paragraphs? --- Sandbh (talk) 07:09, 23 October 2023 (UTC)


 * I hope to get back to this later in the week. In the meantime perhaps @Double sharp would like to chime in. YBG (talk) 05:06, 24 October 2023 (UTC)

Pairs again
Earlier, you wrote:
 * "There are RS listed in the pictures that presumably show that a given author compared a specific nonmetal category with a specific metal category. But the sources are different for each one."

Earlier you wrote:
 * "I agree with your [YBG's] concern. Not only is each comparison cited to a different source, but the last one (unclassified to transition) is straightforwardly SYNTH (see ref. 158; neither source quoted actually spells out the connexion)."

My understanding is that it does not matter that the sources "are different for each one." The whole article is an encyclopedic compilation drawing on multiple sources. No single source captures all of the information set out in the article.

That said, the status of the image pairs is now that there are only two such pairs left: noble gas/noble metal; and halogen/alkali metal.

For the noble gases/noble metals image and paragraph I've added three further cites, and copy-edited the topic sentence for the paragraph.

For halogen/alkali metal, I earlier noted in this thread that I retained "the alkali metal-halogen image since this is Chemistry 101."

For the unclassified/transition metals paragraph I've further copy edited this and it now relies on a single source, rather than two separate sources.

Could your please review my responses to your concerns?

All going well, I'm aiming to relist nonmetal on Monday Nov 6, my time. thanks, --- Sandbh (talk) 06:38, 26 October 2023 (UTC)
 * Thanks for the response and edits; I'm happy with this now. Double sharp (talk) 09:06, 26 October 2023 (UTC)
 * I still find the comparisons overemphasized. Yes, people have made such comparisons. But they are too much in the weeds for an article summarizing the nonmetals.
 * Furthermore, placing the paired picture at the top of the NG (or halogen) section makes it seem as though that comparison is one of the most important things about the NGs (or halogens), which it most certainly is not. YBG (talk) 00:14, 27 October 2023 (UTC)

More thoughts
The sub-sub sections below mostly relate to the paired comparisons. I’ve added some stuff to the first paragraphs of the group 17 and 18 sections. Feel free to copy edit and add refs. (Thanks for the wiki link, @ Sandbh!)

Another detail … looking at the section headings above, I see several that include “FAC”. If someone has the time, it would ge good to append a number (FAC7 or FAC6 or whatever) before the sections get archived.

YBG (talk) 15:20, 27 October 2023 (UTC)


 * Thanks for listing items of concern in an organised manner; thanks for chiming in. --- Sandbh (talk) 05:34, 28 October 2023 (UTC)

NG/NM comparisons
YBG (talk) 06:24, 27 October 2023 (UTC)
 * I think my recent addition to the 1st paragraph on the section includes all that is needed about noble gases.
 * Do the sources for the 1st sentence in the comparison all say this comparison is “commonly drawn”? Or is “commonly” justified by the fact that three sources are listed?
 * The other two sentences of the comparison paragraph essentially compare a specific NG (Xe) and a specific NM (Os) - hardly significant enough to include in a general article about nonmetals. What’s left is just a statement that both categories are unreactive and that is adequately covered in the first paragraph. So I think this paragraph should be removed.
 * The comparison - with or without its paragraph - hardly deserves to be elevated in importance by using a paired illustration. Better to show just an example of a NG.


 * I do agree that the Xe-Os comparison could be removed. It is not really about the pairing, but is merely a case of a secondary relationship. Both elements have eight valence electrons over an inert core. In that sense it is like Cl-Mn (replace eight with seven), which does not fit the set of pairings too well. Double sharp (talk) 09:51, 27 October 2023 (UTC)
 * @Double sharp would you favor removing the first sentence also and not just the Xe-Os comparison? If so, do you think that the mention of gold and platinum should be added to the first paragraph if the section? YBG (talk) 15:30, 27 October 2023 (UTC)
 * Well, I just had the chance to look at Holleman & Wiberg. They compare noble gases to noble metals in the sense that one is group VIIIA, and the other is group VIIIB. It's part of a general comparison of main-group vs transition elements. So okay, there is a similarity, but for them it is not part of the full category-by-category set. Given that, I think I'd rather restrict it to what you suggested, indeed. Double sharp (talk) 16:02, 27 October 2023 (UTC)

In my opinion, incidentally, the mention of Xe intermetallics is misplaced here. It is not really about the noble gases, but rather it is about how metallicity, or lack thereof, inherently depends on pressure. So it should rather be part of a general discussion of what happens at high pressure, like we have that deep down. Yes, all elements eventually become metals, but there is sometimes weirdness along the way (Na first de-metallises before re-metallising). Double sharp (talk) 16:09, 27 October 2023 (UTC)
 * Thanks.
 * Recent 1st para. additions. With respect YBG, the recent additions to the first paragraphs of noble gases and halogen nonmetals have thrown out the structure of the sub-section. Comparative comments about each of the four types of nonmetal are made in the penultimate paragraph of each sub-section. For now, I've therefore reverted these edits.


 * "Commonly drawn" comparison? It's been drawn from as early as 1924, and continues to be drawn. While I haven't kept track of all the sources that I saw saying so, here are some of them:


 * The inclusion of the "noble gases" and the "noble metals" in the same periodic group 8, is therefore necessitated in the classification of the elements according to chemical properties and according to atomic structure. Mendeleef’s division of the “long periods” into even and odd series of over fifty years ago is today abundantly justified, and, though he later failed to appreciate the close relation between the “noble metals” and the “noble gases”…


 * — Main Smith JD 1924, Chemistry & Atomic Structure, Ernnest Benn Ltd., London, p. 78


 * The eighth vertical series is, however, remarkable in one aspect, in that its two natural families are the inert gases and the nine metals of the iron-platinum family. At first sight no two families of elements could appear more dissimilar, and yet popular phraseology has seized on one point of resemblance. For the former family is often spoken of as the "noble gases" ("Edelgasen"), whereas the platinum sub-family is generally referred to as the "noble metals," with the inclusion of gold from the currency group. In the opinion of hardworking chemists, the badge of nobility seems to be idleness and detachment from ordinary mundane matters. To this ideal the inert gases - the key elements thoroughly conform in all readily realisable circumstances. They are the "rois fainéants" of the chemical elements.


 * Under ordinary atmospheric conditions the noble metals display considerable chemical activity, although it is significant that this power of combination is manifested mainly in their co-ordination compounds, whence it may be deduced that a considerable part of the chemical affinity is supplied by electrons derived entirely from the associating addenda, which thus conduce to the stability of the resulting compounds.


 * At temperatures round about the melting point of lead most of the chemical energy of the platinum metals has already disappeared, and nearly all their compounds would have undergone thermal decomposition. If we could habitually live under such conditions we should experience very little reluctance in linking together in one group of inert elements the noble gases and the noble metals.


 * Moreover, some four members of the eighth metallic series give rise to volatile carbonyls in which the metallic atom appears not actively to contribute electrons, but to receive them passively from the various proportions of carbon monoxide, which go to form these remarkable metallic carbonyls (see pages 351).


 * Again it will be noted in the chapter on intermetallic compounds (page 336) that the Hume-Rothery rule giving simple ratios between the total number of valency electrons and total number of atoms in the molecule is valid for the alloys of iron, cobalt, nickel and palladium only if these metals contribute no electrons, or, in other words, have zero valency. Accordingly these passive attributes of the eighth family of metals afford some justification for their inclusion in the same periodic series as the inert gases.


 * — Morgan GT & Burtsall FH 1936, Inorganic Chemistry: A Survey of Modern Developments, W Heffer & Sons, Cambridge, p.256–257


 * With the exception of the 'noble gases', helium and its relatives, and the 'noble metals', gold and platinum, etc., we rarely find atoms existing as collections of single atoms.


 * Swanson MA 1959, Scientific Epistemologic Backgrounds of General Semantics: Lectures on Electro-colloidal Structures, Institute of General Semantics, Lakeville, CT, p. 29


 * ... Most chemists began to refer to the family as the noble gases' just as the rather unreactive and chemically aloof elements such as gold and platinum are referred to as the noble metals.
 * — Wood JH, Keenan CW & Bull WE 1968, Fundamentals of College Chemisty, 2nd ed., Harper International, New York


 * The gases are called the "noble" gases, in recognition of their low reactivity, which parallels that of the "noble" metals.


 * — Eastman RH 1970, General Chemistry: Experiment and Theory, Holt, Rinehart and Winston, New York, p. 455


 * Use of the terms transition or transitional elements … were originally applied solely to the group VIII triads (i.e., Fe-Co-Ni in period 4, Ru-Rh-Pd in group 5, and Os-lr-Pt in period 6) … These elements were very similar in their ... chemical properties ... and frequently resisted attack by common reagents (hence the name noble metal for the heavier members). When the rare or noble gases were later discovered, it was suggested that they too were transition elements, as they also bridged the gap between successive cycles of increasing maximum oxidation states. Indeed, they were considered to be more perfect examples of transitional species as the contrast between the elements at the end and beginning of successive periods (e.g., CI(VII) and K(I)) was much sharper than that between elements at the beginning and end of successive series (e.g., Mn(VII) and Cu(I)), and the transition occurred in these cases in one step rather than three. Finally, the noble gases appeared to be chemically inert, and thus represented truly "noble" elements, in contrast to the known reactivity of the so-called noble metals. This view of the group VIII triads as imperfect "noble gases" was also used by later writers on the periodic table and the observation that they should really be extended to transitional tetrads by incorporating Cu, Ag, and Au was first pointed out by Jorgensen.


 * — Jensen WB 1986, "Classification, symmetry, and the periodic table," Computers & Mathematics with Applications, vol. 12B (1−2), pp. 487−510 (496),


 * In place of the noble gases, the transition metal grouping has the noble metals.
 * — Wiberg N 2001, Inorganic Chemistry, Academic Press, San Diego, ISBN 978-0-12-352651-9


 * The start of noble gas chemistry in 1962 [occurred] with the help of a noble metal, platinum ... Interestingly, two nobles [noble metal and noble gas] make so strong [a] bond…that some of them reach the covalent limit. Gold is really a golden candidate to form a chemical bond with a noble gas atom due to relativistic contraction in radius and subsequent enhancement in electronegativity. Gold has the highest capability to form strong bond with noble gas atoms followed by copper and silver.


 * — Pan et al. 2019, "Noble-noble strong union: Gold at its best to make a bond with a noble gas atom", ChemistryOpen, February, pp. 173–187,


 * Some other considerations are:


 * The start of noble gas chemistry in 1962 occurred with the help of a noble metal, platinum, albeit no Pt-Xe bond was involved.
 * The field of noble gas-noble metal chemistry, which began in 1977, experienced a renaissance in 2000. While the focus of the linked article is to Cu, Ag and Au, there are mentions of other NM-NG compounds in the literature.


 * Xe-Os comparison. I included this example to add "color" and interest to the paragraph. Scerri mentions it in the 2007 and 2020 editions of his book, The Periodic Table: Its Story and Significance. He notes (2020, p. 411), "As Geoffrey Rayner Canham, a leading advocate of teaching inorganic chemistry in a qualitative manner, has written, the similarities shown far exceed any expectations on qualitative grounds."


 * As an aside it's interesting that a philospher such as Scerri, who's normally only concerned with high-level generalities, felt it worthwhile to mention this comparison.


 * Paired illustrations. I've replaced all these with single images.


 * Xe intermetallics. The relevance is that the topic sentence of the paragraph says:
 * About 1015 tonnes of noble gases are present in the Earth's atmosphere.[135]


 * The paragraph goes on to mention that, nevertheless > 90% of the expected amount of atomspheric Xe is depleted, and that the missing amount may be in the form of around 1013 tons of xenon, in the form of stable XeFe3 and XeNi3 intermetallic compounds. This mention further adds "color" and interest to the paragraph.
 * --- Sandbh (talk) 04:40, 29 October 2023 (UTC)
 * @Sandbh: Re my recent 1st paragraph additions: I am well aware that your penultimate paragraph included information about the category-pair comparisons. My recent additions included the only information from those paragraphs that IMO is needed. The remainder of the comparison paragraphs seems to violate FAC criteria 4 . YBG (talk) 05:58, 29 October 2023 (UTC)
 * The article is focused on the properties of the elements at ambient conditions, as mentioned at the top of the first section "Definition and applicable elements". Indeed, the classification of nonmetals into various categories, not to mention the question of which elements should be called nonmetals in the first place, depends on that. At pressures encountered in the Earth's mantle, xenon is a metallic conductor. So are oxygen, silicon, phosphorus, sulfur, germanium, arsenic, selenium, bromine, antimony, tellurium, and iodine. In my opinion, if that many have already gone missing, it is a clear sign that we are no longer in a situation where the old classification makes any sense. In my opinion, this fact really belongs under "Physical properties", as part of a general discussion of what happens at high pressure: elements that are metals in everyday life may stop being metals (Na), elements that are nonmetals may stop being nonmetals (Xe is a good example, since you have the text already), and eventually everything becomes a metal. After all, this situation is by no means limited to xenon. Double sharp (talk) 07:13, 31 October 2023 (UTC)
 * Thanks. Yes, that's right, the note at the top of the "Definition and applicable elements" section refers to ambient conditions. It adds a caveat however, and this says "unless otherwise mentioned." I've added a footnote and cite clarifying that Xe is expected to metallize at pressures in the Earth's core. I'm not aware of any other nonmetals "missing" to the extent of > 90% of their expected prevalence. All the type sub-sections mention where the elements occur, in their last paragraphs. I seem to recall trimming what happens to nonmetals under high pressure, and leaving that to the See also link, "Metallization pressure". Hopefully this will address your concerns.
 * --- Sandbh (talk) 04:13, 2 November 2023 (UTC)

Group 17/1 comparisons
YBG (talk) 06:24, 27 October 2023 (UTC)
 * I think my recent addition to the 1st paragraph includes all that is needed about alkali metals.
 * In keeping with the name halogen and the content of the first paragraph, I think a good illustration would have a picture with sodium metal on the left, chlorine gas on the right and a pile of table salt (or a salt shaker) in the center, with Na, NaCl, and Cl in the caption or even better in the pic itself.
 * The most salient parts of the comparison paragraph have been incorporated into the first paragraph. The only significant fact not in that paragraph is the common ability of group 1 and 17 to form -1 ions. I don’t think that is very significant in the context of a general article about nonmetals, and so I think that whole paragraph should be deleted.
 * I can agree with this, since −1 anions are not too characteristic of alkali metals even though they are mostly possible (for Li it is not even known yet, IIRC). Probably Au with actual aurides is a better comparison to the halogens, though off the top of my head I can't remember if it's been done in RS. Double sharp (talk) 16:05, 27 October 2023 (UTC)

Thanks.

I've previously addressed the 1st para. issue, and mentioned the removal of all the image pairs.

Regarding −1 alkalide anions, the context is:


 * 1) Nonmetals cannot be understood without appreciating metals i.e. the name "nonmetal" includes the term "metal". Please further see the two tables of comparative properties at the end of the article, both of which include a metals column.
 * 2) As noted, many nonmetallic elements have some metallic aspects; and many metallic elements (including e.g. Au) have some nonmetallic aspects. Hence the comparison with metals is relevant and fruitful.
 * 3) The synthesis of a crystalline salt of the sodium anion Na– was reported in 1974. It represented the second major overturning of conventional wisdom (Dye at al. 2006, p. 206), the first being the preparation of a noble gas compound in 1962. Since then further compounds (“alkalides”) containing anions of the other alkali metals (bar Li and Fr) as well as that of Ba(!), have been prepared.
 * 4) The relationship between the halogen nonmetals and alkali metals goes the other way: isolable salts containing diatomic or polyatomic cations of Cl, Br and I have been prepared (Wiberg 2001, pp. 419–421; Greenwood & Ernshaw 2002, p. 99).
 * 5) In the context of illustating 1 and 2 above, I feel the existence of −1 alkalide anions is noteworthy and interesting (noting this mention does not occur until the penultimate para. of the sub-section).
 * Dye et al. 2006, "Role of cation complexants in the synthesis of alkalides and electrides", Advances in Inorganic Chemistry, 205–231.

--- Sandbh (talk) 05:43, 29 October 2023 (UTC)


 * @Sandbh: Re my recent 1st paragraph additions: I am well aware that your penultimate paragraph included information about the category-pair comparisons. My recent additions included the only information from those paragraphs that IMO is needed. The remainder of the comparison paragraphs seems to violate FAC criteria 4 . YBG (talk) 05:57, 29 October 2023 (UTC)
 * I am not convinced that this is so relevant. Homopolycations aren't by any means restricted to the halogens. They are quite normal for the chalcogens too. It's been known since 1804 (Buchholz) that sulfur dissolves in oleum to give Sn2+ cations, and selenium and tellurium behave similarly (it's in the Greenwood and Earnshaw chapters on these elements). Salts of these chalcogen and halogen homopolycations are certainly less exotic than alkalides in another way; the counter-ion does not need special protection, as is normally needed for alkalides. That's why I'd think that Au is a better comparison to halogens, considering RbAu and CsAu. I'm obviously impressed by the immense skill that goes into preparing alkalides, but there we are talking about an odd sideline of a set of elements that seems to be as far from nonmetallic as possible. Is it really the most relevant possible comparison? I don't think so. I guess maybe one could compare these polycations with Zintl polyanions like Pb94−, but since I'm saying that off the top of my head, I'd like to see evidence from RS that any comparison you decide to put in is actually normal. Double sharp (talk) 08:26, 29 October 2023 (UTC)
 * Yes, I agree. I mentioned the halogen homopolycations in passing, in item #4 above. The context was that most metals have some nonmetal properties and vice versa e.g. most alkali metals can form –1 anions and most halogen nonmetals can form homopolycations. I suppose the halogen nonmetals could be expected to be among the unlikeliest of all to form cations (except for the NG). That was all.
 * Comment: Gold has some halogen-like properties.
 * Too, it is known as the +1 cation as are the alkali metals. The stoichiometry of Au(I) compounds often resembles that of alkali metal compounds, where the gold cation takes on a similar role to the alkali metal cation (e.g., Na+ or K+). Gold is able to form a –1 cation (more notably when combined with the heavier alkali metals), as are most of the alkali metals in alkalides. And Cs, which is in the same period as Au, has a pale golden tint.
 * --- Sandbh (talk) 06:57, 30 October 2023 (UTC)
 * If the point is "most metals have some nonmetal properties and vice versa", then sure, I agree. That is something worth saying in this article, and ties into what I said about the outliers. But if that is really all there is to it, then I am not convinced that it really supports the idea of a special relationship between halogens and alkali metals in terms of similarity (other than in terms of sheer contrast). Many metals are known in negative oxidation states, and basically all nonmetals but F and light noble gases (He, Ne, Ar) are known in positive oxidation states. If we forget about oxidation states and start talking about the actual charges (which are often very different), than even F can take a partial positive charge in AuF5·F2 (ref). Does that mean F is metal-like? Not in any very important way, I think. Double sharp (talk) 07:10, 30 October 2023 (UTC)
 * Thanks. I'm not sure the article sufficiently articulates the fact that "most metals have some nonmetal properties and vice versa". So that's something to look at later on.
 * There's a long history in the literature of a generalised pattern across the periodic table of highly active to less active (even noble) metals and a corresponding trend of less active (even noble) to highly active nonmetals.
 * It's in this context that the comparison between alkali metals and halogens forms part of Chemistry 101.
 * The similarities that come to mind are (i) relatively high reactivity; (ii) capacity for ionic bonding and salt formation; (iii) one set wants to give away an electron while the other wants to gain an electron, both in pursuit of a noble gas configuration; (iv) the two sets have a great attraction to one another. To which can be added the capacity of most of the alkali metals to form –1 anions, a finding that represented the second great upending of chemistry wisdom, the 1st being the discovery that xenon formed a compound.
 * Wiberg apparently thinks the prospect of a trifluro-cation F3+ is sufficiently interesting to make mention of it while noting it is thus far unknown (p. 421). There was a flurry of excitement in 2013 as to the apparently unprecedented preparation of an F atom with a positive charge on it. It was subsequently claimed by Christie et al. (2017), by my reading, that the fluorine atoms of interest only had a reduced negative charge.
 * Since F has such a high electronegativity then, yes, I feel that F with a positive rather than negative charge on it would represent noteworthy metal-like behaviour.
 * --- Sandbh (talk) 02:08, 31 October 2023 (UTC)
 * In response to your 05:57, 29 October 2023 (UTC) concerning recent 1st paragraph additions:
 * Thanks. I explained the relevance of −1 alkalide anions in my 5 numbered points above, especially points 1 and 2, and 5. What is it specifically about this one sentence (out of the 13 in the sub-section) that represents "unnecessary" detail, noting I left out mention of halogen cations? In considering your response, I feel that there are two other FAC criteria worth noting: 1a. well-written: its prose is engaging and of a professional standard; and 1b. comprehensive: it neglects no major facts or details and places the subject in context.
 * Re 1a., I've aimed to provide a well-written and engaging article rather than a cookie-cutter recycling of vanilla information. Engaging prose includes valuable context, and details that add depth, substance, and value to the content as I've sought to do in this case.
 * Re 1b., the (important) fact and context is that most metals have some nonmetal properties, and vice-versa, and that this is illustrated by the further parallel between halogen nonmetals and most alkali metals both being able to form -1 anions. The inclusion of this detail provides depth, and completeness to the article's coverage of nonmetals.
 * As well as these two extra FAC criteria, it is the lede where the general overview is provided. The main body of the article is then where the details are fleshed out, and the topic made more complete.
 * --- Sandbh (talk) 11:50, 30 October 2023 (UTC)
 * The -1 anion of alkali nonmetals is most certainly not a major fact or detail about halogen nonmetals, much less about nonmetals. It is an interesting factoid about alkali metals, and per 1b it is included in that article. IMO mentioning it here does nothing to make this article more engaging. YBG (talk) 15:09, 30 October 2023 (UTC)
 * Thanks. I feel that the –1 anion of alkali nonmetals is a major detail in the context of comparing halogen nonmetals with their alkali metal counterparts. It is a major detail in the context of nonmetal properties occurring in metals. Providing context around the subject matter can help reader engagement via being able to better understand and connect with the topic. While the –1 anion of alkali nonmetals would be no surprise to a chemist it may surprise the general reader relying on memories of high school chemistry. Engaging prose goes beyond presenting basic facts and information. Including such an intriguing or unexpected fact (for a general reader) can improve engagement by piquing their curiosity and encouraging them to continue reading. Taken out context it can be regarded as a factoid; it is more than that in terms of context and enagement.
 * --- Sandbh (talk) 01:51, 31 October 2023 (UTC)
 * @Sandbh, I’m not convinced. @Double sharp, what do you think? YBG (talk) 02:03, 31 October 2023 (UTC)
 * I've attempted to give multiple literature- and FAC criteria-based reasons why some of the relatively short content connected with pairing mentions should not be of concern. An elaboration of specific reasons for not being convinced would be helpful. Thanks. --- Sandbh (talk) 02:17, 31 October 2023 (UTC)
 * I disagree with your assumption that it is a major detail. As @Double sharp pointed out above, it is not terribly significant in establishing a relationship between group 1 and group 17. Even if it were a property shared only by these two groups (which apparently it is not), the fact that it is very common for group 17 and very rare for group 1 would make it quite a minor point of correspondence. It seems to me that if you were not so determined to include all these correspondences, you would easily recognize its insignificance. YBG (talk) 05:40, 31 October 2023 (UTC)
 * I agree with . Double sharp (talk) 07:32, 31 October 2023 (UTC)
 * Thank you.
 * I've changed the halogen nonmetals similarity paragraph to read as follows:
 * The halogens in group 17 find their counterparts in the alkali metals, such as sodium and potassium, in group 1. Correspondences between the two sets extend to high reactivity; the pursuit of a noble gas configuration; a common valence of one; the alkali metals being very similar to one another as are the halogens; and that hydrogen tends to be placed at the top of either the alkali metals (usually) or the halogens (less often).[147][n20]
 * Mention of –1 anions of alkali metals is now in a footnote.
 * Please bear in mind that my argument, now concerning a footnote, is not limited to criteria 1b on including major facts and details. I also presented arguments pursuant to criteria 1a.
 * On criteria 1b, the major idea is the alkali metal–halogen comparison. Alkalides are one of several supporting details such as high reactivity. The existence of –1 anions is a property shared by Na-K-Rb-Cs and F-Cl-Br-I. Across the periodic table there is no other comparison of this magnitude (AFAIK). Yes, in one sense, it is rare. That said it was the 2nd major overturning of chemistry wisdom. This makes it a big deal namely the idea that alkali metals could be present as –1 anions in compounds. Massey (2000, Main Group Chemistry, p. 113) wrote that this was an "extraordinary" development. Greenwood & Earnshaw wrote, "The chemistry of even the simplest elements has been considerably enriched during the past few years, sometimes by quite dramatic advances ... The chemistry of the alkali metals has a complexity that was undreamt of one or two decades ago ... Compounds of alkali metal anions and even electrides are known." (p. xix). That G&E felt –1 alkali metal anions were important enough to mention in the preface to their second edition is notable. As McCleverty & Meyer (2003) wrote, "The field of alkalides ... expanded tremendously in the 1980s and 1990s."
 * --- Sandbh (talk) 00:44, 3 November 2023 (UTC)
 * @Sandbh The -1 story is a big deal about alkali metals, but in the context of the subject of this article - nonmetals - it is only very tangentially related and not worth any mention at all. I begrudgingly accept it in a footnote. YBG (talk) 04:46, 3 November 2023 (UTC)

Quote boxes
YBG (talk) 06:24, 27 October 2023 (UTC)
 * The halogen nonmetal quote box would be a great quote IF the subject of this section were the comparison of groups 1&17 - or IF the subject were L-R PT trends. But it is neither. The subject of this section is halogen nonmetals as a type of nonmetal. Better to find another article for this quote.
 * Furthermore, having 5 elipses and one bracketed addition in a relatively short quote seems problematic. Just how much was left out?
 * Finally, when a section has a pic, a high bar must be reached to also have a quote box. That bar is far from met. Best to drop the quote box.


 * Done. --- Sandbh (talk) 05:45, 29 October 2023 (UTC)
 * Thank you. This is now resolved. YBG (talk) 05:47, 29 October 2023 (UTC)

Metalloid outliers
YBG (talk) 06:24, 27 October 2023 (UTC)
 * These outliers properly form a small part of the discussion of metalloids, which are but one of several types of nonmetals, and the types are just one aspect of the discussion of nonmetals. So outlier metalloids are just a small part of a small part of a small part of the subject of nonmetals. So while I think the outliers should be mentioned, five longish paragraphs and a picture seems WAY too much. Please collapse this section into a single sentence or at the very most a paragraph.
 * Since I'm the one who asked for some mention of the outliers, I'll add here that I'd be OK with YBG's proposal. Double sharp (talk) 10:02, 27 October 2023 (UTC)
 * Done. I've replaced the Outliers sub-sub section with a footnote, wikilinked to the Lists of metalloids article. --- Sandbh (talk) 11:18, 28 October 2023 (UTC)
 * Thank you. Thic concern is now resolved. YBG (talk) 16:55, 28 October 2023 (UTC)
 * I've boldly turned this into a short parenthesis (still less than a paragraph), because I think we ought to explain why the mention is relevant in a bit more detail. (It's basically because even elements on the metallic side of this line tend to have significant nonmetal-like properties.) Feel free to revert this (or edit it further) if you disagree. Double sharp (talk) 06:07, 29 October 2023 (UTC)
 * Works for me; I've trimmed it a bit. Sandbh (talk) 06:28, 29 October 2023 (UTC)

Unclassified nonmetals
Just wondering … would it be good to change to  or even ? In the introduction to Types, it seems it would read very well to say instead of  The addition of quotes (pardon their curliness here) might signify that this is descriptive not actual category name.

Thoughts? YBG (talk) 15:44, 27 October 2023 (UTC)


 * There's a footnote at the end of the unclassified nonmetals bullet point to which I've added a separate sentence that goes, "The descriptive phrase unclassified nonmetals is used here for convenience."


 * I hope that works. --- Sandbh (talk) 06:19, 29 October 2023 (UTC)
 * I don't know if that footnote is needed or not. My comment here about using quote marks was not a request for any specific action. Rather, I was offering a specific idea - the quote marks - as a possible solution to a problem we’ve wrestled with for years. My thought was, if this idea seems to help, please use it. But if this idea does not, feel free to disregard my post completely, no action is needed. So if you don’t think the footnote is needed or helpful, feel free to remove it. YBG (talk) 01:32, 30 October 2023 (UTC)
 * NFA required. --- Sandbh (talk) 07:04, 30 October 2023 (UTC)

Lead section & paragraph length

 * Hmm, it seems like the lead section now has a more organic definition of "nonmetal" (although I'll listen to Graham Beards' opinion on the matter). The only thing that comes to mind is that on my screen we have a lot of 2-3 lines long paragraphs; some merging may be warranted. Jo-Jo Eumerus (talk) 10:25, 23 October 2023 (UTC)
 * Tx JJE. The rule of thumb that I use is that no sentence should be longer than 30 words. If it is, then either shorten it or break into two. I was only able to find one sentence in the lede longer than 30 words, in the last para. I've now shortened it to 29 words. --- Sandbh (talk) 12:21, 23 October 2023 (UTC)
 * @Jo-Jo Eumerus, @Sandbh: I trust neither of you mind my moving this exchange into a separate section.
 * It appears to me that JJE is discussing paragraph length, but the reply is about sentence length.
 * I rather like the current lede paragraph lengths with line counts on my screen of (9,11,7,8,10) in portrait mode and (5,6,4,4,5) in landscape mode.
 * As to paragraphs in the rest of the article, the only really short ones are introducing an immediately following list or chart, which I think is appropriate. The longish ones of 10-12 or more lines don’t seem too long.
 * I’m not inclined to merge short paragraphs unless their topics are very similar. YBG (talk) 05:01, 24 October 2023 (UTC)
 * @Jo-Jo Eumerus Is your concern about paragraph lengths resolved? YBG (talk) 16:43, 19 December 2023 (UTC)
 * Aye, seems like. I'll probably perform a proper review on a FAC or a PR, though. Jo-Jo Eumerus (talk) 11:22, 20 December 2023 (UTC)

Single distinguishing properties table
As the table cells are advertised as being ordered by date, why not put the year at the beginning of each line, with a different hanging indent so that the year can function as a bullet without needing a bullet icon. YBG (talk) 02:29, 2 January 2024 (UTC)


 * Ok, I’ve tried this and am fairly satisfied with the result except for the fact that the years are proportionally spaced so not uniform in width. But I’m not wedded to it if anyone objects it can be reverted. YBG (talk) 04:40, 2 January 2024 (UTC)
 * Fixed with mono!! YBG (talk) 04:57, 2 January 2024 (UTC)
 * Very nice! --- Sandbh (talk) 07:19, 4 January 2024 (UTC)

Restating YBG’s questions
Restating and expanding my questions above in hopes of getting direct answers to each, especially from @Double sharp. YBG (talk) 18:57, 25 November 2023 (UTC)


 * I have added responses to each of my four questions by copying extracts from @Double sharp‘s response. Others - especially @Sandbh - are invited to add their own answers to these questions, or even to add additional questions. YBG (talk) 10:31, 7 December 2023 (UTC)
 * I have added section breaks as this discussion has grown longer than I had anticipated. YBG (talk) 06:11, 15 December 2023 (UTC)

YBG Q 1
(1) Is it helpful to mention the broad PT trend (L/metal-to-R/nonmetal) when discussing the 4-fold divisions of metals and of nonmetals (and their comparisons) ? YBG (talk) 18:57, 25 November 2023 (UTC)


 * Double sharp commented below YBG (talk) 10:20, 7 December 2023 (UTC)
 * I don't understand your question. Which "broad PT trend (L/metal-to-R/nonmetal)" are you referring to aside from metals on the L and nonmetals on the R? Please bear in mind that the context for the term "nonmetals" is "metals". It is helpful to mention metals in an article on nonmetals for contextual and educational purposes noting most readers are likely to be more familiar with metals. Sandbh (talk) 12:05, 13 December 2023 (UTC)

YBG Q 2
(2) How does (1977, p. 37, 112, 115, 145, 163, 182) present these metal-category-to-nonmetal-category comparisons? Do they reference one another (eg, ‘we see that these p-block metals correspond to metalloids in the same way that noble metals correspond to noble gasses’)? Or are they isolated comparisons without reference to one another? YBG (talk) 18:57, 25 November 2023 (UTC)


 * Double sharp commented below YBG (talk) 10:21, 7 December 2023 (UTC)
 * Parish ("The Metallic Elements") does not have metal-category-to-nonmetal-category comparisons.
 * Rather, he surveys the metals as s-block; 4f-elements; 5f-elements; 3d-metals; 4d- and 5d-metals (inc. a specific early mention of the nobles); and p-block metals:
 * s-block metals---"All the metals are highly reactive, the reactivity increasing with inreasing atomic number."
 * 4f-metals are "fairly reactive...In appearance and reactivity the metals resemble calcium and strontium."
 * 5f-metals are "highly reactive".
 * 3d-metals: "These are the familar metals and several of them are found in everday use...Many...are used for their corrosion resistance, which is chemically rater surprising, since all the metals are expected to very reactive...This apparent anomaly is due to the formation of a closely adherent layer of oxide which protects the underlying metal."
 * 4d- and 5d-metals are "least reactive of all"; noble metals are noted for "chemical inertness".
 * p-metals: "none particulary reactive".
 * Sandbh (talk) 11:26, 13 December 2023 (UTC)
 * Thank you for this listing. So it seems that this source does not in fact present metal-to-nonmetal-category comparisons.
 * (I'd argue that thallium is quite reactive. But that's not the point.) Double sharp (talk) 13:07, 13 December 2023 (UTC)
 * Yes, that's right. And it is accurate to observe that a broadly comparable range of types occurs among the metals, from highly reactive to less reactive (even noble). As mentioned earlier in the thread, there is a long history in the literature of noting complementing sets of metals and nonmetals. Sandbh (talk) 02:22, 14 December 2023 (UTC)
 * And yet you cannot seem to provide evidence outside your own work for it. The point is, the source you have provided does not appear to support the point of the paragraph without some WP:SYNTH. Double sharp (talk) 02:29, 14 December 2023 (UTC)


 * Double sharp (talk) 02:30, 14 December 2023 (UTC)
 * So, the point of the paragraph is that a broadly comparable range of types occurs among the metals, from highly reactive to less reactive (even noble).


 * I think I would rely on the following citations:


 * 1. "There are groups of elements that have similar properties, including highly reactive metals, less reactive metals, highly reactive nonmetals (such as chlorine, fluorine, and oxygen), and some almost completely nonreactive gases (such as helium and neon)."
 * --- American Association for the Advancement of Science, 1993, Benchmarks for Science Literacy, Oxford University Press, New York, p. 78


 * 2. "The elements change from active metals, to less active metals, to metalloids, to moderately active nonmetals, to very active nonmetals, and to a noble gas."
 * --- Welcher SH 2001, High marks: Regents Chemistry Made Easy, 2nd ed., High Marks Made Easy, New York, p. 3-32


 * 3. "Those [elements] classified as metallic range from the highly reactive sodium and barium to the noble metals, such as gold and platinum. The nonmetals…encompass…the aggressive, highly-oxidizing fluorine and the unreactive gases such as helium."
 * --- Overton et al. 2018, Inorganic Chemistry, 7th ed., Oxford University Press, Oxford, preface


 * Each citation encapsulates the spectrum of reactivity/activity and the transition from metallic to nonmetallic elements across the periodic table. --- Sandbh (talk) 12:44, 14 December 2023 (UTC)
 * I’m coming up for air here. The question raises in this subsection is @Double sharp summarized your answer by saying Parish, to which @Sandbh replied, . So the question posed in this subsection has been answered. My apologies for not realizing this earlier. YBG (talk) 14:46, 16 December 2023 (UTC)

YBG Q 3
(3) Other than @Sandbh’s own work, how much RS support exists for this 4-fold division of metals? YBG (talk) 18:57, 25 November 2023 (UTC)


 * Double sharp commented below YBG (talk) 10:23, 7 December 2023 (UTC)
 * The "broadly comparable range of types among the metals" referred to in the paragraph is based on the s-, f-, d- and p-block metals, a "division" which is well-established and widely supported in the literature.
 * The s- and f-block metals are comparable in reactivity; the noble metals are a well-recognised subset of the d-block metals.
 * The reactivity of metals is a frequent and important topic in the literature due to the central role that metals play in various chemical processes and in industrial applications:
 * their reactivity is crucial in various industrial processes, such as metallurgy, catalysis, and the production of alloys, batteries, and electronic components;
 * they are central to electrochemistry, including battery technology and electroplating; understanding and developing these technologies relies on reactivity;
 * the reactivity of metals is important in environmental chemistry, particularly in the context of pollution and remediation; e.g. the mobility and toxicity of heavy metals in the environment are closely related to their chemical reactivity;
 * understanding the reactivity of metals helps in illustrating and applying periodic trends, such as ionization energy and electronegativity;^ it's also important in theoretical and computational chemistry for predicting reactivity and designing new materials.
 * ^ The accompanying table showing the distribution of EN values nicely brings out the progression from less electronegative to more electronegative among the nonmetals. A similar progression occurs for the types of metals.
 * Holleman & Wiberg write, "In place of the noble gases, the transition metal grouping has the noble metals." Indeed. Sandbh (talk) 02:07, 14 December 2023 (UTC)
 * @Sandbh The 4-fold division of metals I’m asking about is the one in you mention in the article’s paragraph and in the EN table: (1) s+f block metals, (2) non-noble d-block metals, (3) p-block metals, and (4) noble d-block metals. My question is, how much RS literature is there for this division? A brief answer would be very appreciated either (a) by giving a few RS refs (besides your own) that divide the metals into these four top-level divisions, or else (b) by stating that you can find none. Thank you. YBG (talk) 03:05, 15 December 2023 (UTC)
 * Scott & Kanda (1962, p. 385), The Nature of Atoms and Molecules: A General Chemistry, divide the metals into 1. very active (Groups 1 and 2, Al-Sc-Y-Ln-An); 2. ferrous, including Fe and metals frequently used with it (Ti-Ni; Nb, Mo, Ta, W) 3. noble; and 4. soft (very active excluded).
 * King (1995, p. 289), Inorganic Chemistry of the Main Group Elements, discusses in one chapter, the alkali and alkaline earthmetals, and in another the Ln and An on the grounds that Ln chemistry is predominately the chemistry of highly electropostive metals in the +3 state, just as the chemistry of the alkali metals and alkaline metals is the chemistry of highly electropositive metals in the +1 and +2 states.
 * Atkins (1995, pp. 24–25), The Periodic Kingdom: A Journey Into The Land Of The Chemical Elements, writes, "Between the “virulent and violent” metals on the left of the periodic table, and the “calm and contented” metals to the right are the transition metals, which form “a transitional bridge between the two” extremes.
 * NB: The paragraph in question is not about "top-level divisions". It instead refers to a broadly comparable range of types of metals, including the noble metals as a subset of the transition metals. Sandbh (talk) 02:09, 16 December 2023 (UTC)
 * None of these citations use the categorization of the paragraph in question, so it would seem better not to reference these four divisions. It seems this paragraph is not so much about these four (RS unsupported) divisions (top level or otherwise), but rather about the “broad range”. This point, I believe, would be better made without the clutter of listing these four categories and the numerous examples. Why not simply note that the wide range of reactivity of nonmetals is comparable to the wide range of metals, and then list examples from the extremes? YBG (talk) 03:14, 16 December 2023 (UTC)
 * Thanks. First, I'd like to add Holtzclaw et al. (1988), General Chemistry, 8th ed. who refer to "active metals", "TM metals", and "post-TM". In their TM chapter they write, "The heavier elements... Ru, Os, Rh, Ir, Pd, and Pt are sometimes called the platinum metals. These elements and Au are particularly nonreactive." For the Ln/REE and An they write (pp. 802–803) that the former are active metals and that the latter have properties similar to the rare earths (apart from showing a much wider range of oxidation numbers). I'll respond more specifically to your suggestion in my next post. Sandbh (talk) 03:24, 16 December 2023 (UTC)
 * The paragraph uses s-, f-, d- and p- nomenclature due to, as you've seen, (i) the different ways the literature refers to different kinds of metals in the same vicinities of the PT e.g. the 18 different names for the metals to the right of the TM; (ii) confusion about which elements are TM, as opposed to d-block; and (iii) related confusion about where the PTM start, as opposed to p-block metals. The "broad" qualifier is intended to accomodate the fact that there will be, from source to source, variations at the boundaries. I'm not quite sure what you mean by the 2nd part of your question. You may mean e.g. "Na to Ni, and Au", as "highly reactive to less reactive (even noble)". I feel this would devalue the paragraph, in terms of contextual understanding, educational value, enhancing interest, and a balanced perspective, making it less comprehensive and less informative. In a roughly 8,350 word article on nonmetals a brief mention (~200 words) of the comparable situation on the other side of the fence, would seem to be not unreasonble especially since "non"-metals only have meaning in the context of their opposites. The FAC criteria likewise mention comprehensiveness and neglecting no major facts or details and placing the subject in context. --- Sandbh (talk) 11:41, 16 December 2023 (UTC)
 * The question posed in this subsection was To this, it seems, the closest example @Sandbh has given is Holtzclaw, which seems to be a (3+1)-fold subdivision. To be fair, Sandbh sometimes expresses his typology of metals in a 3+1 manner. So the answer to this subsection is “a little bit of support, but certainly not widespread”. YBG (talk) 20:54, 16 December 2023 (UTC)
 * I recall Cox (2004), Inorganic Chemistry, BIOS Scientific, who refers to: (i) Pre-transition metals (p. 186); (ii) Transition metals (p. 207); (iii) Post-transition metals (p. 186); (iv) Ln and An (Chapter I, pp. 245–252). Separately, he mentions the platinum metals as exacerbating a trend in reduced reactivity (p. 209). The Ln are described as electropositive and reactive elements (p. 246). The early An are described as being similar to TM (p. 249), noting the "more reactive" nature of the early TM (p. 268); the later An are are described as being more similar to the Ln (p. 250). --- Sandbh (talk) 05:53, 18 December 2023 (UTC)
 * This is not an example of your 4-fold or (3+1)-fold typology. It would be a different entry on a List of alternative metal classes. YBG (talk) 14:23, 18 December 2023 (UTC)
 * Eh? Cox refers to the pre-transition metals (≈ s-block metals); the transition metals (≈ d-block metals); the post-transition metals (≈ p-block metals); the Ln/An (≈ f-block metals); and the platinum metals (≈ noble metals). The paragraph in question refers to the s- and f-block metals; the transition metals; the p-metals, and the noble metals as a subset of the transition metals. --- Sandbh (talk) 03:48, 20 December 2023 (UTC)
 * Your typology gathers d-block and f-block metals together, which it appears Cox does not. YBG (talk) 05:40, 20 December 2023 (UTC)
 * Oops, I meant to say “s-block and f-block metals”; but Sandbh correctly understood me. YBG (talk) 19:01, 30 December 2023 (UTC)
 * Thanks. 1. Pls recall the long history in chemistry of a comparable range of types of metals and nonmetals, such as active metals, less active metals, less active non-metals, active non-metals, and inert gases. 2. Similarly, the article mentions a broadly comparable range of types as highly to fairly reactive s- and f-block metals; transition metals, of high to low reactivity; p-block metals, none particularly reactive; and a subset of the TM (inc. Pt and sometimes Au) called "noble metals" (or platinum metals) due to their inactive nature. 3. Similarities between the s- and f-block metals are well-established in the literature. A. Wiberg (2001, Inorganic Chemistry, pp. 1703, 1720) writes, "The Ln resemble their neighbours to the left in the periodic system, the alkali and alkaline earths... The An are fairly reactive elements, similar in some respects to their still more electropositive neighbors, the AM and AEM." B. Scott & Kanda (1962, p. 385) referred to the "very active metals" as Groups 1 and 2, Al-Sc-Y-Ln-An. C. Hamm (1969, Fundamental Concepts of Chemistry, p. 490) refers to the "most active metals" as "those in groups IA and IIA (and the lanthanides and actinides ...)." D. Siekierski & Burgess (2002, Concise Chemistry of the Elements, pp. 70, 77, 169) note the high electropositivity of the Group 1 and 2 metals (except Be) and the high electropositivity of the Ln and An. --- Sandbh (talk) 12:37, 20 December 2023 (UTC)
 * Similarities are great, but do not make a typology. I do not object to saying that metals, like nonmetals, exhibit a range from very reactive to very unreactive. I object to the way it is presented as a 4-fold (or 3+1-fold) typology if metals. I believe this violates WP:SYNTH; I’m confident @Double sharp agrees), but you believe it is a reasonable use of RS. There is no evidence that any other WP editor agrees with you. I know you don’t believe that your opinion trumps everyone else on WP. If you want to demonstrate a spirit of collaboration, please try revising these paragraphs to remove these SYNTH concerns. Or agree to let someone else have a go. YBG (talk) 21:04, 20 December 2023 (UTC)
 * Thanks. WP:SYNTH exists to prevent original research (OR), not synthesis per se. There's no OR in saying there's a comparable range of types among the metals, given the long history in the literature of a recognized pattern of reactivities across both metals and nonmetals e.g. active metals, less active metals, less active non-metals, active non-metals, and inert gases. Such quotes suggest a recognized framework within the field for comparing and contrasting different types of elements based on reactivity. Some relevent citaions are attached. Ergo, there's no OR. On the spirit of collaboration, I feel I've gone to considerable lengths to accommodate your concerns. In the same spirit, I hope you can also extend similar understanding, flexibility and accommodation to my perspectives."
 * 1. "There are groups of elements that have similar properties, including highly reactive metals, less reactive metals, highly reactive nonmetals (such as chlorine, fluorine, and oxygen), and some almost completely nonreactive gases (such as helium and neon)."
 * --- American Association for the Advancement of Science, 1993, Benchmarks for Science Literacy, Oxford University Press, New York, p. 78
 * 2. "The elements change from active metals, to less active metals, to metalloids, to moderately active nonmetals, to very active nonmetals, and to a noble gas."
 * --- Welcher SH 2001, High marks: Regents Chemistry Made Easy, 2nd ed., High Marks Made Easy, New York, p. 3-32
 * 3. "Those [elements] classified as metallic range from the highly reactive sodium and barium to the noble metals, such as gold and platinum. The nonmetals…encompass…the aggressive, highly-oxidizing fluorine and the unreactive gases such as helium."
 * --- Overton et al. 2018, Inorganic Chemistry, 7th ed., Oxford University Press, Oxford, preface
 * Each citation encapsulates the spectrum of reactivity/activity and the comparable transition among metallic to nonmetallic elements across the periodic table. --- Sandbh (talk) 12:44, 14 December 2023 (UTC) Sandbh (talk) 05:00, 21 December 2023 (UTC)
 * @Sandbh: Having recently re-read WP:SYNTH, I am not convinced. IMO, each of these sources use terms like “active” descriptively, not as a typology. I’ve said before, I am willing to consider using these terms descriptively in this article, but I am not willing to concede that these refs support your 4-fold typology. Nevertheless, if you can convince @Double sharp or any other editor that accentuating this 4-fold typology of metals does not violate WP:UNDUE much less WP:SYNTH, I will reconsider my position. Furthermore, I believe your recent introduction of the phrase “long history” also violates WP:SYNTH, unless one of your sources actually makes such a comment. YBG (talk) 05:57, 21 December 2023 (UTC)
 * Thanks. 1. I've edited the para. to remove mention of types. It's now a descriptive para. Ditto image notes. Failing this, could you pls read WP:NOTSYNTH, esp. sections 4, 6, 11, 12, 13 and 20.
 * 2. The 4-fold typology is not "my" typology; it's a simple observation of the range of reactivity "types" (with types used in an informal, descriptive sense) mentioned in the literature. 3. Regarding WP:UNDUE, I've already explained that a more specific mention of metals on a taxonomic basis is less common. Accordingly, the one paragraph is limited to 2.5% of the article. 4. The phrase "long history" is a reflection of the fact that the four cited sources span the period 1947 to 2018; I could change this to "recurring" if that would do. --- Sandbh (talk) 10:38, 21 December 2023 (UTC)

Further discussion re refining edits

 * @Sandbh thanks for your edit, which went a long way to focusing on description rather that typology. I built on this as I further streamlined the paragraph, with an edit summary explains the removal of three quotations. I note in passing that WP:SYNTH is a section in WP:NOR, an enwiki policy, whereas WP:NOTSYNTH is an essay not fully vetted by the community. But let’s not go down the wikilawyering path. After all, I do kinda like your 4-fold typology for all its quirks. I’m just not sure it merits mention here. As to the inclusion of this paragraph and the EN chart accompanying it, my idea is to improve it as best you and I can, then if by its merits it convinces @Double sharp or some other editor that it merits inclusion, well and good. But if not, we should bid the paragraph and chart a fond farewell. YBG (talk) 13:48, 22 December 2023 (UTC)
 * At first glance, your edits look quite good :) Am going to look closer now and maybe do some more ce. --- Sandbh (talk) 05:20, 26 December 2023 (UTC)
 * Copy edit done. I added mention of the periodc table context. The two quotations you left are VG and nicely illustrative. I know you attempted to address Al by joining the d- and p-blocks together but there is no support in the literature for this. I had to adjust the reactivities and blocks because it is not s/f- high; d- moderate; p- low; and noble least. There is instead some overlap between the blocks. I removed the EN table because, in light of your good work, there seems to be no longer a need for it. How do you feel now about the paragraph? Thanks --- Sandbh (talk) 06:36, 26 December 2023 (UTC)
 * @Sandbh I’ve made some further tweaks.
 * Added level 3 section head, primarily to make editing easier. If it’s not useful to the reader, please don’t delete until early January or so.
 * Rephrased “In a PT context” - (Where else does one find elements?) to mention the general trend.
 * Rephrased “Highly to fairly reactive”, “High to low”. These are arbitrary levels of reactivity. There’s no need for such artificial precision. “Very reactive” and “less reactive” are accurate descriptions. Both d and p are less reactive than s and f. But maybe it would be better to start by saying s/f are “most reactive”?
 * Dropped unhelpful example of relatively unknown scandium.
 * I’m still uncertain why we need a note about aluminium, especially if all we say is that p/d are less reactive than s/f. But I’ve left it in for now.
 * YBG (talk) 07:30, 27 December 2023 (UTC)
 * Thanks.
 * The level 3 section head is fine, for now.
 * OK
 * The phrasings such as “Highly to fairly reactive” etc are from Parish (1977); they aren't arbitrary. Parish is careful with his expressions. d is not necessarily less than s/f. The d-metals include metals having high to low reactivities.
 * I gave Sc as an example of a highly reactive d-metal; Fe is moderately so; Ni is fairly laid back. Hence these three metals cover the high to low reactivity span. That said, I've replaced Sc with Ti.
 * The note for Al reflects that fact that descriptions of Al vary. So, e.g. Rayner-Canham treats it as a "chemically weak metal"; whereas Whitten and Davis (1996, p. 853) write, “[It] is quite reactive, but a thin, transparent film of Al2O3 forms etc."
 * I've ce'd the para. accordingly. I replaced U with Ce, as a better example of "fairly reactive". --- Sandbh (talk) 07:23, 28 December 2023 (UTC)
 * Thank you @Sandbh.
 * 3. My objection to the X-to-Y descriptions is not lack of support, but imposing wordiness on readers.
 * 4. Giving examples of various levels of reactivity is beautiful, but only helps readers familiar with Ti/Fe/Ni reactivity. Examples should anchor our prose in what is familiar to the reader.
 * 5. The Al footnote, then, is necessitated by the p-block generalization. A better solution is to avoid that generalization.
 * 6. Replacing well-known U with less-known Ce is unhelpful to our readers.
 * I think the source of our disconnect is that we are crafting our sentences to answer different questions. You ask:
 * How reactive are s/f? Highly to fairly
 * How reactive is d? High to low
 * How reactive is p? Not particularly (footnote Al)
 * Oh, and by the way, noble metals.
 * I avoid the X-to-Y wordiness and the Al footnote by asking these questions:
 * Where are the most reactive metals found? s/f
 * Where are less reactive metals? d/p
 * Where are the least reactive metals? d-block island
 * Both approaches seek to describe the L-to-R trend. Do you think I’ve accurately described our different approaches? YBG (talk) 18:04, 28 December 2023 (UTC)
 * @Sandbh: I have reworded the paragraph accordingly; comments are welcome. I’m particularly interested in whether my previous post accurately describes the difference in our approaches. YBG (talk) 19:54, 28 December 2023 (UTC)
 * Thanks YBG.
 * 3. Agree wordiness is to be avoided; clarity of expression is the goal.
 * 4. Agree anchoring prose in what's familar, where practical. As a technical article, familiarity for all readers won't always be possible.
 * 5. Footnotes provide helpful additional information. That said, the Al footnote is no longer needed given the new wording.
 * 6. Replaced U with Ce, since U is highly reactive (per Parish) whereas Ce is only fairly reactive. Older readers would likely be familar with Ce due to its presence in lighter flints. I've replaced Ce with Nd given the latter's wide use in magnets.
 * Your description of our approaches is fairly good, noting my concerns about mushing d/p.
 * Broadly picking up your structure, I've edited the paragraph, further reducing the word count, and restoring text-source integrity. --- Sandbh (talk) 00:58, 29 December 2023 (UTC)
 * @Sandbh, is there no way to avoid the clumsiness of “highly to fairly reactive metals” and “metals of high to low reactivity”? Yes, I get it, these expressions are used in the sources, but we are not quoting directly, we are paraphrasing, so there is no need to mimic clumsy wording. YBG (talk) 05:12, 29 December 2023 (UTC)
 * Thanks. The issues are that the s-block and 5f metals are highly reactive, with the exception of Be, which is not quite so reactive; and the 4f metals are "fairly" reactive,  So we have to accomodate Be/4f, hence "highly to fairly". The other issue is (a) some overlap between the s-metals and the early d-metals i.e. some of the earlier d-metals are highly reactive; and (b) some of the non-noble d-metals have low reactivity (and some are in-between). I've edited the paragraph so that it now refers to s/f as "highly to fairly"; d as "varying reactivity", encompassing high to low; and p as less reactive. I feel this better accomodates the distinctions, including the overlapping nature of the d-metals. Sandbh (talk) 01:48, 30 December 2023 (UTC)
 * @Sandbh: I note that you have reverted to describing blocks in terms of reactivity, which brings the boundary fuzziness to the forefront, making description less succinct. I plan to make another stab at describing reactivity in terms of location. Now that I understand the situation better, I think I’ll do a better job of it. YBG (talk) 18:55, 30 December 2023 (UTC)
 * Yes, you did a much better job, including accomodating boundary fuzziness. I've made some minor adjustments. The mention of Mg is particularly nice and I learnt something new about its adherant and protective oxide coating. Thanks. --- Sandbh (talk) 01:05, 31 December 2023 (UTC)

Sources gathered from elsewhere on this TP
Additional source #1 moved from here in § YBG Q 4 to here in § YBG Q 3 by YBG (talk) 07:06, 20 December 2023 (UTC)
 * Cue one more reference: Steele (1966), The Chemistry of the Metallic Elements, most recently cited in 2020. He divides the metals into: alkali (strongly basic, p. 32), alkaline earth (fairly strongly basic, p. 49); inner transition, with the Ln closely resembling the alkaline earths, and the An similar in many ways to the Ln (p. 122); transition; and later b-Subgroup metals of weak electropositive character (p. 67). The noble metals are mentioned for their unreactivity (p. 19). --- Sandbh (talk) 07:59, 19 December 2023 (UTC)

Additional source #2 moved from here in § YBG Q 4 to here in § YBG Q 3 by YBG (talk) 07:06, 20 December 2023 (UTC)
 * PS: Barrett & Malati (1998, Fundamentals of Inorganic Chemistry: An Introductory Text for Degree Course Studies, Horwood Publishing) refer to s-block metals (most reactive, p. 159); f-block metals (highly electropositive, p. 275); d-block metals (p. 257); p-block metals (p. 199) and noble metals (p. 273). — Preceding unsigned comment added by Sandbh (talk • contribs) 10:13, 19 December 2023 (UTC)

Additional source #3 moved from here in § YBG Q 4 to here in § YBG Q 3 by YBG (talk) 07:06, 20 December 2023 (UTC)
 * PS re RS. Gifford et al. (2011, p. 153) in The Kingfisher Science Encyclopedia, 3rd ed., divide the PT into the s-block and f-block elements, noting that (but for H) the s-block and first row f-block are all very reactive metals (the 2nd row f-elements are radioactive many being synthetic); the d-block elements, which are metals much less reactive than the s-block metals; and the p-block elements, of which Sn and Pb are "typical p-block metals", being softer than d-block metals and less reactive. They refer to gold as a "noble metal" (p. 146) and platinum as examples of the least reactive metals (p. 183). Sandbh (talk) 23:33, 18 December 2023 (UTC)

YBG Q 4
(4) Would this article about nonmetals be better without a reference to this 4-fold division of metals? YBG (talk) 18:57, 25 November 2023 (UTC)


 * Double sharp commented below …. YBG (talk) 10:26, 7 December 2023 (UTC)
 * No, quite the contrary, it would be worse, in my view.
 * Since the article discusses the types of nonmetals  a brief mention of the range of metal types is beneficial, for the following reasons:
 * Contextual understanding: Mentioning the types of metals, from highly reactive to noble, provides context and a fuller picture of the periodic table. Sandbh (talk) 02:40, 14 December 2023 (UTC)
 * The goal of this article is providing context and a fuller picture of nonmetals, not of the PT as a whole. A comment about the broad range of metals can provide that context without referencing a rather uncommon typology of metals. YBG (talk) 06:07, 18 December 2023 (UTC)
 * As noted, appreciating "non"-metals or "not" metals requires at least some understanding of metals and the periodic table e.g. metals on the left but for H; nonmetals on the right. That's far short of providing a picture of the PT as a whole, for which whole books have been written. As noted, the paragraph takes up ~2.4% of the article, and the concept of s-block metals, f-block metals, d-block metals; and the p-block, where metals meet the nonmetals is well established. We may consider Spice (1964) Chemical Binding and Structure, Pergamon Press, who was cited as recently as 2019. He divides the metals into highly electopositive; inner transition ("electropositive"); transition ("fairly electropositive"); and B-subgroup ("not very electropositive"). He mentions gold and the platinum metals in the context of their structures. Sandbh (talk) 00:31, 19 December 2023 (UTC)
 * Educational value: For readers who are more familiar with the properties of metals, comparing them to nonmetals can provide a more intuitive understanding of the latter. Drawing parallels between the types of metals and nonmetals helps in reinforcing the concept that, while metals and nonmetals differ in their properties, they can be appreciated though the same organisational paradigm. Sandbh (talk) 02:40, 14 December 2023 (UTC)
 * Perhaps metals and nonmetals could be appreciated through the same organisational paradigm, but using an organizational paradigm for metals with thin RS support gives an inaccurate impression and so is educationally detrimental. YBG (talk) 06:07, 18 December 2023 (UTC)
 * Tx. First an explanation. In general chemistry (GC), the group-by-group (GBG) treatment for the main groups is common. The f-block metals tend to get short shrift, with most of the focus on similarities among the Ln. The TM tend to be addressed by looking mainly at the 3d metals. The other metals :) are located in G13, 14, 15, 16, and 17. The chemistry of the G13 metals is usually done well. The chemistry of the metals in G14, 15, 16 and 17 tends to get mushed into the GC of the Groups in question. But this is not a GC article, and a GBG treatment is not the major focus.
 * An article focused on nonmetals and their taxonomy, including contextual information about their namesake counterparts, is not about GC. Ergo, the fact that such a more specific mention of metals on a taxonomic basis is less common does not mean it conveys an inaccurate impression nor is it educationally detrimental.
 * The educational value is further enhanced by a consistent approach and the careful positioning of the paragraph in question i.e. after the four types of nonmetals are mentioned but before their type-by-type exposition.
 * Cue one more reference: ... Sandbh 07:59, 19 December 2023 (UTC)
 * Additional source #1 moved from here in § YBG Q 4 to here in § YBG Q 3 by YBG (talk) 07:06, 20 December 2023 (UTC)
 * Enhancing interest: For some readers, understanding that there is a broad and comparable range in both metals and nonmetals might pique their interest and encourage them to explore more about these elements and their properties. Sandbh (talk) 02:40, 14 December 2023 (UTC)
 * Yes,, but this does not require introducing a typology of metals, much less one thin RS support. YBG (talk) 06:07, 18 December 2023 (UTC)
 * Yes, I suspect many things can an be argued away on the basis that they are not necessarily required. OTOH, a one paragraph mention adds depth, context, and a structured framework for comparison, enhancing educational value and reader engagement. Which is a lot about what an FAC article would presumably be aiming to achieve. Sandbh (talk) 10:09, 19 December 2023 (UTC)
 * PS: ... Sandbh 10:13, 19 December 2023 (UTC)
 * Additional source #2 moved from here in § YBG Q 4 to here in § YBG Q 3 by YBG (talk) 07:06, 20 December 2023 (UTC)
 * Balanced perspective: Including information about metals ensures a more balanced perspective, preventing the article from being too focused on just one part of the periodic table. It highlights the interconnectedness of different elements in chemistry. Sandbh (talk) 02:40, 14 December 2023 (UTC)
 * I’m not sure at what point an article about nonmetals becomes too focused on … umm … nonmetals. But as we seek a balanced perspective, we should not introduce details about metals with thin RS support that are not even mentioned in the metal article. YBG (talk) 06:07, 18 December 2023 (UTC)
 * Tx. The article becomes too focused on nonmetals when it forgets that appreciating "non"-metals (or "not" metals) requires at least some understanding of metals, and the periodic table (e.g. metals on the left; nonmetals on the right). While nonmetals are in some senses the opposite of metals, they share some aspects, e.g. the classic example of uber reactive alkali metals and  uber reactive halogens. Inclusion of such content fosters a balanced perspective. Re thin RS support, and as noted, the paragraph takes up ~2.4% of the article. For the metal article, I'm the lead editor. It's not comparable as it hasn't yet had an FAC-standard upgrade.
 * PS re RS. ... Sandbh 23:33, 18 December 2023 (UTC)
 * Additional source #3 moved from here in § YBG Q 4 to here in § YBG Q 3 by YBG (talk) 07:06, 20 December 2023 (UTC)
 * Overall, a brief mention of the types of metals in contrast to nonmetals enriches the article, making it more comprehensive and informative. Sandbh (talk) 02:40, 14 December 2023 (UTC)
 * In summary, I don’t think this particular typology of metals belongs in the nonmetal article. Perhaps it could find a home in a List of alternative metal classes - patterned after List of alternative nonmetal classes (not List of alternative metal artists, LOL). YBG (talk) 06:07, 18 December 2023 (UTC)
 * Tx. I've acknowledged and addressed your concerns including in terms of relevance/FA criteria. I've noted this article is not primarily about general chemistry but is instead focused on nonmetals and a taxonomy of same. I've set out how the article is enriched via several benefits. These include: context; well-established notions of s-, f-, d-, p- and noble metals or their effective equivalents; increased understanding and enagagement; a consistent organisational framework; careful positioning of the paragraph; depth; educational value; comprehensiveness, and a balanced perspective. Along the way I added four more references. I'll close the summary with another  reference.
 * Wei et al. (2023) examine the uses of metals in the electrocatalysis of CO2, with a view to addressing present-day energy and environmental crises. They parse the metals as follows: s-block metals; p-block metals; d-block metals (including a discussion of noble metals); and f-block metals. --- Sandbh (talk) 23:29, 19 December 2023 (UTC)
 * @Sandbh, I would like to respond to each of your points in turn. Would it be ok if I duplicated tour signature after each point and then answered each in a separate thread? YBG (talk) 01:29, 17 December 2023 (UTC)
 * That'd be absolutely OK. Sandbh (talk) 03:38, 18 December 2023 (UTC)
 * Thanks. I've done so. YBG (talk) 03:43, 18 December 2023 (UTC)
 * @Sandbh Would it be ok if I moved your additional references to the end of the Q3 section so they’re all together? I’ll add “moved to” and “moved from” notes. YBG (talk) 16:38, 19 December 2023 (UTC)
 * Yes, of course; please proceed. --- Sandbh (talk) 23:30, 19 December 2023 (UTC)
 * That'd be absolutely OK. Sandbh (talk) 03:38, 18 December 2023 (UTC)
 * Thanks. I've done so. YBG (talk) 03:43, 18 December 2023 (UTC)
 * @Sandbh Would it be ok if I moved your additional references to the end of the Q3 section so they’re all together? I’ll add “moved to” and “moved from” notes. YBG (talk) 16:38, 19 December 2023 (UTC)
 * Yes, of course; please proceed. --- Sandbh (talk) 23:30, 19 December 2023 (UTC)

More re YBG Qs
(5) (Editors are invited to replace this placeholder text with additional questions.)

Thank you! YBG (talk) 18:57, 25 November 2023 (UTC)
 * I don't have Parish, so can't answer (2). My view for (3) is "not much": for example, when Holleman & Wiberg talk about noble gases vs. noble metals, it's not so much about contrasting nonmetals with metals, but about contrasting main groups with transition groups (i.e. it's really about secondary relationship and Xe and Os having eight valence electrons). Thus I would say yes to (4), which perhaps makes (1) moot. Double sharp (talk) 04:32, 27 November 2023 (UTC)
 * @Double sharp: I presume that means you favor removing the entire last paragraph, the one just before (correct me if I’m wrong). What about the EN vs. Type chart that comes just before it? (It’s not clear whether it is just illustrating the paragraph re the 4-fold division of metals, or if it is also illustrating the comments in the previous paragraph about electronegativity.) Should the chart be removed completely? Modified to just include nonmetals (and metalloids)? Retained as is with both metals and nonmetals? And if any is to be kept, should it be converted to a wiki table? YBG (talk) 06:09, 27 November 2023 (UTC)
 * Personally, I would favour removing it all, because of my answer to (3). It seems to be referenced to a repository of chemical data, so the interpretation inherent in the tabulation is likely OR.
 * At most, a reasonable place for the metal-nonmetal trend to be briefly mentioned would be in the section for metalloids, because the continuity of this trend is why authors differ on which elements to call metalloids. Double sharp (talk) 13:32, 27 November 2023 (UTC)
 * Ok, I’ll remove the graphic and the paragraph. YBG (talk) 13:52, 27 November 2023 (UTC)
 * Removal edit reverted. Since this was not agreed by me, nor was I asked to express my opinion, it remains open to discussion --- Sandbh (talk) 03:12, 2 December 2023 (UTC)
 * @Sandbh: Thank you for responding. I welcome your input; I had expected to hear from you when i pinged you by reference. I look forward to your responses to my four questions (1), (2), (3) and (4). I think it would help keep the discussion on target if you answered each directly following the question itself. If you think there are other important questions, you are welcome to add (5) etc. Thank you. YBG (talk) 06:34, 2 December 2023 (UTC)

I think this long but fruitful discussion has now reached its natural end; I can’t think of any significant changes needed to this section now. YBG (talk)< — Preceding undated comment added 03:34, 7 January 2024 (UTC) YBG (talk) 03:25, 12 January 2024 (UTC)

Astatine and Polonium
Isn't astatine a metalloid (sometimes considered) ? I've even seen polonium considered a metalloid. 2603:6000:8740:54B1:98C0:1879:4C99:365D (talk) 02:08, 30 August 2023 (UTC)


 * Both have been classified as metalloids by some authors, though the consensus isn't as clear as for the main ones (B, Si, Ge, As, Sb, Te). See lists of metalloids for a more in-depth analysis. Complex / Rational  11:15, 30 August 2023 (UTC)
 * Thanks. I've usually seen astatine regarded as a nonmetal or metalloid; occasionally as a metal. Polonium I've seen regarded as a metalloid, though usually a metal. 2600:1008:B18F:94F7:495F:FB73:818D:885A (talk) 17:53, 31 August 2023 (UTC)

Astatine has an unusual history in that when it was first syntheized it was considered to be a metal. Experimental evidence and recent theory suggests it may indeed be a metal. In-between it seems to have suffered from its association with the halogens. Ergo it must be a nonmetal, ignoring trends of increased metallicity going down the group. Non-relativitic calcuations pointed to it being a semiconductor and hence a metalloid candidate. Relativity points to it being a post-transition metal.

Polonium is soluble in acids, forming the rose-coloured Po2+ cation and displacing hydrogen: Po + 2 H+ → Po2+ + H2. It has no band gap and no semiconducting allotropes. Hence it's a metal. Sandbh (talk) 05:46, 19 September 2023 (UTC)
 * Polonium is further down in the electrochemical series than hydrogen, and appears in about the same place as ruthenium. Hence, a caveat must be added: polonium often gets oxidised by media that electrochemically should not oxidise it, because of radiolytic decay products. Double sharp (talk) 15:37, 12 January 2024 (UTC)