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Reclassifying the nonmetals

Reclassifying the nonmetals is the title of an original post here at WT:ELEMENTS by Sandbh, 12 March 2017. Long and large discussions followed, now in the archives. Below is the current status. -DePiep (talk) 22:30, 27 July 2017 (UTC)

• Original post and discussion (part 1/n): /Archive 27
• (part 2/n): /Archive 28, continuation

-DePiep (talk) 12:45, 13 August 2017 (UTC)

• (part 3/n): /Archive 29, naming the group of eleven: - YBG (talk) 05:42, 19 August 2017 (UTC)

Reclassifying the nonmetals: Another continuation

(as this seems to be a natural break, a section head was inserted by YBG (talk) 19:03, 19 July 2017 (UTC)

I changed my mind for around a half-dozen reasons.

Properties table. I drafted a summary table of 21 properties of the metalloids, the other nonmetals, and oxygen and the halogen nonmetals—the table can be found here—and was pleasantly surprised by the contrast between the three classes in terms of at least the headland properties of oxidising power, ionic v covalent bonding, ionisation energy, electron affinity, and electronegativity. Please note that the table is a work in progress, and that the supporting citations are missing.

Muddying the waters/consensus in the literature. Looking at the table I can now see that moving oxygen into an other metals category would "muddy the waters" as much as would moving nitrogen into the same category as oxygen and the halogens. Placing oxygen and nitrogen in different categories accords with consensus in the literature that oxygen and the halogen nonmetals are chemically the strongest of the nonmetals.

Category names. Being consistent with the literature-based distinction between chemically weaker and chemically stronger nonmetals is more important than category names. In that light I'd be happy to call the other nonmetals "other nonmetals" rather than "intermediate nonmetals".

The nonmetal article. The properties table I referred to earlier provides a superb foundation to draft a revised nonmetal article around. The end result would be richer than the current version of the article and would, in my view, have FAC potential.

Electronegativity values. I finally understood where Double sharp was coming from on the nitrogen question. He was starting with the high electronegativity value of nitrogen, which would place it among oxygen and the halogen nonmetals. I was starting with nitrogen's ionisation energy, electron affinity, electronegativity, oxidising power, and covalent chemistry which, when considered together, would place it among the other nonmetals. Neither approach is wrong.

After I drafted the above reasons, Double sharp and I were able to agree offline that, since metallic and nonmetallic character are composites of several properties, and given the high level of abstraction we are attempting to cater for in our colour categories, nitrogen is more suitably placed among the other nonmetals.

We further agreed that in our periodic table article, in the electronegativity section, it would be good to include a periodic table showing the elements colour-coded (using a different colour scheme) by electronegativity, with black dividing lines between the periodic table categories.

Subject to your views I intend to draft a revised nonmetal article for your consideration and, if this is acceptable, to seek consensus at Template talk: Periodic table for the two new colour category names i.e. "other nonmetals", and "corrosive nonmetals".

I'm not fussed if the metalloids remain as a third super category rather than a nonmetal category, and would welcome any further thoughts about this in light of the "Parsing the nonmetals" essay in my sandbox, which has matured a lot since I last brought it your attention.

Thank you to:

• Double sharp for making me think so hard and at such length;
• Parcly Taxel for your category name ideas, especially oxidative and reductive nonmetals, and seeking to move things forward;
• YBG for your category name ideas and for suggesting that Double sharp and I might be able to reach an agreement;
• R8R for challenging me on the notion of a dichotomy among the chemically active nonmetals and reminding me about the corrosive nonmetals;
• DePiep for reminding me of Mendeleev's wisdom.

--- Sandbh (talk) 14:20, 19 July 2017 (UTC)

Summary of where we are

To summarize where we are:

• Retain "Metalloids" as a supercategory parallel with metal and nonmetal
• There seem to be three distinct possibilities for categorizing nonmetals
  1. Status quo: noble gasses, diatomic NM, polyatomic NM
  2. Proposed trichotomy: noble gasses, 6 corrosive NM, 5 other NM
  3. Proposed dichotomy: noble gasses, 11 chemically active NM
• The primary (only?) argument for the status quo seems to be a lack of consensus on an alternative

Previous trichotomy: NG NMs / Other NMs / Halogens	He,Ne,Ar,Kr,Xe,Rn,Og	C,P,S,Se	H,N	O	F,Cl,Br,I	At	B,Si,Ge,As,Sb,Te
Current trichotomy: Monatomic NMs / Polyatomic NMs / Diatomic NMs	He,Ne,Ar,Kr,Xe,Rn,Og	C,P,S,Se	H,N	O	F,Cl,Br,I	At	B,Si,Ge,As,Sb,Te
Proposed trichotomy: NG NMs / Other NMs / Corrosive NMs	He,Ne,Ar,Kr,Xe,Rn,Og	C,P,S,Se	H,N	O	F,Cl,Br,I	At	B,Si,Ge,As,Sb,Te
Proposed dichotomy: NG NMs / Chemically active NMs	He,Ne,Ar,Kr,Xe,Rn,Og	C,P,S,Se	H,N	O	F,Cl,Br,I	At	B,Si,Ge,As,Sb,Te

YBG (talk) 19:03, 19 July 2017 (UTC)

Further discussion

YBG

I believe that Sandbh has provided clear reasoning for calling O,F,Cl,Br,I "corrosive nonmetals" and including clear reasoning for why O should be included in this set and why N should not be included. He has demonstrated quite well that this set of elements is much more coherent chemically than the current diatomic nonmetals. Specifically, he maintains that this coherence makes sense from two different but related points of view (1) the literature tends to treat these elements together and (2) the chemical properties of this set of elements are similar.

All of this argues indisputably for adding a new corrosive nonmetals sub-section to nonmetal § Categories, and I believe this can and should be done right now without waiting for this discussion to reach a conclusion.

There remains the question of whether this category should be used in our PT-coloring scheme or not.

Sandbh says Being consistent with the literature-based distinction between chemically weaker and chemically stronger nonmetals is more important than category names.

I agree that our PT-coloring categories should be consistent with literature-based distinctions. But there are many literature-based distinctions, far more than we could hope to include in our coloring scheme. The question for us as editors and as a wikiproject is Which of the literature-based distinctions should we include in our PT coloring scheme? - specifically should this distinction be included in our PT-coloring scheme.

We have these choices, listed in the order that I believe Sandbh currently prefers:

• The proposed trichotomy: include the distinction between corrosive nonmetals and the rest of the non-noble nonmetals in our coloring scheme or
• The proposed dichotomy: categorize all 11 chemically active nonmetals together or
• The status quo: retain the status quo. [yuck]

My preference would be (1) proposed dichotomy (2) proposed trichotomy (3) status quo. My reasons, in order of importance to me, are

• I find the category name "Other nonmetals" to be fundamentally flawed, and
• the distinction between "corrosive" and "other" nonmetals, while great, is much less than the distinction between noble gasses and the chemically active nonmetals, and
• we have too many categories as it is. (I believe we should aim for The Magical Number Seven, Plus or Minus Two.)

I could be persuaded to accept the proposed trichotomy provided Double sharp both agree on it and we come up with a better name than "Other nonmetals". "Weak nonmetals" is marginally acceptable, but certainly if this categorization is notable, we should be able to come up with a better category name.

(Note: There is a difference between (a) the set corrosive nonmetals is a significant and notable set of elements and (b) the categorization of NNNM into corrosive and other nonmetals is a significant and notable classification. The latter is a MUCH stronger statement. YBG (talk) 00:17, 20 July 2017 (UTC)

YBG: Points 1 and 2 (ONM a flawed name, distinction vs. cohesion) are strong, then you killed it by point 3: "seven" it should be. Nice in human perceptions, not relevant in the PT. If seven is the number, Nature would have dealt us a magic square PT with 49 elements. -DePiep (talk) 21:49, 20 July 2017 (UTC)

IMHO, things like groups and periods are almost always presented to us indisputably and are subject to interpretation only at the ragged edges. That is to say, at the ragged edges we might have a vigorous discussion about the constitution of group 3, but this is not the norm. I cannot come up with any conceivable circumstance in which two people would disagree about which elements are in group 2 or group 12, right? But with these categories, there really is a lot of room for editorial input. Should we stick to just three top-level categories? Should the chemically active nonmetals be one category or two? Should the lanthanides and actinides be two categories or one? Should the alkali metals and alkaline earth metals be two categories or one? Should metalloids be a separate supercategory or a subcategory of nonmetals? Knowledgeable people of good will might very easily disagree about these questions about categorization. My point with the 7±2 reference is that one important consideration is that we should keep our readers in mind. To the extent that it is possible, we should aim to have the number of categories small enough so that the reader is not overwhelmed and can keep them in mind easily. YBG (talk) 23:10, 20 July 2017 (UTC)

I think you can go over the magic number, but only if you have some sort of hierarchy to it, so that each individual subset of the categories is not so large. Combined with an "unknown properties" lack of category, I think the ten we have now is a reasonably good number. (By the way, your mentioning of groups 2 and 12 as an indisputable case is kind of funny; in the early 20th century quite a few periodic tables moved Be and Mg to be on top of Zn, and indeed they fit rather well there thanks to their small size. The argument against that is to some extent almost as dicey as that for group 3.) Double sharp (talk) 23:27, 20 July 2017 (UTC)

Yea, hierarchy and "chunking" helps you go over 7±2; my concern is that when viewing our PT, one does not see a hierarchy but rather 10 different categories that pretty much stand parallel to each other. The legend does display the hierarchy, but I don't think it is enough to help people "chunk".

As to 2 and 12, yea, I hadn't thought about that. I suppose there was some IUPAC subcommittee, a predecessor to Scerri's group 3 group, that finalized the group membership, or maybe it was just professional consensus (and without the benefit of talk pages). But I have a hard time thinking about the IUPAC setting up a committee that would make a final decision about category definitions and boundaries. But on second thought, maybe they would, and then DePiep would be right in that we may just be part of the foundational work of PT categories: 'Our' PT Categorisation ... has a high degree of quality for the RL scientific world ... so that it isn't too much of a stretch to say that we are claiming and defining ... the word 'category'. YBG (talk) 07:10, 21 July 2017 (UTC)

Re helping people to chunk, the legend helps but there is no immediately accompanying guide to the legend, that explains how it works and summarises the nature of the elements in each category. The closest we get to doing this doesn't happen until another two images and eleven paragraphs later. Maybe a guide could be done as a drop down to the big PT. Sandbh (talk) 10:28, 21 July 2017 (UTC)

(outdent)

I have changed my opinion and now favor three categories of nonmetals: (1) the nobel gases He, Ne, Ar, Kr, Xe, Rn, Og; (2) H, C, N, P, S, Se and (3) O,F,Cl,Br,I. The main thing that convinced me was to recognize that because the nonmetals are so much more diverse than the metals, it makes sense that the nonmetal categories would have fewer members on average than do the metal categories. But my support for changing from the diatomic/polyatomic status quo is contingent on eliminating the category name "other nonmetals". @Sandbh, Double sharp, and Parcly Taxel: It seems all four of us now agree that this categorization of the nonmetals is the best. Might we also be able to agree on the best names for the two NNNM categories? The only two alternatives that have been mentioned, AFAIK, are

• (a) NNNM = "corrosive nonmetals" + "other nonmetals"

  I am strongly opposed to using the term "other nonmetals" for reasons that have been oft stated before and which I will repeat here if so requested. Further, I suspect that even those who don't share the strength of my opinion would still prefer to avoid that term.

• (b) NNNM = "oxidative nonmetals" + "reductive nonmetals"

  This was proposed by Parcly Taxel and AFAIK, there has been nothing said against this. Unless something better appears, I also support it.

I believe that further discussion of the category names should be either in #The other test or in a brand new sub-section. YBG (talk) 07:19, 26 August 2017 (UTC)

Parcly Taxel

Come to think of it, I'm now convinced by Sandbh's arguments that the distinction between H/C/N/P/S/Se and O/F/Cl/Br/I is significant, and thus I now have more support for the proposed trichotomy. Remember how I argued that a viable category needed to have a representative element? Well, considering these categories as the oxidative and reductive nonmetals (and these are definitely the best names we have now), we have representatives:

• Hydrogen represents the reductive nonmetals and reduction
• Oxygen represents the oxidative nonmetals and oxidation

These are the two elements that figure most prominently in redox reactions. Just as we have oxidising agent and reducing agent, so we can have oxidative nonmetal and reductive nonmetal. The overall nonmetal article would then emphasise this division first, linking to the two smaller categories' pages in its section, before moving on to lesser categorisations.

Electrochemical categories: NG NMs / Reductive NMs / Oxidative NMs

He,Ne,Ar,Kr,Xe,Rn,Og

H,C,N,P,S,Se

O,F,Cl,Br,I

B,Si,Ge,As,Sb,Te,At

But then there is a far more compelling argument in favour of the proposed trichotomy: our periodic table then becomes one solidly based on electrochemistry. All the metals are reducing, with the alkali and alkaline earth metals particularly so; metalloids are slightly more oxidising, and the proposed trichotomy illustrates very clearly the rest of the transition to oxidising tendencies. The status quo is dead, since its polyatomic/diatomic classification has nothing to do with electrons. Likewise, leaving the Group of Eleven as just the chemically active nonmetals is not going far enough in this regard – we can be more detailed than that. Parcly Taxel 02:07, 20 July 2017 (UTC)

I hereby invite others to comment on Parcly Taxel's proposal to use the terms oxidative nonmetals and reductive nonmetals. I don't know enough to voice an opinion other than my extreme revulsion to other nonmetals. YBG (talk) 16:30, 15 August 2017 (UTC)

sure. What is trichotomy, why is that now a classifying principle (why as in: 5 mths later while this page does not introduce it), and I do not trust yet the 'needs [!] example element' claim then disrupting the logic using that invented need. For all you still here: did you known Sandbh did not sign his OP? I invaded the archive to post-fix this. DePiep (talk) 17:36, 15 August 2017 (UTC)

wikt:Trichotomy means dividing things into three classes, but that has nothing to do with my question, which related specifically to Parcly Taxel's proposal to use the terms "oxidative nonmetals" and "reductive nonmetals" for the categories that Sandbh has been calling "corrosive nonmetals" and "other nonmetals". YBG (talk) 23:34, 15 August 2017 (UTC)

DePiep

re Sandbh "I changed my mind for around a half-dozen reasons". To be clear, what this is about: now you oppose a dichotome division ('Chemically active NMs', 'Noble gases') which you earlier on liked? (or should I just read Archive 27? Any reading advice?)

re article "periodic table showing the elements colour-coded (using a different colour scheme) by electronegativity": can be done always, irrespective of this nonmetallictivity topic outcome. The electronegativity color scheme should be different from the category color scheme to prevent any confusion. We already have single-property colored PTs like {{Periodic table (crystal structure)}} and {{Periodic table (electronegativity by Pauling scale)}}. IOW: electronegativity is off-topic (nice, and helpful).

DORG re "to seek consensus at Template talk:Periodic table for the two new colour category names i.e. "other nonmetals", and "corrosive nonmetals"." Please no! This category issue is so abstract and comprehensive that it should be at our king talkpage WT:ELEMENTS. I think 'our' PT Categorisation by now has a high degree of quality for the RL scientific world and it might become leading (for starters, claiming and defining claiming the word 'category'). If the organisation of a big long talk is an issue, we should tackle that in other ways — here. (I even doubt if element properties is just a periodic table topic; also Talk:nonmetal could be thought of).

By now, Sandbh, could you give us an outline of the articles for the new categories? What will corrosive nonmetal, other nonmetal be like? They can't be redirects like today's diatomic nonmetal. I can imagine an article NNNM that describes these two, especially since the comparing is major. -DePiep (talk) 21:32, 20 July 2017 (UTC)

Also: a single article NNNM can nicely solve that awkward "Other ..." naming issue. -DePiep (talk) 21:51, 20 July 2017 (UTC)

@DePiep: Just to clarify, I still support the dichotomy (chemically active) more. It's just that I found the trichotomy (oxidative/reductive) arguments good enough that they should be covered in more detail in a chemically active nonmetals article (the NNNM article you mentioned). Parcly Taxel 00:20, 21 July 2017 (UTC)

@DePiep: Yes, I currently no longer support a division into chemically active nonmetals and noble gases.

I never really liked the proposed division into chemically active nonmetals and noble gases because, to me, this would hide knowledge and make it harder to see the symmetry of the periodic table. The care we take with categorising the metals deserves to be carried over into the nonmetals.

In the end I went along with the active-noble division as the lesser of two evils.

On why I then changed my mind, I can advise you to read the Parsing the nonmetals mini-essay in my sandbox and especially the summary table comparing the metalloids, the other nonmetals, and oxygen and the halogens, across 21 properties. I changed my mind largely as a result of compiling that table.

Yes, to be clear about the electronegativity table, this would show the elements colour coded by EN, and there would be black dividing lines, somewhat like the periodic table in the heavy metal article, showing our ten periodic table categories. The purpose of doing so is to be able to compare the pattern in electronegativity with the progression in metallic or electrochemical character represented by our colour categories. I expect that, for example, N, O, F, and Cl would be in the EN > 3 category, and that Au, C, S, Se, Br and iodine would in the EN 2.5--3 category.

On seeking consensus at Template talk: Periodic table I recall we sought consensus outside of our project page for the polydi categories essentially for the reason that we are a small project. I think we also recognised the need to seek consensus outside of our project for similar changes in the future.

For articles there would be our nonmetal article, and our noble gas article. Beyond that, I won't know until I redraft the nonmetal article. Certainly, if the nonmetal article got too long, we could have separate articles for the rest of the nonmetal categories.

On the "other nonmetal" category name issue, I'm still thinking about this.

PS: What does DORG stand for? Sandbh (talk) 05:06, 21 July 2017 (UTC)

I've started drafting a rewrite of the nonmetal article to see how it would look. Sandbh (talk) 07:13, 22 July 2017 (UTC)

Thanks. Visually combining category and electronegativity in a PT looks great (informative). I introduced DORG "Organisation of the discussion (not content)" to indicate a non-content paragraph, trying to separate organisation from content in the discussion. -DePiep (talk) 11:05, 28 July 2017 (UTC)

• Note: if we create new any new categories (for those NNNMs), new colors are required too. Good key-coloring is: "different definition = different color". We cannot reuse the green and yellow. When a changes nears, I'll suggest new colors (will still be some green and yellow, these are good). -DePiep (talk) 20:57, 12 August 2017 (UTC)

The other test

Anything better than "other nonmetal" needs to work better than these descriptions:

Location	Description
Other/Corrosive                      — Sandbh (talk) 13:52, 21 July 2017 (UTC)
Group 16	Oxygen is a corrosive nonmetal, sulfur and selenium are other nonmetals, tellurium is a metalloid, and polonium is a post-transition metal.
Group 15	Nitrogen and phosphorous are other nonmetals, arsenic and antimony are metalloids, and bismuth is a post-transition metal.
Period 2 (p block)	Boron is a metalloid, carbon and nitrogen are other nonmetals, oxygen and fluorine are corrosive nonmetals, and neon is a noble gas.
Reductive/Oxidative                      — YBG (talk) 21:57, 24 August 2017 (UTC)
Group 16	Oxygen is an oxidative nonmetal, sulfur and selenium are reductive nonmetals, tellurium is a metalloid, and polonium is a post-transition metal.
Group 15	Nitrogen and phosphorous are reductive nonmetals, arsenic and antimony are metalloids, and bismuth is a post-transition metal.
Period 2 (p block)	Boron is a metalloid, carbon and nitrogen are reductive nonmetals, oxygen and fluorine are oxidative nonmetals, and neon is a noble gas.
Heterogenic/Corrosive                      — YBG (talk) 06:49, 27 August 2017 (UTC)
Group 16	Oxygen is a corrosive nonmetal, sulfur and selenium are heterogenic nonmetals, tellurium is a metalloid, and polonium is a post-transition metal.
Group 15	Nitrogen and phosphorous are heterogenic nonmetals, arsenic and antimony are metalloids, and bismuth is a post-transition metal.
Period 2 (p block)	Boron is a metalloid, carbon and nitrogen are heterogenic nonmetals, oxygen and fluorine are corrosive nonmetals, and neon is a noble gas.
Heterogeneous/Corrosive                      — YBG (talk) 06:49, 27 August 2017 (UTC)
Group 16	Oxygen is a corrosive nonmetal, sulfur and selenium are heterogeneous nonmetals, tellurium is a metalloid, and polonium is a post-transition metal.
Group 15	Nitrogen and phosphorous are heterogeneous nonmetals, arsenic and antimony are metalloids, and bismuth is a post-transition metal.
Period 2 (p block)	Boron is a metalloid, carbon and nitrogen are heterogeneous nonmetals, oxygen and fluorine are corrosive nonmetals, and neon is a noble gas.
Foundation/Corrosive                      — Sandbh (talk) 06:47, 31 August 2017 (UTC) (UTC)
Group 16	Oxygen is a corrosive nonmetal, sulfur and selenium are foundation nonmetals, tellurium is a metalloid, and polonium is a post-transition metal.
Group 15	Nitrogen and phosphorous are foundation nonmetals, arsenic and antimony are metalloids, and bismuth is a post-transition metal.
Period 2 (p block)	Boron is a metalloid, carbon and nitrogen are foundation nonmetals, oxygen and fluorine are corrosive nonmetals, and neon is a noble gas.
Formative/Corrosive                      — Sandbh (talk) 06:47, 31 August 2017 (UTC) (UTC)
Group 16	Oxygen is a corrosive nonmetal, sulfur and selenium are formative nonmetals, tellurium is a metalloid, and polonium is a post-transition metal.
Group 15	Nitrogen and phosphorous are formative nonmetals, arsenic and antimony are metalloids, and bismuth is a post-transition metal.
Period 2 (p block)	Boron is a metalloid, carbon and nitrogen are formative nonmetals, oxygen and fluorine are corrosive nonmetals, and neon is a noble gas.

• Original chart (Other/Corrosive): Sandbh (talk) 13:52, 21 July 2017 (UTC)
• Reductive/Oxidative added: YBG (talk) 21:57, 24 August 2017 (UTC)
• Heterogen[ic/eous]/Corrosive added: YBG (talk) 06:49, 27 August 2017 (UTC)
• Foundation/Corrosive added: Sandbh (talk) 06:47, 31 August 2017 (UTC)
• Formative/Corrosive added: Sandbh (talk) 06:47, 31 August 2017 (UTC)

Update

I’ve drafted a revised nonmetal article, here, using the categories other nonmetal, corrosive nonmetal, and noble gas. It includes biographical sketches of all the nonmetals as per, if memory serves, a suggestion by Parcly Taxel. I’ve referred to the metalloids for comparative purposes.

The draft needs polishing in some areas. The PT images need to be updated. There are a couple of red letter notes in the article I need to address.I need to add more supporting citations. I said I’d include a PT coloured by electronegativity, with dividing lines between our ten categories, but haven’t done this yet.

I’m posting this FYI or comments, given the draft has now got to a state where I’m more or less happy with it. Sandbh (talk) 07:21, 18 August 2017 (UTC)

A wonderful reading it is! It nicely sails the seas of categorisations, smartly uses metalloids all along for perspective, describes other schemes as well. I enjoyed it. -DePiep (talk) 10:07, 27 August 2017 (UTC)

• About the table in #Alternative_categories. Wouldn't it be helpful and illustrative to add the basic Other/Corrosive/Noble set in top, for comparision? BTW, it is the first table-form listing of these in the article. -DePiep (talk) 10:27, 27 August 2017 (UTC)
• About the order and introduction of the categories: "The seven metalloids are", "There are six other nonmetals", "There are five corrosive nonmetals namely", "Six nonmetals are categorised as noble gases". We know why it is this way, but the "other nonmetals" position now reads illogic (as a leftover class, expected at the end of a listing). Is there a solution? Italicise as words like "called other nonmetals"? -DePiep (talk) 11:13, 27 August 2017 (UTC)

Thank you DiPiep for your kind words. I especially liked "nicely sails the seas of categorisations" and I appreciate your comment about the metalloids. I'm glad you enjoyed it.

• Yes, that's a good idea.
• I think the solution is to come up with a better name than "other nonmetals". I posted something to my talk page about this a day or so ago, to see if could get some in-principle agreement before posting something more formal here. Sandbh (talk) 12:42, 27 August 2017 (UTC)

YGB, Double sharp, and I agree with Parcly Taxel's well-put proposal to have the following categories of nonmetal: reductive nonmetal (H, C, N, P, S, Se), oxidative nonmetal (O, F, Cl, Br, I), and noble gas. This trichotomy, if it gets up, would replace the current trichotomy of diatomic nonmetal, polyatomic nonmetal, and noble gas.

Parcly Taxel's proposal is here. The discussion that YBG, Double Sharp, and I had that got us to this point is here. I'll make some adjustments to the draft in my sandbox and then post a RfC.

— Preceding unsigned comment added by Sandbh (talk • contribs) 05:58, 1 September 2017 (UTC)

As a part of that RfC, it would be good to summarize the rationale for this categorization change and briefly list some of the significant alternatives considered, including the status quo and the previous status quo for context. Such a summary should be self-contained so that it can be evaluated without having to refer off-page to prior discussions. YBG (talk) 17:29, 1 September 2017 (UTC)

A glitch with nitrogen as a reductive nonmetal

It appears we cannot describe N as a reductive nonmetal. That would imply that it is better as a reducing agent (when it loses electrons) than as an oxidising agent (when it gains electrons).

In fact N is both a poor reducing agent and a poor oxidising agent.

Subject to your thoughts it looks like we may have to go back to corrosive nonmetal (either that, or keep oxidative nonmetal in any event) and that we'll need to find another adjective to cover the other nonmetals. Sandbh (talk) 02:31, 3 September 2017 (UTC)

It may be true that nitrogen is neither very reducing or very oxidising. What that means, though, is that it tends to form covalent bonds over ionic bonds, as do the other five reductive nonmetals. In contrast, the oxidative nonmetals show more ionic compounds than covalent compounds. So we may go with ionic and covalent for oxidative and reductive.

Yet nitrogen is still slightly more reducing than oxidising, weak as it may be. It's either ionic/covalent, or we stick to oxidative/reductive. Parcly Taxel 04:05, 3 September 2017 (UTC)

Or what about ionogenic and covalogenic? YBG (talk) 05:09, 3 September 2017 (UTC)

Ionogenic is a real word; covalogenic would be a neologism. Sandbh (talk) 06:28, 3 September 2017 (UTC)

That's better than I thought; I figured both for neologism. Covalogenic also doesn't exactly roll off the tongue, so "ionic nonmetals" and "covalent nonmetals" will have to stand as the best ideas in this idea space. YBG (talk) 13:57, 3 September 2017 (UTC)

@Parcly Taxel: Curious. How would you show that N is slightly more reducing than oxidizing? Sandbh (talk) 06:28, 3 September 2017 (UTC)

@Sandbh: Just my hunch; you've already done the research so you should know. We can still look for other pairs of category names. Parcly Taxel 07:50, 3 September 2017 (UTC)

I've looked closer at the standard electrode potentials involving N₂ and it's too close too call one way or the other. I thought I might've missed something but it seems not. Sandbh (talk) 06:28, 4 September 2017 (UTC)

Being conscious of space limitations in the category legend boxes could we try:

• Less active nonmetal
  
• Corrosive nonmetal
  
• Noble gas

Thus, oxygen is a corrosive nonmetal, sulfur and selenium are less active nonmetals, tellurium is a metalloid, and polonium is a post-transition metal. A single "-ive" word to replace "other nonmetal" would be ideal however I'm not sure such a word exists, hence "less active". Sandbh (talk) 07:00, 4 September 2017 (UTC)

@Sandbh: Hey, at least "less active" ends in "-ive". :) It has the advantage of making all three nonmetal categories described in terms of chemical activity - the noble gases are so named because they are the least active elements, and corrosive nonmetals are so named because of they are very chemically active.

What about "covalent nonmetals"? I don't think I've seen anything negative about this term. Of course, it is actually metonymy (since it is actually the compounds, not the elements, which are covalent) but I don't think that disqualifies it. YBG (talk) 16:12, 4 September 2017 (UTC)

I hesitate using the term covalent nonmetal since O, F, Cl, Br, and I are all covalent (i.e. diatomic) nonmetals, and the fact that O, F, Cl, Br, and I form covalent compounds with the other nonmetals does not help. I feel that there is too much cognitive dissonance. I was also trying to avoid category names starting with the same letter.

I agree with you about maintaining the chemical activity sense of the proposed category names, which is a good idea. There is a similar sense among the metals, starting with the alkali metals. Sandbh (talk) 22:51, 4 September 2017 (UTC)

What about weak nonmetals or weakly active nonmetals? Essentially saying the same thing, but less overtly comparative. YBG (talk) 23:10, 4 September 2017 (UTC)

Weak or weakly active are too overtly comparative\judgemental. It implies that the other nonmetals are all weak or weakly active, whereas (being a heterogenous mob :) they show a range of properties (weak, moderate, or strong) associated with chemically active nonmetallic character. The other nonmetals are more accurately thought of as "weak to moderate" or "weakly to moderately active", rather than weak overall. This is why I prefer "less active" as it copes with a lot of territory in a relatively small title, and should convey a good amount of realistic complexity without misleading anyone. Sandbh (talk) 04:32, 5 September 2017 (UTC)

OK, but doesn't this bring us back to the problem of "intermediate nonmetals": less active than what? Double sharp (talk) 05:02, 5 September 2017 (UTC)

Maybe. Should we try(?):

• Less active nonmetal
  
• Active nonmetal
  
• Noble gas

Some explicit quotes from the literature:

• "A salt is a compound of metal ions and nonmetal ions. The halogens being active nonmetals are excellent salt-formers." (Allen et al. 1942, p. 484)
• "What, in general, is the difference between active metals, less active metals, less active non-metals, active non-metals, and inert gases…?" (Friedenberg 1946, p. 230)
• "The halogens and oxygen are the most active non-metals." (Lee & Van Orden 1965, p. 197)
• "The most active non-metals are in the upper right-hand corner of the chart; the most active metals are in the lower left-hand corner." (Luder 1965, p. 39)
• "From Group V on, the series passes from the less active nonmetals to the most active ones, like chlorine, in Group Vll." (Gardiner & Flemister 1967, p. 22)
• "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 1968, p. 234)
• "If you don't count the noble gases, Family 18, the most active non-metals are found in the upper right corner." (Aldridge 1993, p. 175)
• "Active nonmetals, such as the halogens (Group VIIA) and oxygen, are good oxidizing agents." (Grolier Incorporated 1999, p. 162)
• "Oxygen is one of the most active nonmetals and one of the most important. It forms compounds with all the elements except the light noble gases (He, Ne, and Ar). In general, oxygen forms ionic compounds with metals…" (Hill and Petrucci 1999, p. 903)

I am a little bit giddy thinking this was in the literature all along. Have we finally cracked this sucker now?

• Aldridge 1993, Science interactions, Glencoe/McGraw-Hill, New York
• Allen JS, French SJ, Woodruff JG 1942, Atoms, rocks and galaxies: a survey in physical science, Harper and Brothers
• Beiser A 1968, Perspectives of modern physics, McGraw-Hill, New York
• 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
• Gardiner MS & Flemister SC 1967, The principles of general biology, Macmillan
• Grollier Incorporated 1999, The encyclopaedia Americana, vol. 21
• Hill JW & Petrucci RH 1999, General chemistry: An integrated approach, Prentice Hall
• Lee GL & Van Orden HO 1965, General chemistry: Inorganic and organic, 2nd ed., Saunders, Philadelphia
• Luder WF 1965, General chemistry, Saunders, Philadelphia

-- Sandbh (talk) 08:12, 5 September 2017 (UTC)

I like this one very much, and it's surely great to find that it was in the literature all along! Double sharp (talk) 10:20, 5 September 2017 (UTC)

Yahoo! Sandbh (talk) 11:48, 5 September 2017 (UTC)

Like Parcly Taxel 13:31, 5 September 2017 (UTC)

 Works for me YBG (talk) 14:45, 5 September 2017 (UTC)

So it's (from today's /Nonmetal redraft):

• Less active nonmetals (6×): hydrogen (H), carbon (C), nitrogen (N), phosphorus (P), sulfur (S), and selenium (Se).
• Active nonmetals (5×): oxygen (O) and the four halogen nonmetals fluorine (F), chlorine (Cl), bromine (Br), and iodine (I).

Will adjust these names in the color-tables (not the new colors themselves). Nice improvement. It is even getting great by esthetics, this category language. -DePiep (talk) 07:50, 6 September 2017 (UTC)

• Out of category interest: by this new scale less active – active, is the border line wide? As in: do the two categories cling together strongly, and separate wide between them, on this 'active' thing? (See for example: the Lists of metalloids shows that there are four groupings recognised with diverging percentage, not a continuum: Commonly (93%), Irregularly (44%), Less commonly (24%), Rarely recognized (9%)). -DePiep (talk) 07:50, 6 September 2017 (UTC)

If one looked up 200 chemistry books, I guess effectively all would count F, Cl, Br, and I as the most active of the nonmetals. The most visible manifestation of this activeness is their corrosive nature. In numerical terms I guess it would be their oxidising power. Of the remaining nonmetals, most books would comment about the relatively avaricious (electron greedy) character of oxygen. The rest of the nonmetals generally don't get spoken of in these terms. Qualified exceptions are:

• H: Its flammability (i.e. with oxygen) is sometimes noted.
• C: Finely divided C "may heat spontaneously in air, and the presence of water accelerates this…ignition may occur if contamination by drying oils or oxidising agents occurs…[less powdered forms] "will ignite or explode on suitably intimate contact with oxygen, oxides, peroxides, oxo-salts, halogens, and oxidising species." (Bretherick's handbook of reactive chemical hazards 1999, pp. 119–120)
• N: Its high EN is often commented favourably upon and this is manifested in some associated properties namely, its capacity to form unusually strong hydrogen bonds, and its complex forming ability. Unlike O however, N is a poor oxidising agent (its needs to be in combination with O or F to become a good oxidising agent) and most of its compounds are covalent in nature. OTOH, many compounds of nitrogen are less stable than diatomic nitrogen, so nitrogen atoms in compounds seek to recombine if possible and release energy and nitrogen gas in the process, which can be leveraged for explosive purposes. Even here, however, most common explosives contain nitrogen bonded to one or more oxygen atoms. And explosives like lead azide are unstable due to bond strain in the ${\ce {^{-}N={\overset {+}{N}}=N^{-}}}$ ion. Nitrogen prefers to form a more stable triatomic bond with itself, whenever it can, as an outcome of its electron configuration, and its small size. The nitrogen molecule has an ideal configuration of molecular orbitals for all its electrons. Each nitrogen atom has three 2p electrons, making six for the pair of atoms. Each atom has three 2p orbitals; two atoms close to one another make six molecular orbitals. Three such orbitals are bonding, with favourable energy; three others are anti-bonding. Each orbital can accept two electrons of opposite spin, so the bonding molecular orbitals take six electrons = bonding heaven. P has a much harder time doing this forming a triple bond, on account of its larger size.
• P: Its reactivity varies according to its degree of catenation. White P (P₄ molecules = most unstable) > red P > (polymeric = P₄ molecules joined in chains = metastable) > black P (sheets of P = stable). According to Bretherick pp. 1885–1887), the white and red forms ignite on contact with F and Cl; white explodes on contact with Br vapour; red ignites in liquid Br; white ignites in contact with I. Red P ignites in contact with some peroxides. Mixtures of P with oxidising agents like ammonium nitrate, mercury(I) nitrate, or silver nitrate explode on impact. Black P, the most stable form, is less generally much less reactive than white P.
• S: Greenwood & Earnshaw say it is a very reactive element especially at slightly elevated temperatures. OTOH, General chemistry for colleges (Hopkins & Bailar 1956, p. 258) says: "Sulfur should be a typical nonmetallic substance, but since the nonmetallic properties decrease as the atomic weight increases we should expect sulfur to be less active than oxygen. This decrease in chemical activity is so evident that we shall do well to contrast the activity of oxygen with the chemical inertia of sulfur."
• Se: From my reading of Bretherick, selenium appears to be less than or equal to as reactive as sulfur, e.g. with oxidising agents and some metals (especially but by no means exclusively, the powdered forms of these nonmetals).

Having said all of that none of the less active nonmetals can match the oxidising power of the active nonmetals without help from oxygen (or F), and none of them match or surpass any of the active nonmetals across all three properties of electronegativity, electron affinity, and ionisation energy, these properties being prominently correlated with nonmetallic character.

So the border line has little overlaps here and there but it's reasonably wide, overall. Sandbh (talk) 00:41, 8 September 2017 (UTC)

New colors

Two newly defined categories are created, so we need two new colors. It is fundamentally wrong to re-use existing colors for a different category. IOW, the green (polyatomic) and yellow (diatomic) will be abandoned together with their category. I propose these new colors:

•    Less active nonmetals → transparent  [green] (Corrosive nonmetal) H, C, N, P, S, Se.
•    Active nonmetals → transparent  [yellow] (Other nonmetal) O, F, Cl, Br, I.

(Adjusted, new new category names. DePiep (talk) 07:57, 6 September 2017 (UTC))

They are only slightly different from the old ones, because green and yellow fit nicely in the set. The names used (e.g. in {{Element color}}) are those proposed by Sandbh. If a name would change before going live, we'll adjust it here. Please use these colors in further proposals. -DePiep (talk) 13:43, 25 August 2017 (UTC) (This is only about using new and different color numbers. No prejudice is made on the new category names & definitions. At all. -DePiep (talk) 20:59, 25 August 2017 (UTC))

Solved

Could I check that you have the colours the right way around? We currently show the diatomics as yellow, which is a holdover from when we showed the halogens as yellow. I also think the metalloids are brown because IIRC that was a colour between post-transition metal grey and polyatomic green. Presumably then that the corrosives would be yellow, and the other nonmetals green, or are you proposing to swap the colours? Sandbh (talk) 23:48, 25 August 2017 (UTC) No green/yellow swap! Per User:Sandbh/Nonmetal redraft:    Polyatomic nonmetal → #a1ffc3  = green:C P S Se    Diatomic nonmetal → #e7ff8f  = yellow: H N O F Cl Br I    Corrosive nonmetal → #f0ff8f  = green: O F Cl Br I formerly green, now yellow YBG (talk) 08:08, 26 August 2017 (UTC)    Other nonmetal → #a0ffa0  = yellow: H C N P S Se formerly yellow, now green YBG (talk) 08:08, 26 August 2017 (UTC) Please tell: "corrosive nonmetals" should be green or yellow? -DePiep (talk) 00:19, 26 August 2017 (UTC) I'm in favour of having the oxidative (corrosive) nonmetals yellow and the reductive (other) nonmetals green to keep the present order of the colour bands. As it stands above, the colours would actually be swapped. Parcly Taxel 00:47, 26 August 2017 (UTC) By now, I follow Sandbh — blindly. -DePiep (talk) 00:56, 26 August 2017 (UTC) I agree with what Sandbh and Parcly Taxel have stated above, that corrosive nonmetals should be yellowish and other nonmetals should be greenish. YBG (talk) 06:12, 26 August 2017 (UTC) I note that this also appears to be Sandbh's intent in User:Sandbh/Nonmetal redraft. YBG (talk) 06:18, 26 August 2017 (UTC) I have just now edited {{element color/secondary}} to make corrosive NM yellowish and other NM greenish. This will automatically change the colors above, which may make the discussion a bit difficult to follow. YBG (talk) 08:04, 26 August 2017 (UTC) Not helpful, YBG. -DePiep (talk) 09:25, 26 August 2017 (UTC)

• New new category names: Less active nonmetals, Active nonmetals. Changed (not colors themselves). -DePiep (talk) 07:57, 6 September 2017 (UTC)

Interwiki changes

Our PT images are used on many wikis. See File:Periodic Table Chart.png for example. Often these wikis use it in the blind. I wonder, if we make this NNNM change in these images, should we overwrite the old one, or create a new file? If we overwrite, the legend is not correct any more in these other wikis. -DePiep (talk) 17:52, 25 August 2017 (UTC)

See also #WP:PTCC below. -DePiep (talk) 22:54, 25 August 2017 (UTC)

Proposal: Colour group 12 as post-transition metals

The following discussion is an archived record of a request for comment. Please do not modify it. No further edits should be made to this discussion. A summary of the conclusions reached follows.

Consensus was reached to color code the group 12 elements as post-transition metals Sandbh (talk) 06:07, 1 September 2017 (UTC)

---

(Done at the prompting of Sandbh on my talk page; thank you!)

Earlier discussions:

• Archive 16#Make_the_group_12_elements_poor_metals (August 2013, multiple sources)

In the IUPAC Red Book, two definitions of "transition metal" are given: one is groups 3–12, while the other is groups 3–11. The exact quote is "the elements of groups 3–12 are the d-block elements. These elements are also commonly referred to as the transition elements, though the elements of group 12 are not always included".

Now, the last time we proposed this colour change for group 12, it got steamrolled by the fact that "poor metals" is a name that nobody uses outside PT fans. Now that we use "post-transition metals", it seems that a second look at this is justified, as the situation is different. As another example of changing situations, at our previous look, HgF₄ seemed to be a real compound and CnF₄ was predicted to be possible; however, new experiments have not found any evidence of HgF₄, and newer calculations also cast serious doubt on the existence of Cn^IV.

By the time we get to group 12, there is no transition-metal-like chemistry, and as can be seen from the abrupt drop in melting and boiling points, there is no longer any cohesive effect from the d-electrons – unlike group 11 (which has a clear mix of main-group and transition properties), and group 3 (for which the d-electrons still contribute physically, even if their chemistry is basically that of trivalent versions of Ca, Sr, and Ba). Even when relativistic effects are in play, where the relativistic maximum in period 7 is expected to happen at Cn instead of Rg (it happens at Au in period 6), there is a big increase in volatility expected between Rg and Cn, and the high volatility is expected to stay all the way to Og.

Hence I would like to propose once again that we recategorise Zn, Cd, Hg, and Cn from "transition metals" to "post-transition metals", following the simple IUPAC-approved group 3–11 definition. There would be no need to look through predicted transactinide chemistry and search for 6d chemistry; they can simply follow their appropriate groups, so that Mt, Ds, and Rg continue being predicted transition metals, for example. Double sharp (talk) 14:43, 26 July 2017 (UTC)

Seems sensible to me, given (1) IUPAC statement and (2) the agreed primacy of chemical properties. YBG (talk) 15:28, 26 July 2017 (UTC)

I am quite indifferent on this one, be it one way or another. But have you considered inviting WP:CHEM and WP:CHEMS to get more opinions? It's fifty-fifty in the literature for a reason.--R8R (talk) 15:32, 26 July 2017 (UTC)

Never mind about second opinions. Since the group 12 elements have filled subshells but the transition metals show varied oxidation states mainly because of their unfilled subshells, you might as well go ahead and recolour the former set of elements as PTMs. Parcly Taxel 16:58, 26 July 2017 (UTC)

re Never mind about second opinions: this indifference to quality reasoning sounds a bit ... indifferent, Parcly Taxel. If it's that sidetopical, that's an argument too to not change anything. But actually, I'd like to hear & read: in which article(-section) will this be described & motivated? We from WT:ELEMENTS cannot just impose this on our readers. -DePiep (talk) 20:31, 26 July 2017 (UTC)

Nearly effectively everyone agrees that 3–11 are transition metals. The fact that it's about 50-50 when it comes to treating group 12 as transition metals suggests to me that the default position should be 3–11, unless a robust case can be made for 3–12. I know which side I'd want to be on.

My impression is that 3–12 are treated as transition metals at least in part due to (a) a misguided conflation with the d block metals: (b) the previous absence of a good name for the group 12–16 metals; and (c) the "tail wagging the dog" phenomenon, wherein a minority of similarities the group 12 metals have with the transition metals is used to leverage the whole group into the same category as the transition metals.

For example, the transition metal article says:

• [1] "When discussing the crystal field stabilization energy of first-row transition elements, it is convenient to also include the elements calcium and zinc, as both Ca²⁺ and Zn²⁺ have a value of zero against which the value for other transition metal ions may be compared.

The same article goes on:

• [2] "Another example occurs in the Irving-Williams series of stability constants of complexes."

The first example strikes me as highly dubious given Ca is effectively never categorised as a transition metal.

The second example is elaborated in the Group 12 element article: "…they [group 12] share many characteristics with the neighboring group 11 elements on the periodic table, which are almost universally considered to be transition elements…Zinc complexes merit inclusion in the Irving-Williams series as zinc forms many complexes with the same stoichiometry as complexes of copper(II), albeit with smaller stability constants." My response to this is to note that (according to Advanced Inorganic Chemistry, Cotton et al. 1999, p. 598) zinc forms none of the other typical sorts of transition metals complexes i.e. the similarity is passing rather than substantial.

The same article goes on to say that, "There is little similarity between cadmium and silver as compounds of silver(II) are rare and those that do exist are very strong oxidizing agents. Likewise the common oxidation state for gold is +3, which precludes there being much common chemistry between mercury and gold, though there are similarities between mercury(I) and gold(I) such as the formation of linear dicyano complexes."

I don't see anything here that warrants categorising group 12 as transition metals.

Smith's approach in Inorganic Substances: A Prelude to the Study of Descriptive Inorganic Chemistry (1990, p. 113) is wise: "Textbook writers have always found difficulty in dealing with these elements. In this book, they will be placed with either the transition elements or the Main Group elements, as the occasion demands." So yes, categorise them as post-transition metals, and feel free to include or make reference to them in the transition metal article or the Irving-William series article, for comparative purposes.

It is tempting to be bold but I don't want us to be reverted. So, I suggest putting a formal proposal at Talk: Periodic table and notifying WP:CHEM, WP:CHEMS, and Template talk: Periodic table, and seek to establish consensus (which does not require unanimity of opinion, as Double sharp reminded me a while back).

Alternatively, act first, and then go for consensus if we get reverted. Sandbh (talk) 06:46, 27 July 2017 (UTC)

Feel free to go ahead with the formal proposal. As for where the distinction between groups 3–11 and group 12 will be discussed, I suggest discussing it on the post-transition metal page, explaining why group 12 has been included there. Parcly Taxel 06:54, 27 July 2017 (UTC)

Thanks Double sharp and Sandbh for clarifying this issue, including its confusing RL history. It all looks much well-sourced & simpler now. This being uber periodic table (a dozen of articles and all PT images), an RfC might as well be opened here (not Talk:PT) with advertisements around. Consensus by RfC makes another very strong case (into 'standardising' the enwiki classification scheme wiki-wide and possibly even outside). -DePiep (talk) 09:36, 27 July 2017 (UTC)

I think the fact of having an RfC might even be more important than where it is, given the one at Template talk:Periodic table deciding on a Sc-Y-La-Ac group 3. I think Sandbh would write a better and more well-researched opening statement than I would, though. ^_^ Double sharp (talk) 15:11, 27 July 2017 (UTC)

I think Sandbh would be a good person to write it up. YBG (talk) 15:21, 27 July 2017 (UTC)

Sandbh doing this bold: OK with me. He already described the risk. I just wanna say: our cat&color-thing here is so sound, we'd wanna have it wider than just enwiki (as with group 3).

Also, our current (2013 CAT) images & tables are used on many lang-wikis, even blindly I think. New 2017 CAT images should be a new file (do not overwrite 2013).

Detail: "group 3" was about the PT itself, but this is just about group 12.

About Cn: will it be still in? Cn was convincingly made "Transition metal", while it mostly has speculations. (mean Q:) Now it is this easily changed into a PTM? :-DePiep (talk) 21:45, 27 July 2017 (UTC)

reply by Double sharp (here): "Yes, Cn will fit OK as a PTM, because chemical experiments have shown that it behaves like a typical group 12 member, and by the group-based definition group 12 would be a PTM group. There was originally room for doubt based on the expected existence of Cn^IV, but given that newer calculations have refuted this (see copernicium) that has vanished." (end of quote). -DePiep (talk) 10:54, 28 July 2017 (UTC)

I'm happy to draft the RFC proposal and will do so, subject to RL commitments. Sandbh (talk) 23:06, 28 July 2017 (UTC)

RfC: Colour group 12 as post-transition metals

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

The origin of this proposal can be traced to a 1983 article by Bill Jensen, in the Journal of Chemical Education, here, in which he noted that there was "roughly a 50–50 split between those texts that included the Zn group among the transition metals versus those that did not." In the same article he gave supporting arguments for treating group 12 as other than transition metals.

IUPAC does not take a firm position on this question. They say that groups 3 to 12 are the d-block elements and that these are commonly referred to as transition metals though group 12 is not always included (see here, p. 51). Certainly, the group 12 elements do not satisfy the IUPAC Gold Book definition of a transition metal, which is "An element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell."

Most of the chemistry of group 12 is that of main group elements rather than transition metal chemistry. This is due to d-shell being inaccessible in these elements. Physically, there is a related abrupt and significant reduction in metallic character going from group 11 to group 12.

My impression is that groups 3–12 are treated as transition metals at least in part due to (a) a misguided conflation with the d-block metals: (b) the previous absence of a good name for the group 12–16 metals; and (c) a "tail wagging the dog" phenomenon, wherein a minority of similarities the group 12 metals have with the transition metals is used to leverage the whole group into the same category as the transition metals.

For example, the transition metal article says:

[1] "When discussing the crystal field stabilization energy of first-row transition elements, it is convenient to also include the elements calcium and zinc, as both Ca²⁺ and Zn²⁺ have a value of zero against which the value for other transition metal ions may be compared."

The same article goes on:

[2] "Another example occurs in the Irving-Williams series of stability constants of complexes."

The first example strikes me as highly dubious given Ca is effectively never categorised as a transition metal.

The second example is elaborated in the Group 12 element article:

"…they [group 12] share many characteristics with the neighboring group 11 elements on the periodic table, which are almost universally considered to be transition elements…Zinc complexes merit inclusion in the Irving-Williams series as zinc forms many complexes with the same stoichiometry as complexes of copper(II), albeit with smaller stability constants."

My response to this is to note that (according to Advanced Inorganic Chemistry, Cotton et al. 1999, p. 598) zinc forms none of the other typical sorts of transition metals complexes i.e. the similarity is passing rather than substantial.

The Group 12 article goes on to say that, "There is little similarity between cadmium and silver as compounds of silver(II) are rare and those that do exist are very strong oxidizing agents. Likewise the common oxidation state for gold is +3, which precludes there being much common chemistry between mercury and gold, though there are similarities between mercury(I) and gold(I) such as the formation of linear dicyano complexes."

I don't see anything here that warrants categorising group 12 as transition metals.

Smith's approach in Inorganic Substances: A Prelude to the Study of Descriptive Inorganic Chemistry (1990, p. 113) strikes me as wise: "Textbook writers have always found difficulty in dealing with these elements. In this book, they will be placed with either the transition elements or the Main Group elements, as the occasion demands."

So yes, categorise them as post-transition metals, and feel free to include or make reference to them in the transition metal article or the Irving-William series article, for comparative purposes.

There was a flurry of excitement a little while back when it seemed that HgF₄ was a real compound and CnF₄ was predicted to be possible (and hence both Hg and Cn could arguably have perhaps been regarded as transition metals, since such compounds would require the involvement of either 5d or 6d electrons), however new experiments have not found any evidence of HgF₄, and newer calculations also cast serious doubt on the existence of Cn(IV).

The fact that (a) nearly effectively everyone agrees 3–11 are transition metals; (b) it's about 50-50 when it comes to treating group 12 as transition metals; (c) IUPAC is either no help or contradictory; (d) the chemistry of group 12 is very largely main group chemistry, suggests to me that the default position for categorising transition metals should be 3–11, unless a robust case can be made for 3–12. In my view, there is no such case. As noted, if group 12 were to be categorised as post-transition metals, they can still be referred to, for comparative purposes, in e.g. the transition metal article.

Sandbh (talk) 05:42, 8 August 2017 (UTC)

Comments

• Should be invited IMO: WT:CHEMISTRY, WT:CHEMICALS, WT:ELEMENTS, ... -DePiep (talk) 22:24, 9 August 2017 (UTC)

Done. Also posted to Template talk:Periodic table, Talk:Perioidic table, Talk:Group 12 element, Talk:Tranisition metal, and Talk:Post-transition metal. Sandbh (talk) 23:19, 9 August 2017 (UTC)

• About "category" and "color".

In periodic tables, this enwiki uses category for sets of elements that are classified (grouped) by their metallicity. There are ten categories, from alkali metals to noble gases; they show a trend (pattern) in the periodic table. The word "category" is used only in this enwiki grouping: there is no standard IUPAC word for it (while group, period are well-defined).

Also in enwiki, each category has its own, same color in every periodic table shown.

So when this RfC says 'recolor elements', it means 'change [enwiki] category'. -DePiep (talk) 21:13, 12 August 2017 (UTC)

Survey

• Support (both the wording and the position). Parcly Taxel 07:24, 8 August 2017 (UTC)
• Support as proposal nominator. Sandbh (talk) 23:20, 9 August 2017 (UTC)
• Support. In practice, we are already doing this in the more advanced chemistry articles: for example, Metal ions in aqueous solution mentions at one point the "transition metals and group 12 metals". The reason is obvious: the group 12 elements have so little transition-like chemistry that trying to force them in regardless always results in the need to cover their distinct behaviour separately. The change here is that we would then start from a reasonable foundation, instead of lying to children and conflating the d-block with transition chemistry. It just isn't so. Double sharp (talk) 01:00, 10 August 2017 (UTC)
• Support. A well-written proposal that details the subtle reasoning behind it clearly enough for those (like me) whose knowledge of chemistry is at the broad-brushstrokes level. YBG (talk) 02:54, 10 August 2017 (UTC) clear→clearly YBG (talk) 05:34, 15 August 2017 (UTC)
• Support. (I've sometimes wondered why zinc is classified as a transition element, while failing to behave as one.) Maproom (talk) 07:38, 13 August 2017 (UTC)
• Support. It occurs to me that (especially in the 2013 discussion), counter-arguments are (1) categorisation of these poor metal/post-transition elements is not strong, useful or meaningful enough, and (2) falling back on non-category criteria, like relying on properties block and group/valence. Well, (1) may be true, but then categorising on a less strong basis is acceptable too, especially since we do categorise all elements (we don't want less-clear elements to be colored white), and it does show a trend. And (2) defies the essence of categories: that they can form a new pattern in the periodic table (as the metalloids clearly show: a tetris area), unrestricted by other classifications like block or group. On top of this, the topic is well sourced. -DePiep (talk) 13:41, 13 August 2017 (UTC)

I add: this argument (3) is looming around: because the borders of categories (border elements) are extra uncertain on top of the "50/50" category definition itself, we more so should stay away from categorising. IMO, yes (3) is true, but we still can make a well-based decision (choice) in this greyish area, reading the sources. This wiki also made an intelligent solution wrt metalloids. Such subtleties can be detailed in dedicated articles & sections, while retaining the overall intention: show the trend in the periodic table. -DePiep (talk) 15:34, 13 August 2017 (UTC)

• Support per YBG. Keira1996 04:30, 15 August 2017 (UTC)
• Support. (Summoned by bot) For reasons given above. Roches (talk) 12:40, 15 August 2017 (UTC)

re Roches: What is "(Summoned by bot)"? Are you not free? -DePiep (talk) 00:27, 26 August 2017 (UTC)

@DePiep: I know you weren't asking me, but "(summoned by bot)" is nicely explained in {{sbb}}, which is visible in the wikitext of Roches's !vote. YBG (talk) 06:30, 26 August 2017 (UTC)

• Question What is the process for closing an RfC like this? It looks like WP:Snow to me. YBG (talk) 06:30, 26 August 2017 (UTC)
• Support See this source[1]. Tornado chaser (talk) 16:02, 26 August 2017 (UTC)

Discuss

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Rare-earth metal: adjective

Recently, we can see edits (by Mikhail Ryazanov [2]) that change "rare earth metal" into "rare-earth metal". Grammarly correct I understand (rare is an adjective), but does it fit with our world view (iconic names)? -DePiep (talk) 22:23, 11 August 2017 (UTC)

The grammatically correct (hyphenated) version is used in reliable sources (for example), so I see no reason to use the wrong one here. Especially since, as the WP article mentions, "rare-earth elements" are actually not so rare, thus the hyphenated version is also less confusing. — Mikhail Ryazanov (talk) 23:12, 11 August 2017 (UTC)

Curiously, the IUPAC approved term is "rare earth metal". As our article notes, while they aren't especially rare they're typically dispersed and not often found concentrated in economically exploitable ore deposits, hence they are rare in that sense. It's interesting to see that the reliable source calls them "rare earths" elsewhere in the article. The Google Books Ngram viewer, here, shows that in 2008 "rare earth elements" was the most popular form by a 3:1 ratio. The 2008 ratio for rare earth metal to rare-earth metal, here, was 2:1 in favour of the former. Sandbh (talk) 01:29, 12 August 2017 (UTC)

Set the Ngrams to analyse more generic "rare-earth,rare earth" +s [3]. -DePiep (talk) 10:41, 13 August 2017 (UTC)

Take into account that "rare earth" might be a noun phrase (one of "rare earths") or improperly capitalized "rare Earth ...", which should not be hyphenated. (And "rare-earths" would be something strange.) Nevertheless, the usages looks comparable and, as I mentioned, probably depend on the publisher preferences. — Mikhail Ryazanov (talk) 04:31, 14 August 2017 (UTC)

So "rare-earth metals" as a term are not rare either. ;–) And the hyphenation or its absence is probably just reflecting the house style, which in our case recommends the hyphenated form. (BTW, my impression is that IUPAC is not even internally consistent regarding hyphenation and other notation, so the exact way they write something is probably not too important.) — Mikhail Ryazanov (talk) 01:54, 12 August 2017 (UTC)

To be sure, for any other IUPAC defined name such a change must be discussed beforehand, likely here. IOW it's controversial. It is not established that the earlier form is "wrong". -DePiep (talk) 08:54, 12 August 2017 (UTC)

• The IUPAC Red book p. 63/pdf, paragraph IR-3.5, recommends: "rare earth metal", "alkaline earth metal", not hyphened. I suggest we stick to this recommendation (as we do for aluminium, caesium, sulfur. BTW, there is no mention of "post-transition metals" so that can stay hyphened. Also, "f-block" is hyphened). The point is that it is a given name, not a description. Once we'd check the description for correctness, one can also end up proposing "actually not-so-rare-earth elements". I propose to remove the hyphen. -DePiep (talk) 11:20, 13 August 2017 (UTC)
  • Strictly speaking, IUPAC only mentions "rare earth metals", so "rare earths" or "rare-earth elements" (regardless of hyphenation) are not "IUPAC-approved" in that sense. However, the WP article is called "... elements" rather than "... metals", and it seems that "elements" are used more than "metals". Does it meant that we need to go and change all these "elements" to the IUPAC-approved "metals". Probably, not. And again, I do not believe that the lack of hyphen in that IUPAC publication is significant. — Mikhail Ryazanov (talk) 04:31, 14 August 2017 (UTC)

Off topic. Issue is whether "rare earth" is defined in adjective or in name form. -DePiep (talk) 18:14, 14 August 2017 (UTC)

"Rare earth" is not defined at all. The only occurrence is "rare earth metals", without any explanations.

Do you have any ideas how to contact IUPAC for clarification? I could not find any reasonable contact information in the book or on the website (writing to the secretariat is probably hopeless). I have a friend who apparently works in the same building as Fabienne Meyers (the IUPAC Associate Director) and can try to ask through her, but a more direct and official way would be better. — Mikhail Ryazanov (talk) 03:04, 15 August 2017 (UTC)

sigh. The topic is: the spelling of r.e. With or without hyphen? Is it a name or regelar words (ie grammatically adjective)? We know what iupac approves. Contact=red book. -DePiep (talk) 15:15, 15 August 2017 (UTC)

What do you mean by "name"? Proper names must be capitalized. Other terms are, grammatically, regular words. — Mikhail Ryazanov (talk) 23:23, 15 August 2017 (UTC)

"Name" as in: frozen, irrespective of their descriptive history. Word(s) with a meaning by themselves. And btw, names of chemical elements are proper and not capitalised. -DePiep (talk) 13:51, 25 August 2017 (UTC)

Can you recommend a book or article when I can read about these ideas? From what I know, names of chemical elements are not proper; neither are names of subatomic particles, chemical compounds, allotropes, minerals and so on. — Mikhail Ryazanov (talk) 03:14, 27 August 2017 (UTC)

Help with theoretical stuff

I'm working on a project involving theoretical elements, so I'm trying to make a reference page for it. Can someone here help me fill out the missing electrons per shell counts in this section? It starts with 122. I haven't done anything with chemistry for over 27 years. I appreciate any help. ···日本穣 · 投稿 · Talk to Nihonjoe · Join WP Japan! 03:10, 12 August 2017 (UTC)

@Nihonjoe: You can find them all at Electron configurations of the elements (data page), but do note that because of the insertion of the g-block, you don't get back to group 4 until element 158. Double sharp (talk) 08:09, 12 August 2017 (UTC)

@Double sharp: Sadly, I don't undertand how to read that information. I don't understand the notation. I haven't done any chemistry for over 27 years. ···日本穣 · 投稿 · Talk to Nihonjoe · Join WP Japan! 19:13, 12 August 2017 (UTC)

@Nihonjoe: The bottom rows (below all the spdf stuff) give the counts per shell. For example, if you look at the row for lutetium, element 71, the first row gives "[Xe] 4f¹⁴ 5d¹ 6s²", and the second row breaks that down, but the third row has "2, 8, 18, 32, 9, 2" as you want. Double sharp (talk) 04:16, 13 August 2017 (UTC)

@Double sharp: So each shell can have multiple orbitals in it? ···日本穣 · 投稿 · Talk to Nihonjoe · Join WP Japan! 16:14, 13 August 2017 (UTC)

Shell = Electron shell (K, L, M, ...), principal quantum number n = 1, 2, 3, ... .

Orbital = Atomic orbital: " is characterized by a unique set of values of the three quantum numbers n, ℓ, and m"

-DePiep (talk) 19:09, 13 August 2017 (UTC)

@Nihonjoe: Yes. Atomic orbital may help. Double sharp (talk) 23:54, 14 August 2017 (UTC)

Infobox element: placement of atomic weight

Currently, {{Infobox element}} has standard atomic weight (aka atomic weight; A_r) in its section "[Hydrogen] in the periodic table". I propose to move Atomic weight into the isotopes section "Main isotopes of [hydrogen]". Either above or (preferably) below the isotopes table in there. For instable elements we mention "mass number (most stable isotope)", which could go there too. No formatting changes in play.

Quite simple, atomic weight has nothing to do with the periodic table (ask Mendeleev). Putting it with the isotopes is more obvious. IMO most logical is below the table (as this infobox already has), as a summary result of the abundances. Above the table might be considered for the importance of this value, but less logic.

A negative is that this is the very bottom of the infobox for such an important value, that did win people Nobel prizes (even worse with all that Miscellaneous data taking space & attention, like a garden shed that needs cleaning up or complete removal). In this, I prefer logical consistency. -DePiep (talk) 15:13, 13 August 2017 (UTC)

Atomic weight is actually pretty disproportionately useful because you need it for just about every chemistry calculation of significance right from the first year, so I would perhaps be willing to consider it a case where extreme utility means it is a worthy exception to the scheme. Surely it should give one pause when one considers that atomic weight tends to get top billing in most printed periodic tables, behind only the chemical symbols, element names, and atomic numbers. Double sharp (talk) 15:27, 13 August 2017 (UTC)

In that case, move to upper "General properties"? (taking the risk of scaring readers away given the value format...) -DePiep (talk) 15:38, 13 August 2017 (UTC)

Enter topic 'simplify for reader, complicate for us editors': IUPAC also publishes an "abridged" value (think: rounded to 5 sigfig, usually with a (1) uncertainty. A_{r, abridged}(He) = 4.0026 i.e. 4.0026(1)). We could add that for every element, to ease the eye of the reader. The H: [x, y] elements (12×) already do this, as the 'conventional' value. -DePiep (talk) 16:48, 13 August 2017 (UTC)

I think that would be fine. Double sharp (talk) 23:57, 13 August 2017 (UTC)

On second thought, I do not want it under "General properties". Information should be presented structurally, not by popularity. Whether it is "useful" (as you say) is not very eh useful (should order properties by usefulness?). Maybe you mean "it's important", but that can be said about everything in the infobox—otherwise, it shouldn't/wouldn't be in there. The infobox is not a personal scrapnote. We should keep aiming for systematic presentation of the info, and so with isotopes is most logical. -DePiep (talk) 18:21, 14 August 2017 (UTC)

Except that if you put it all the way there at the bottom hardly anyone is going to find it. And yes, I would argue that atomic weight is much more important than almost anything else we currently have there. Double sharp (talk) 23:53, 14 August 2017 (UTC)

Putting it in a random place does not help finding at all. What is missing is a WP:INFOBOX-approach. I've maintained similar {{Infobox element}}, {{Infobox drug}} and {{Chembox}} for some years now, and everybody finds 'their' parameter hugely important, it Must Be In Top (see for example the external links (!) being in top of {{Chembox}}). Nobody takes an approach from infobox perspective. So Double sharp, if the bottom of the box is deemmed out of sight, how would you improve that situation? -DePiep (talk) 18:17, 16 August 2017 (UTC)

We can of course remove some of the less important information, especially in the "Miscellaneous" section. But when something is literally in just about every printed periodic table that chemists refer to, as atomic weight is, perhaps it really is hugely important and deserves a prominent spot on a par with the very name and symbol of the element. Already in the first year of chemistry you learn to use atomic weights to do just about all the standard stoichiometric calculations (e.g. deriving empirical formulae, mole ratios of reactants and products, finding limiting reagents), and then even further when dealing with gases, equilibria, and so on, all before one is done with high school. I cannot think of a single branch of chemistry where this isn't important, unlike perhaps what you could say for some of the isotopes. Sure, it may look logically in the wrong place, but it is so fundamental that I would argue strongly in favour of WP:IAR in the interests of common sense. Double sharp (talk) 03:29, 17 August 2017 (UTC)

I couldn't agree more. Atomic weight is so important it must be close to the top. Ulflund (talk) 05:32, 17 August 2017 (UTC)

I agree with Double sharp as to the fundamental importance of atomic weight in chemistry. Sandbh (talk) 09:48, 17 August 2017 (UTC)

Atomic weight, valence, being radioactive, electron config, metallicity, phase at STP: all properties that are shown "literally in just about every printed periodic table". Should all these get an exception, and go in top then? I am not discussing let alone denying importance, I am asking how to organise the infobox with this. A reader is not helped having to look for data in an irregular, illogical place (why should valence be in its structured place, and atomic weight not?). Why would a reader not find data in the place it is expected? Or is this admitting the the infobox has gotten useless, and we only keep it up by exceptions? We only want changes that prevent the need for exceptions. -DePiep (talk) 16:32, 24 August 2017 (UTC)

I am not sure if you have seen one of those periodic tables that chemists actually refer to and use instead of hang on the wall to look pretty, but in those the only three properties that you are guaranteed to find are chemical symbol, atomic number, and atomic weight.

You will not find valence because beyond basic school chemistry it is not the most well-defined of concepts; electron configuration is easily determined anyway from the element's position, bearing in mind a few exceptions, and is also usually omitted; radioactivity is easily remembered as "43, 61, everything past 83" and I have never seen it there in a serious table; metallicity and phase at STP are easily remembered by the few that are not the default "solid metal" and are often omitted, combined with some of those tables that put "synthetic" as if it were a state! But atomic weight cannot easily be so deduced and is useful everywhere.

If the idea is to prioritise slavish devotion to organising principles over putting fundamental information in a proper place to reflect how fundamental it is, I am 100% in favour of the latter and common sense. Perhaps this is not evidently common sense unless you remember high school chemistry, but I do not see how anyone who does can possibly argue against it. Double sharp (talk) 23:39, 24 August 2017 (UTC)

As predictably expected, the list I provided is made moot by ad hoc treats into non-exception. Still not an infobox approach on how to present information (even "can be deducted so is not important" is an argument now?!). Instead, carefulness is called "slavish devotion". -DePiep (talk) 07:58, 25 August 2017 (UTC)

I'd say that atomic weight is of such an importance that it should be even more visible than the various properties listed under "<element> in the periodic table". And it does appear (ever so) slightly anomalous in amongst the PT properties, which are all directly related to periodicity. So count this as a vote to promoting atomic weight to the "General properties" section. But I'm fine with leaving it in its present location. YBG (talk) 23:51, 24 August 2017 (UTC)

YBG, atomic weight has nothing to do with PT position. So current placement is wrong. -DePiep (talk) 08:00, 25 August 2017 (UTC)

 Done into General properties now. -DePiep (talk) 11:53, 25 August 2017 (UTC)

Infobox element: STP, room temperature, etc.

I have added to {{Infobox element}} Phase (at STP).

In general, we should consider if we should use also "at room temperature" data. For example, density has six options: /testcases#density. Even m.p and b.p. should be mentioned for "STP" (P then). Only exception that requires lists: allotropes like with carbon (diamond, graphite). Shouldn't we standardise this? -DePiep (talk) 19:34, 13 August 2017 (UTC)

I generally think of these things in terms of "ambient conditions" which I've always imagined to be equivalent to "room temperature", whatever that is, and ordinary pressure (1 atm). Looking at our STP article, these conditions are referred to as NTP or normal temperature and pressure = 20° C and 1 atm. What bothers me about IUPAC's ST of 0 °C is that grey tin is supposed to be the stable form of tin at temperatures below 13.2 °C. The transformation from white tin to grey tin is supposed to be sluggish, and needs an extended time below 13.2 °C to become significant but, even so, I'm sure that if the international kilogram prototype was based on 1kg of tin, that it wouldn't be maintained at a temperature of 0°C. MP and BP should, of course, be as at 1 atm. I expect all of the date in our Infoboxes for the elements ought to be at NTP, unless otherwise specified. Sandbh (talk) 01:56, 19 August 2017 (UTC)

The transformation starts sluggish, but it is autocatalytic, so once it starts, it tends to start going more and more quickly. If you want temperature alone to do the trick, you need something around −30 °C for it to happen with any sense of urgency, but alloying the tin with germanium (which has the right crystal structure) will help it along even at higher temperatures. Other than that, I certainly agree with Sandbh. Double sharp (talk) 02:58, 19 August 2017 (UTC)

[IUPAC Gold Book] says: "Standard pressure: Chosen value of pressure denoted by p ⦵ or p °. In 1982 IUPAC recommended the value 10⁵ Pa, but prior to 1982 the value 101 325 Pa (= 1 atm) was usually used." So the 1 atm is pre-1982.

[gold book STP]: "STP: Abbreviation for standard temperature (273.15 K or 0 °C) and pressure (10⁵ Pa); usually employed in reporting gas volumes. Note that flow meters calibrated in standard gas volumes per unit time often refer to volumes at 25 °C, not 0 °C."

Could not find 'room temperature' in the gold book. I find "near room temperature" not sounding very exact.

So, the modern IUPAC recommendation would be "STP = 10⁵ Pa, 0 °C".

The phrasing could be like: "All values at STP where applicable, unless otherwise noted". Special situations (like tin behaviour) can be mentioned as exceptions. Of course we should have sources for STP values. This could be a long-term changeover. -DePiep (talk) 14:24, 19 August 2017 (UTC)

I am not too keen on following IUPAC when it documents what is not yet common usage, but is envisioned as a future standard. I daresay that if you go on an expedition to a library and find a shelf full of old chemistry textbooks, you will find the remains of dozens of fallen standards, each envisioned to be permanent at their inception, and each forgotten utterly, with not even their memory remaining as you walk back out the door. We even have a basic precedent in our continued use of "lanthanide" and "actinide" instead of "lanthanoid" and "actinoid" respectively. As might be expected from the word "standard" in the name "standard temperature and pressure", there are at least seventeen different standards in current use throughout the world. I have a soft spot for 298 K and 1 atm because that's what I learned in school, but whatever we choose, we shall have to define it explicitly in the infobox too. Double sharp (talk) 14:34, 19 August 2017 (UTC)

Of course this is not to push a standard upon chemistry. It is to use a single standard in the infoboxes (not: some STP for one property, and 'near room temperature' for another). And then we need sources that publish values with that standard. -DePiep (talk) 16:39, 24 August 2017 (UTC)

But how do we choose which standard? Double sharp (talk) 23:42, 24 August 2017 (UTC)

A (modern) standard that has most/best sources over multiple properties. If RL chemistry still does not converge into one, I'd be surprised. -DePiep (talk) 08:04, 25 August 2017 (UTC)

Unfortunately, you will then be surprised at the variety even today between 10⁵ Pa and 1 atm, as well as that between 273 K, 293 K, and 298 K. T_T Double sharp (talk) 08:15, 25 August 2017 (UTC)

Well, I shouldn't be of course. First remark stands: a standard that is broadly used in sources. -DePiep (talk) 15:33, 25 August 2017 (UTC)

I asked the Bureau international des poids et mesures at which temperature they maintained the international prototype of the kilogram at and they advised "The international prototype of the kilogram is currently in an air-conditioned room maintained at 20 °C." Sandbh (talk) 22:44, 21 August 2017 (UTC)

That would be "air-conditioned room temperature" then, one more standard (by BIPM!). Methinks this would involve humidity too. -DePiep (talk) 14:35, 10 September 2017 (UTC)

• Double sharp. I get the strong impression that you are only disrupting a talk without seeking for improvement. What you wrote is cherry picking the negatives, without building into something better. Did you read the thread at all, and its essence? -DePiep (talk) 23:42, 25 August 2017 (UTC)
  • I did, of course, and I do think having this sort of standard is a good idea. The only question is what standard to pick, especially since a lot of sources for our data (e.g. densities of the elements (data page)) rather annoyingly just say "room temperature" without saying what standard for room temperature they are picking. Double sharp (talk) 03:39, 26 August 2017 (UTC)

Bad weather weeks over here, apparently. -DePiep (talk) 14:32, 10 September 2017 (UTC)

Oxygen TFA

I'm planning to rerun oxygen as WP:TFA on 5 September. It's deteriorate since it was promoted, so I cleaned it up, removed refs from lead section (now frowned upon) replaced a dead reference, removed a dead EL and generally tried to tidy it up for TFA. I removed a number of unsourced or inappropriately sourced statements, since it's effectively impossible to run an article at TFA with uncited text. If anyone can further tidy the article before it runs, that would be great. Most of the unsourced material I have no reason to believe to be incorrect, so if it can be supported by FA level refs, obviously it can be added back. My edits. Thanks, Jimfbleak - talk to me? 06:17, 21 August 2017 (UTC)

Thank you! I have reinstated some of the unsourced material that I could easily find a citation for. Double sharp (talk) 06:31, 21 August 2017 (UTC)

Oxygen scheduled for TFA

This is to let you know that the oxygen article has been scheduled as today's featured article for September 5, 2017. Please check the article needs no amendments. If you're interested in editing the main page text, you're welcome to do so at Wikipedia:Today's featured article/September 5, 2017, but note that a coordinator will trim the lead to around 1100 characters anyway, so you aren't obliged to do so. Thanks! Jimfbleak - talk to me? 08:04, 23 August 2017 (UTC)

New WikiProject: WP:Periodic table category colors (PTCC)

I have started a new WP project: WP:Periodic table category colors (WP:PTCC). It is to be the central place to develop category colors.

For example, current issues with PTCC are:

1. New colors for new categories ("corrosive nonmetals").
2. Bad contrast for AM and TM (alkaline metals and transition metals)
3. The PT colors need a new set (10+1 categories), keeping good design in mind.
4. Since our PT images (templates, images, facts) are re-used all over interwiki, we should keep that usage in mind (iw-wikis often use our image blindly, trusting us. Could be bad info in the end).

Question: please take a look at Help:PTCC (improve content). This page is the goto-page for other wikis, I suggest (describing our PTCC best).

-DePiep (talk) 22:15, 25 August 2017 (UTC)

Oh, and see User:DePiep/PTCC. -DePiep (talk) 22:16, 25 August 2017 (UTC)

Predicted metallicity colors

What would be the consequences of eliminating the predicted metallicity colors and simply using the unknown gray. It would significantly simplify the selection of a color palate. Where are they predicted colors used? Does someone know offhand, or perhaps someone knows how to search? They aren't used in any of the graphics in the main periodic table article. YBG (talk) 18:11, 26 August 2017 (UTC)

When redesigning the category colors, this is irrelevant (or must be made irrelevant). A category set requires 10+unk legend colors, an almost impossible task. Then add that they must comply with w3c contrast rules, and colorblindness guidances, it is clear that the degrees of freedom are contradicting (not a satisfying solution possible). Then to add the 'predicted colors' request is pushing it off the cliff. So in WP:PTCC, the predicted categories are second or third rate requirements. (For example, should/could be solved graphically otherwise). -DePiep (talk) 00:45, 27 August 2017 (UTC)

My hope is that the answer to my questions will reveal that predicted colors are unnecessary. I know that still leaves a hugely overconstrained set of requirements, but IMO every bit helps. YBG (talk) 03:53, 27 August 2017 (UTC)

Actually I rather agree with YBG. The predicted chemistry of the elements past 120 is so complicated that declining to assign a category may be the best bet; the familiar chemistry you learn from hydrogen to oganesson will no longer help you, although this may disappoint some "periodic table fans". I would perhaps suggest solid grey for "unknown chemical properties" and solid white (or transparent) for "we haven't discovered the element". Double sharp (talk) 04:07, 27 August 2017 (UTC)

Agree. Sandbh (talk) 04:45, 27 August 2017 (UTC)

So there is a sound scientific reasoning to abandon mentioning "predicted" this way (coming from long-time involved editors). That could conclude "Remove named category colors for predicted" (without changing the textual mentioning in the infoboxes etc I assume?). With this, the coloring issue is moot (gone).

Next: add a color for "undiscovered" as opposed to "unk chemical properties".

Prior question(!): is "unknown chemical properties" correct wording, or should "physical" be included? E.g., saying "Unknown properties" better?

Then, a new color ("Undiscovered") being white is a bit difficult for unbordered cells (such as the micro PT in the infobox). We could use the "unknown properties" grey just as well (for now). Will look for a new color. -DePiep (talk) 11:05, 27 August 2017 (UTC)

I think Double sharp's comment to use "solid white (or transparent) for 'we haven't discovered the element'" is a way of saying that if there is not yet a claim for discovery, there would be no cell shown on the periodic table. Until someone claims discovery of Z > 120, we probably don't need to worry about this. YBG (talk) 18:00, 1 September 2017 (UTC)

Well, for the extended periodic tables, I would suggest that the atomic number alone be included, with a border but no cell colour. Double sharp (talk) 05:00, 2 September 2017 (UTC)

Talk:Meitnerium#Bond distances predictions

The author of a cited paper reported a mistake in this article, please give a look. --Nemo 10:24, 29 August 2017 (UTC)

Implementing the recoloring of group 12

Now that the RfC has been closed and the change accepted at § Proposal: Colour group 12 as post-transition metals, how do we go about implementing it? Is this something that can be done piecemeal over time or would it be better to perfect a complete list of the necessary changes and then make them more-or-less all-at-once? YBG (talk) 17:33, 1 September 2017 (UTC)

I'd say go ahead. Please mention in the editsummary: "RfC on group 12", e.g.

[[:en:Wikipedia_talk:WikiProject_Elements#Proposal:_Colour_group_12_as_post-transition_metals|RfC on Group 12]]

When text changes, best to check the whole article (or section, subtopic) for the change.

Templates: list of Periodic table templates (and images). For Images, please add in Commons: [[Category:Periodic table by enwiki-2013 categories]] for future ease (when actually used in our articles).

-DePiep (talk) 07:13, 2 September 2017 (UTC)

Done (most of) the template tables. That's the easy part, texts to do. Please add something like "RfC on group 12 colors" to the editsummary, to prevent double checking. -DePiep (talk) 09:30, 8 September 2017 (UTC)

I didn't see your post earlier, so I edited some texts without including the edit summary: I'll include it from now on. Double sharp (talk) 10:12, 8 September 2017 (UTC)

IUPAC

I just had a careful read of the IUPAC Red Book 2005, and was surprised to see that "transition metals" is not an IUPAC-approved collective name.

All that the Red Book says is:

Optionally, the letters s, p, d and f may be used to distinguish different blocks of elements. For example, the elements of groups 3–12 are the d-block elements. These elements are also commonly referred to as the transition elements, though the elements of group 12 are not always included…

The Gold Book on the other hand says that a transition element is, "An element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell." The Gold Book cites The Red Book 1990 as its source, which is two editions out of date; later Red Books were published in 2000, and 2005. The Gold Book entry is therefore (apparently) without foundation.

According to the Red Book, the only IUPAC-approved collective names are: alkali metals, alkaline earth metals, pnictogens, chalcogens, halogens, noble gases, lanthanoids, and actinoids. Sandbh (talk) 06:15, 3 September 2017 (UTC)

Side track: should we (at WP) rediscuss "lanthanoids" vs "lanthanides" (Ln) then? -DePiep (talk) 07:37, 3 September 2017 (UTC)

So IUPAC does not say "transition metals", but they do say "transition elements" right? What would be the issue then? All transition elements are metals, no problem. (Same with "rare earth elements" and "rare earth metals", see above). -DePiep (talk) 07:45, 3 September 2017 (UTC)

The trouble is that in some cases (Mt, Ds, and Rg), we have not actually done the chemical experiments needed to establish them as metals (or anything else really). So while they are transition elements by definition, whether they are transition metals is yet unknown (though no one seriously doubts it). Double sharp (talk) 05:06, 5 September 2017 (UTC)

What about changing our category name to "transition elements"? Granted, that only hides the issue, since they would still be in our supercategory of metals. But it would be nice to use the exact term used by the IUPAC. YBG (talk) 05:53, 5 September 2017 (UTC)

1. Double sharp just said that they are not confirmed to be metals. So they should not be in supercategory "metals" then? 2. How are they transition "by definition"? Isn't that by properties? We just did establish group 12 being transitions this way. -DePiep (talk) 06:33, 5 September 2017 (UTC)

3. Does IUPAC define "metals" at all anywhere? -DePiep (talk) 06:34, 5 September 2017 (UTC)

Regarding (1), they are indeed not under the "metals" supercategory in our table, but rather in the "unknown chemical properties" one. On (2), the definition given by IUPAC is simply "groups 3-11 or groups 3-12"; so Mt, Ds, and Rg are assigned to groups 9, 10, and 11 respectively and so must literally be considered transition elements by this definition. (Of course, the reason for the definition lies in the properties the elements in these groups share, but that's not what is explicitly stated.) On (3), the IUPAC Gold Book appears to lack an entry on "Metal". This state of affairs is not particularly surprising, although it is surely disappointing. We can take some comfort in that this is not at all localised to chemistry: for quite some time now Grove's Dictionary of Music has similarly lacked an entry on "Music". Double sharp (talk) 06:58, 5 September 2017 (UTC)

As I get it, the main issue is not IUPAC red book definition, but our categorisation as "metal" (as in "transition metal") when not proven to be a metal. Meanwhile, all are proven to be transitional (i.e., the correct part of categorisation names). -DePiep (talk) 09:32, 8 September 2017 (UTC)

Yes, that's absolutely right. Double sharp (talk) 10:11, 8 September 2017 (UTC)

Sorry, it seems that my suggestion has created a bit of a tempest in a teapot. Using "transition metal" provides consistency between our category names, but using "transition element" provides consistency with IUPAC. Not sure which consistency is a foolish hobgoblin and which isn't. So IMO it really is a bit of "two 15s make one 30" or "six of one, half a dozen of the other" -- at least until such time as someone demonstrates the existence of a transition nonmetal. And if that were to occur, we've got even bigger categorization fish to fry. YBG (talk) 16:51, 8 September 2017 (UTC)

TFA reruns

Recently it was decided that because of insufficient new FAs, older FAs could be rerun at Today's featured article after five years have elapsed. A provisional list is in preparation of important articles that could be rerun, and Oxygen is today's TFA. There are other elements on the list, Helium, Hydrogen and Uranium, but they have problems such as dead links or uncited text. Is there any chance of these being licked into shape to give them a chance of running again? Jimfbleak - talk to me? 05:50, 5 September 2017 (UTC)

Well, we have enough old FAs that I suspect that we could, as soon as we actually decided on which one we were going to run! ^_^ H and He seem to be excellent ideas to me; I will try to look through and cite anything I can find the source for quickly on a first pass. Double sharp (talk) 06:49, 5 September 2017 (UTC)

The Wikipedia:WikiProject Elements/TrophyBox has 29 FA articles now. Cannot reach WP:PETSCAN now, but I'd like to cross-check that list with Category:Featured articles that have appeared on the main page (7,287). Jimfbleak -DePiep (talk) 08:17, 6 September 2017 (UTC)

• See Category:FA-Class chemical elements articles (29) (not: 1 FL, 1 FT).

PetScan says: all articles have been TFA (unless my petscan is wrong...). -DePiep (talk) 09:52, 8 September 2017 (UTC)

Proposal: Replace categories of poly/diatomic nonmetal with less active/active nonmetal

Preliminary notes

These notes could be addressed beforehand, and should not become not part of the RfC

-- Sandbh (talk) 03:35, 9 September 2017 (UTC) -- @Sandbh: I have added text to the last paragraph under "What the new scheme would look like" and added some hidden comments, both in that paragraph and in two other places. The hidden comments (all marked with "- YBG") can be removed once you have considered them. The added text can be modified or reverted entirely if you wish. You may also feel free to remove this paragraph as a part of polishing up your proposal into an RfC. YBG (talk) 04:22, 9 September 2017 (UTC) -- I've also tweaked the table at the beginning to add the previous halogen / other NM categorization; I think this helps provide context. But given this, it might be better to reverse the order of the table rows. I'll leave that decision up to others. And if you think this confuses things, then by all means revert my edit. YBG (talk) 04:35, 9 September 2017 (UTC)

Thank you! Will review. Sandbh (talk) 05:54, 9 September 2017 (UTC)

• Sandbh, in File:Periodic Table Chart with less active and active nonmetals.png, could you color group 12 into grey #CCCCCC? -DePiep (talk) 08:54, 9 September 2017 (UTC)

Done. It shows in the draft nonmetal article but not when you click on the image, which is strange. Sandbh (talk) 00:16, 10 September 2017 (UTC)

@Sandbh: More importantly, could you do it for our current PT welcome mat File:Periodic_Table_Chart.png? ^_^ Double sharp (talk) 14:08, 9 September 2017 (UTC)

Not needed: I've asked that at The Graphics Lab. (So Sandbh can spend time on other things ;-) ). -DePiep (talk) 15:05, 9 September 2017 (UTC)

Thank you! Sandbh (talk) 00:16, 10 September 2017 (UTC)

Help-page for Periodic tables on interwiki

The enwiki periodic table pages are copied into other multiple wikis, sometimes blindly. That is including the enwiki choices such as group 3 composition (scientific) and categorycolors (editorial). Because of continuing changes in the enwiki settings (like the group 12 recoloring), those wikis may show outdated or even incorrect periodic tables. To stimulate correct spreading I have started page Help:Periodic table classifications in the English Wikipedia. It gives an overview of these enwiki choices & changes. For the commons PT images, there is c:Category:Periodic tables using the enwiki classifications.

Feel invited to improve this iw-targeted documentation. -DePiep (talk) 13:12, 9 September 2017 (UTC)

RfC: Replace categories of poly/diatomic nonmetal with less active/active nonmetal

I am seeking comments on a proposal to change part of the current nonmetal categorisation scheme, as follows:

From	Polyatomic nonmetal C, P, S, Se	Diatomic nonmetal H, N, O, F, Cl, Br, I
To	Less active nonmetal H, C, N, P, S, Se	Active nonmetal O, F, Cl, Br, I

Origin
The origin of this proposal can be traced to literature conceptions of nonmetals as either halogens (F, Cl, Br, I, At), noble gases, or other metals (H, C, N, O, P, S, Se), with the last of these three groupings representing a poorly characterised "orphan" or leftovers category.

The Wikipedia periodic table used to show the three categories of halogens, noble gases, and other nonmetals up until mid-2013 when we recategorised astatine as a metalloid. Astatine has been predicted to have a metallic crystalline structure, which suggests there may be grounds to categorise it as a post-transition metal. But condensed astatine has not yet been observed so for the moment is left as a metalloid.

When astatine was recategorised as metalloid the opportunity was taken to get rid of the nondescript "other nonmetal" category name by moving C, P, S, and Se into a new polyatomic nonmetal category, and moving H, N, and O, into a new diatomic nonmetal category, along with F, Cl, Br, and I. We got rid of the term other nonmetal since it wasn't based on any consideration of the shared attributes that should characterise a useful category name. And it's an awkward term to use if you want to say something like, for example, "nonmetals form compounds with metals and other nonmetals" or "like hydrogen, carbon forms molecular covalent compounds with most other nonmetals."

You can see the use of the current polyatomic and diatomic arrangement, which is based on structural considerations, in the nonmetal article. It works, but I've never been completely satisfied with it since it does not necessarily show the most relevant trends associated with nonmetallic character. Chemists tend to think of nonmetals primarily in terms of such things as oxidative power, electronegativity, activity, reactivity, anionic behaviour, or electron affinity, rather than whether the nonmetals have polyatomic or diatomic molecular structures.

Proposal
In retrospect I think it would better to categorise H, C, N, P, S, and Se as less active nonmetals, and O, F, Cl, Br, and I as active nonmetals. Such a division would be based on multiple electrochemical properties, rather than a single structural consideration.

In this arrangement, O, F, Cl, Br, and I are individually and collectively characterised by relatively high ionisation energies, high electronegativities, high electron affinities, high oxidising power, and simple anion formation, consistent with their depiction in the literature.

H, C, N, P, S and Se are unable to consistently match the active nonmetals across the aforementioned electrochemical properties.

The proposed category names, which end with the form "-ive", can accommodate the fact that, for example, while the overall tendency of H and S is to act as reducing agents, they are sometimes capable of acting as oxidants. Another example would be the fact that nitrogen has a higher electronegativity than bromine and iodine. Now nitrogen does show some "active" character in its capacity to form hydrogen bonds and complexes, but it is a poor oxidising agent unless combined with an active nonmetal like O or F; and it is a reluctant anion former, unlike the active nonmetals. So, at the broadbush level being dealt with here, N is a less active nonmetal, with some "active" nuances if you dig deeper. This is consistent with the meaning of the "-ive" suffix: "that performs or tends toward or serves to accomplish an indicated action esp. regularly or lastingly" or "having a tendency to, having the nature, character, or quality of, given to (some action)". Hence it has the meaning of a tendency rather than a finality.

On the question of boundary overlaps such as these I turn also to Jones (2010, pp. 169–171):

"Though classification is an essential feature of all branches of science, there are always hard cases at the boundaries. The boundary of a class is rarely sharp…Scientists should not lose sleep over the hard cases. As long as a classification system is beneficial to economy of description, to structuring knowledge and to our understanding, and hard cases constitute a small minority, then keep it. If the system becomes less than useful, then scrap it and replace it with a system based on different shared characteristics."

Similar overlaps occur elsewhere in the periodic table. For example, beryllium in group 2, an alkaline earth metal, behaves chemically more like aluminium in group 3, a post-transition metal; the group 3 transition metals scandium, yttrium, lanthanum and actinium behave largely like the alkaline earth metals or, more generally, s block metals; and gallium in group 13, tin in group 14, and bismuth in group 15, all of which are post-transition metals, have some metalloid properties.

The periodic table nevertheless retains its status as an organising icon of chemistry.

Formative discussions
The proposal is a culmination of around six months of discussion with members of WikiProject Elements. We concluded that these two categories subdivided the eleven non-noble nonmetals in a manner that would be more consistent with differences in nonmetallic character. The only other recategorization that received a significant amount of discussion was placing all eleven nonmetals in a single category but this categorization obscured significant differences within the eleven. Having agreed on the categorization, much of our discussion revolved around determining the best category names. We considered but discarded a range of alternative paired category names, including: weak/strong; intermediate/corrosive; reactive/corrosive; reductive/oxidative; covalent/ionic; heterogenic/corrosive; foundation/corrosive; formative/corrosive; and less active/corrosive.

What does IUPAC say?
IUPAC does not provide any guidance on category names for the nonmetals. They have endorsed use of the terms "noble gases" and "halogens" however these are group names rather than category names such as post-transition metal, and metalloid, neither of which are IUPAC endorsed. We do show the group names in our larger periodic table, but we don't have a halogen colour category since we count astatine as a metalloid, which has a different colour category.

What does the literature say?
As it turns out, there is support in the literature for the terms "less active nonmetal", and "active nonmetal". Here are some quotes that use this terminology and highlight the distinctiveness of O, F, Cl, Br, and I.

• "A salt is a compound of metal ions and nonmetal ions. The halogens being active nonmetals are excellent salt-formers." (Allen et al. 1942, p. 484)
• "What, in general, is the difference between active metals, less active metals, less active non-metals, active non-metals, and inert gases…?" (Friedenberg 1946, p. 230)
• "The halogens and oxygen are the most active non-metals." (Lee & Van Orden 1965, p. 197)
• "The most active non-metals are in the upper right-hand corner of the chart; the most active metals are in the lower left-hand corner." (Luder 1965, p. 39)
• "From Group V on, the series passes from the less active nonmetals to the most active ones, like chlorine, in Group Vll." (Gardiner & Flemister 1967, p. 22)
• "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 1968, p. 234)
• "If you don't count the noble gases, Family 18, the most active non-metals are found in the upper right corner." (Aldridge 1993, p. 175)
• "Active nonmetals, such as the halogens (Group VIIA) and oxygen, are good oxidizing agents." (Grolier Incorporated 1999, p. 162)
• "Oxygen is one of the most active nonmetals and one of the most important. It forms compounds with all the elements except the light noble gases (He, Ne, and Ar). In general, oxygen forms ionic compounds with metals…" (Hill and Petrucci 1999, p. 903)

What the new scheme would look like
A draft rewrite of the nonmetal article using the proposed descriptive category names of less active nonmetal and active nonmetal can be found here.

The proposed scheme would result in a more balanced distribution of nonmetals, from 4 + 7, to 6 + 5.

Summary
I propose to replace the diatomic and polyatomic nonmetal categories with the newly constituted categories of less active nonmetal, and active nonmetal, as sourced from the literature. These categories are more consistent with the most relevant trends associated with nonmetallic character.

References

• Aldridge B et al. 1993, Science interactions, Glencoe/McGraw-Hill, New York
• Allen JS, French SJ, Woodruff JG 1942, Atoms, rocks and galaxies: a survey in physical science, Harper and Brothers, New York
  
• Beiser A 1968, Perspectives of modern physics, McGraw-Hill, New York
• 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
• Gardiner MS & Flemister SC 1967, The principles of general biology, Macmillan, New York
• Grollier Incorporated 1999, The encyclopaedia Americana, vol. 21, Danbury, Connecticut
• Hill JW & Petrucci RH 1999, General chemistry: An integrated approach, Prentice Hall, Upper Saddle River, New Jersey
• Jones BW 2010, Pluto: Sentinel of the outer Solar System, Cambridge University Press, Cambridge
• Lee GL & Van Orden HO 1965, General chemistry: Inorganic and organic, 2nd ed., Saunders, Philadelphia
• Luder WF 1965, General chemistry, Saunders, Philadelphia

— Sandbh (talk) 23:30, 9 September 2017 (UTC)

Survey

Indicate Support or Oppose below.

1. oppose on the basis of defining hard categories may be counterproductive as you said there are no hard divides. Also oppose on the basis IUPAC gives no guidance on this suggesting classification like this is not useful. EvilxFish (talk) 11:17, 10 September 2017 (UTC)
   • Though I would note that the current polyatomic/diatomic divide is not given by IUPAC either; following their (lack of) classification in the region would lead to not splitting the nonmetals at all. Which is not a bad choice either. ^_^ Double sharp (talk) 11:57, 10 September 2017 (UTC)
2. If IUPAC fails, ignore them We considered not splitting the non-noble nonmetals at an earlier stage; they would then be called chemically active nonmetals. However, the literature presented above makes clear that the distinction we propose is useful in understanding the chemistry of the nonmetals. I myself support. Parcly Taxel 12:53, 10 September 2017 (UTC)
3. Support. I am particularly pleased and convinced by the main rewritten nonmetal article (sandbox). -DePiep (talk) 15:30, 10 September 2017 (UTC)
4. Support, after some long consideration over the months. Of all the possible divisions, this seems to reflect what is going on the best and accord with as many properties of the elements in question as it seems possible. Double sharp (talk) 15:34, 10 September 2017 (UTC)
5. Oppose. Sorry I haven't been active lately (and I won't be for quite a while), but I feel I have to comment on this one. I haven't been watching the discussion, so please write if I am missing something. But also have in mind that if I don't see it from my first look, chances are, many others won't, either.

First of all, by no means am I a fan of the current poly-/diatomic divide. I think allotropy is a very poor reason for a general classification.

That being said, I think "active nonmetals" is a poor term. Precisely, it is poor because the word "active", by its very nature, is a relative quality. "Polyatomic" and "diatomic", as inappropriate for a general classification as they are, are unambigous (or close to that, but hardly will anyone not understand that the standard conditions are meant, and unusual cases like high pressure were not considered): it's either two atoms in one molecule of the free substance or more (or a non-molecular sturcture). That's a clear divide. Both terms are clear by themselves. What's an "active" nonmetal, though? How active does it have to be to count as "active"? Can you define this term without looking at other elements? Even worse, what's a "less active" one? I easily see the noble gases being counted as those "less active" nonmetals.

Imagine the infobox for P, for example. It says, "less active nonmetal." This phrase is asking for a "less active than what?" So the term is not just unclear, but also incomplete.

While I am eager to be proven wrong, I continue to think that there is no good divide at all. I see myself agreeing on a divide with two clear self-descriptive relevant terms, but throughout all of this time, we haven't found a single one. This particular divide does not highlight anything, even anything as irrelevant as allotropy; it is a divide for the sake of having a divide.--R8R (talk) 17:36, 10 September 2017 (UTC)

See re #R8R below. -DePiep (talk) 18:28, 10 September 2017 (UTC)

1. Oppose While some nonmetals may sometimes be described being more active than others, it is not useful to divide the nonmetals into "more active" and "less active" ones for a couple reasons.

1. How "active" an element is is can be defined in numerous different ways, so it's a rather vague attribute.

2. Even with a clear definition of how "active" an element is, there's still no clear divide seperating the more active elements from the less active ones, so classifing dividing them that way is rather subjective. For example I wouldn't consider iodine to be a particularly active element or sulfur to be a particularly inactive element. OrganoMetallurgy (talk) 19:57, 10 September 2017 (UTC)

Discussion

• Practical question: when does a survey thread be moved/continued into this Discussion section? (Example in case: first Survey by EvilxFish 11:17, 10 September 2017). -DePiep (talk) 14:50, 10 September 2017 (UTC)
• @EvilxFish: [4]

Your claim it being "counterproductive" is too strong. Sure a hard category is preferable (like with the noble gases), but absence of it does not invalidate categorisation. The "productive" point of categorisation is: it shows a trend in the periodic table. Yes for example nitrogen is doubtful in here (could be argued to be an active nonmetal), but that does not invalidate the trend. More in general, the periodic table is filled with such doubts in detail, or even contradictions. However, by looking at the grand tableau the trends show useful information about periodic grouping and behaviour. After all, it was Mendeleev who started ignoring local problems (atomic weight order did not match —then unknown— atomic number order, so he just boldly flipped tellurium and iodine to make them fitting, correctly in hindsight; don't try this at home on wiki), thereby solving the magnificent scheme quest. So, when hard borders are missing, we can endeavour in soft borders. It is no secret that IUPAC is not the forerunner in this, nor is expected to be that. This being Wikipedia, Sandbh has done a great job in exploring literature on this, and painting a great picture with this fine-haired broad brush. -DePiep (talk) 15:17, 10 September 2017 (UTC)

• @R8R: [5]

In short: it is the periodic table. Look for the PT trend, not the border issues. Poly/diatomic property is both correct, and ~useless.

Yes, the P infobox will say less active nonmetal — but wikilinked! That's still better than "other nonmetal", which would win your point. btw, I'd say the noble gasses are "not active". -DePiep (talk) 18:27, 10 September 2017 (UTC)

"Look for the PT trend, not the border issues." The beauty is in the eye of a beholder. You could easily distinguish the early transition metals (groups 3, 4, 5) from the late ones (groups 8 onward) and call it a part of a PT trend (which it is). Or you can say that the s-block is, trend-wise-speaking, one category. That being said, there are many ways to look at "the trend." It also appears to me that you are mixing the debate on whether we should have 1 or 2 categories for non-noble nonmetals and if should (in the latter case) go for "poly-/diatomic" vs. "active/less active."

It's interesting that this wikilink only redirects to Nonmetal. Perhaps one day this could be fixed, though, granted. Nevertheless, we here are facing a categorization problem and it should be no wonder that if a category name must have a meaning on its own: that's how you (should) categorize. This is a critical flaw I'm pointing at. (Also, of course, "other nonmetal" would never pass this.) So the current (weak) scheme is better than the suggested one, which I am genuinely sorry to say.--R8R (talk) 19:55, 10 September 2017 (UTC)

Infobox element: Spectral lines images

1. I have created the overview list {{Spectral lines of the elements}}, now live in spectral line. It uses {{Infobox element/symbol-to-spectral-lines-image}} (with some 30 image names at first).

2. {{Infobox element}} now reads the image name from that list (so, not added as a parameter into {{Infobox aluminium}} any more). Also, it shows in header "Physical data", not as a second image. (|image 2= is deprecated and does not show any more). Example: helium. When no image is in the list, nothing shows (vanadium).

• Considerations. Some months ago we discussed removal of these spectral images. That did not take off. However, my then argument that this image is not important enough to be the second image in top, still stands (per WP:INFOBOX). Also, recently the parameter standard atomic weight was moved up into General properties because atomic weight is "so important it must be close to the top", "the fundamental importance". This implies that other properties must be less important, and should be moved downward. Plus, of course, that it is impossible to put everything in top.

• Maintenance. {{Infobox element/symbol-to-spectral-lines-image}} now has some 30 images (26 were in the infoboxes). The list could be expanded by searching commons c:Category:Atomic spectra. I think it's best to use the "visible" images (=in the visible spectrum only) when available.

In the table {{Spectral lines of the elements}}, it shows that not all images have the same ratio (w:h). They could be cropped I guess.

Maybe the showing in the infobox needs tweaking (position within Physics section, size, ...). Ideas? -DePiep (talk) 14:21, 10 September 2017 (UTC)

 Done added all available images up to & including E99 Es. Missing: At, Fr. Same name pattern "Einsteinium spectrum visible.png", same source (creator), so all ratios are equal. -DePiep (talk) 16:03, 10 September 2017 (UTC)