Talk:List of aqueous ions by element/Archive 1

Archive 1

Atlas of Pourbaix diagrams

Bearing in mind some caveats needed about species that "should" be unstable but stick around a long time because of unfavourable kinetics: this might be of use. Double sharp (talk) 08:53, 29 July 2021 (UTC)

Note that many different Pourbaix diagrams are included for the elements, and they sometimes differ. The anionic species LnO₂⁻ are present in alkaline solution (pH 14 will do, apparently) according to only one of them. So, we can discuss if this sort of thing should be in or not. I've held off on adding stuff for the 4d and 5d metals because there is some significant disagreement on what the species actually are. Probably oligonuclear species are often simplified in that atlas.

I added the hydrolysed alkaline earth metal species from here, because it seems every one of the databases they used agrees on the existence of these species. (Except radium where it can be chalked up to radioactivity). Beyond that, I stuck to just adding some things from the actinoids (mostly the most logical hydrolysed species), since there I can again believe some differences coming from them being a bit difficult to study. Thereafter, maybe some care should be taken. Double sharp (talk) 04:26, 7 August 2021 (UTC)

@Sandbh and Petergans: What are your views on this? Double sharp (talk) 04:37, 7 August 2021 (UTC)

@Double sharp and Petergans: I can find support for the alkaline earth oxocations in Brown & Ekberg [1], chapter 7, even for radium, noting their stability goes down as ionic radius increases.

In their chapter on the rare earths they write:

"There is no reliable evidence that even higher monomeric species form and in a study of the solubility of Nd(OH)3(s), Neck et al. (2009) found no evidence of increased solubility at high pH which would have indicated the formation of Nd(OH)4−. Thus, it is accepted that Ln(OH)4− does not form for any of the lanthanide metals; similarly, the species Y(OH)4− will not form for yttrium." (p. 250)

For the Geological Survey of Japan source, this writes, "It should be noted that this open file report presents the Eh-pH diagrams calculated from databases ”as is”, without any critical comments." (p. 7)

On this basis I wouldn't include Y and lanthanide oxoanions. Sandbh (talk) 06:54, 7 August 2021 (UTC)

@Sandbh: Thanks, indeed that accorded with my intuition. ;) I'd decided to leave only the extra species for group 2 and actinoids (where for Ac–Cm I could believe that some radioactivity issues arose). So, unless there's an objection, everything seems fine except that Ac and Cm should turn orange. :) Double sharp (talk) 04:06, 9 August 2021 (UTC)

Done for Ac and Cm. Sandbh (talk) 04:17, 9 August 2021 (UTC)

@Sandbh, Petergans, and Double sharp: It looks to me like there are no outstanding issues in this section and it is ready to be archived. Please correct me if I am wrong; otherwise, I plan to archive it in a few days. Please let me know if it should not be. YBG (talk) 22:34, 22 August 2021 (UTC)

Good to go. Sandbh (talk) 06:00, 26 August 2021 (UTC)

Richens: The Chemistry of Aqua ions

Will be hard work; there are no summary tables. About 600 pp.

For the main group elements he does not deal with C, N, P, O, Po, At, Rn. Further, no predominance digrams are given. Sandbh (talk) 05:04, 29 July 2021 (UTC)

Good work! The table now looks credible, though there might still be niggles with elements that have ions in many oxidation states. I hope that Richens has information for the heavier actinides. Petergans (talk) 08:29, 29 July 2021 (UTC)

Alas, he does not. He stops at plutonium.

However, there has been some pretty recent work on those elements. E.g. 2013 study for mendelevium. So we know there are some species, the reduction potentials between them, and their charges. Unfortunately, we don't yet know the hydration number and structure.

As for transactinoids, it is not well-known (doi:10.1007/978-94-007-0211-0_14). Rf and Db have only been studied in the presence of complexing anions. Sg has been studied in 0.1 M nitric acid media; it seems to hydrolyse less readily than W, so probably the formed species is Sg(OH)₄(H₂O)₂²⁺ or SgO(OH)₃(H₂O)₂²⁺, although that's not really a concrete identification. Bh has no information. HsO₄ appears to react with NaOH similarly to OsO₄, so probably forms an anionic species [HsO₄(OH)₂]²⁻. And that's all we have. Double sharp (talk) 08:48, 29 July 2021 (UTC)

@Sandbh, Petergans, and Double sharp: It looks to me like there are no outstanding issues in this section and it is ready to be archived. Please correct me if I am wrong; otherwise, I plan to archive it in a few days. YBG (talk) 22:30, 22 August 2021 (UTC)

Good to archive. Sandbh (talk) 05:59, 26 August 2021 (UTC)

Plea number n for non-coordinating anions

Because this is precisely how all those elusive cations like Mo³⁺ got evaluated in the first place.

Parish, The Metallic Elements, 1977 (I think it's p. 133):

Study of the aquo-, hydroxo-, and oxo-complexes (Table 5.8) of the 4d- and 5d-metals is complicated by two factors. Firstly, when the metals are in relatively low oxidation states a great many ligands, including most simple anions, are able to displace water from the coordination sphere. In order to avoid hydrolysis it is usually necessary to work with acidic solutions, so that an excess of anions is present. The metal is usually found in anionic complexes which may or may not contain coordinated water, or hydroxo- or oxo-groups. Consequently, most redox-potential data refer to complexes rather than to aquated species, and the values vary with the anion present. In a few cases special care has been taken to use acids whose anions coordinate very weakly (ClO⁻
₄, NO⁻
₃), and simple aquated cations have been observed for Mo³⁺, Ru²⁺, Ru³⁺, Rh³⁺, Pd²⁺, Ag⁺, Au³⁺, Cd²⁺, and Hg²⁺. Rhodium(II) and mercury(I) form binuclear aquated cations, Rh⁴⁺
₂ and Hg²⁺
₂. The second complicating factor is that, for the higher oxidation states in alkaline solution, polymeric species are formed which coexist over wide pH-ranges in complex series of slowly-attained equilibria. It is difficult to establish the nature of the species present and, as discussed on pp. 77–8, the species which can be isolated in solid salts may bear no relation to those present in solution.

Note also the relevance to Petergans' comment on polyoxometallate anions.

What this is on about is that the measures used in this list to exclude Pt²⁺ would be sufficient to exclude many 4d species that are included without comment. The only routes to them equally involve using non-coordinating anions. Logic seems to imply that they should either all be included, or all be excluded. If the latter course of action is chosen, then I think they should be at least put into footnotes. Double sharp (talk) 09:45, 28 July 2021 (UTC)

Thanks Double sharp, and Petergans. I've provisionally added ions for Ta, Os, and Pt, subject to confirmation of their stability. Image and table updated. Sandbh (talk) 07:50, 29 July 2021 (UTC)

@Petergans, Double sharp, and Sandbh: Have these issues been dealt with? Is this section ready to be archived? YBG (talk) 22:27, 22 August 2021 (UTC)

Yes. Yes. Sandbh (talk) 05:56, 26 August 2021 (UTC)

editing clashes

I'm working on a general revision of the column "oxyanions" (in my sandbox), so please do not edit the data in that column. I intend to

remove all species resulting from protonation of oxyanions. Explanation in the intro...

The formula HXO_m^n- are pretty meaningless for polymeric species. Label all empirical formulae with ^† or remove? Note that there is always ambiguity between hydroxo, oxo and mixed complexes with formulae written in this way.

very many missing species: include dimers of oxyanions but only link to higher polymers.

show different oxidation states on different rows.

move anions such as HS^- to correct column.

Also

emphasize that there is information on many species in the element's WP article and in general textbooks such as Greenwood and Earnshaw. Change links, where possible, to article sections.

replace notes at both top and bottom of the table by text at the top, where possible.

Petergans (talk) 09:53, 31 July 2021 (UTC)

HS− has been moved to the anion column. Sandbh (talk) 04:37, 1 August 2021 (UTC)

@Sandbh and Petergans: It looks to me like there are no outstanding issues in this section and it is ready to be archived. Please correct me if I am wrong; otherwise, I plan to archive it in a few days. Please let me know if it should not be. YBG (talk) 22:35, 22 August 2021 (UTC)

Good to go. Sandbh (talk) 06:01, 26 August 2021 (UTC)

Hafnium

Richens p. 218 indicates that the Hf^IV species should be written as Hf₄(OH)₈⁸⁺, analogous to Zr^IV (as one would expect). Double sharp (talk) 07:43, 1 August 2021 (UTC)

Very good. So added, and Zr fixed too. Sandbh (talk) 08:36, 1 August 2021 (UTC)

@Sandbh and Double sharp: It looks to me like there are no outstanding issues in this section and it is ready to be archived. I plan to archive it in a few days unless someone tells me it should not be. YBG (talk) 22:39, 22 August 2021 (UTC)

Good to go. Sandbh (talk) 06:03, 26 August 2021 (UTC)

Sorting

 Resolved YBG (talk) 17:40, 21 August 2021 (UTC)

It is no longer possible to sort the table so that the combinations sort together. This is a very useful feature, providing an easy way to see how many of elements have each sort of coloring in the periodic table. YBG (talk) 05:10, 4 August 2021 (UTC)

@YBG: Any thoughts on how to restore this functionality, and the rest of the columns, with the least amount of work? I'm ready to help if that'd help. Sandbh (talk) 06:26, 4 August 2021 (UTC)

The sort option is purely cosmetic and serves no practical purpose. Articles like polyoxometalate provide details concerning particular categories. Petergans (talk) 09:05, 4 August 2021 (UTC)

I like it for being able to see the numbers of elements in each category. Sandbh (talk) 11:44, 4 August 2021 (UTC)

I also note that the Z column has been removed, making it impossible to resort the table back to its original order. And because that column and the symbol column are missing, the correspondence between the list and the periodic table is intelligible only to the chemically knowledgeable. These should definitely be restored before nominating this as a featured list.

I can probably restore these things relatively easily by copying the wikitext into MS-Word, converting it to a table, transforming the data, and converting it back again. But I hesitate to do that if it is only going to get removed again.

I also think that the species combo column should include a graphic that corresponds to the graphic symbols used in the PT, about which see my comment in the next section.

YBG (talk) 23:28, 5 August 2021 (UTC)

YBG, Could you please go ahead. I'll revert if it gets removed again. Sandbh (talk) 23:38, 5 August 2021 (UTC)

Any thoughts on what I should use for abbreviations in the combinations column? YBG (talk) 23:49, 5 August 2021 (UTC)

 Done I decided to use the same C/xC/A/xA that had been in the table before; the 'x' works equally well for 'oxy-' and 'hydroxy-'. YBG (talk) 00:43, 6 August 2021 (UTC)

@Petergans and Sandbh: It looks to me like there are no outstanding issues in this section and it is ready to be archived. I plan to archive it in a few days unless someone tells me it should not be. YBG (talk) 22:42, 22 August 2021 (UTC)

This one is gtg. Sandbh (talk) 06:05, 26 August 2021 (UTC)

Oxo- vs oxy-

Just wondering what the difference is between oxycations and oxocations or between oxyanions and oxoanions. Are the terms synonymous? Is there a difference? Which forms should be considered the common name? YBG (talk) 01:48, 8 August 2021 (UTC)

They're synonymous. Google Ngam shows oxycation as being more popular than oxocation. Oxyanion is way more popular than oxoanion.

Here are the hits from the ACS journals database: oxocation 94; oxycation 109; oxoanion 1222; oxyanion 6838. Hydroxo- is 9088; hydroxy- 145231.

Could you please change the article name to "List of aqua-ions and their hydroxy- and oxy- derivatives in aqueous solution", plus update the rest of the terminology?

Sandbh (talk) 02:22, 8 August 2021 (UTC)

That answers my concern. I was thinking that we should either move the oxyanion and oxycation articles or else change the terminology in this article.

More questions: Are hydroxyanions a type of oxyanions? Are hydroxycations a type of cations?

YBG (talk) 04:44, 8 August 2021 (UTC)

Yes they are AFAIK. Sandbh (talk) 07:44, 8 August 2021 (UTC)

This is a question of the application of current IUPAC rules on nomenclature. -oxy was used pretty much universally in the "old days". Petergans (talk) 08:25, 8 August 2021 (UTC)

We’re more or less obliged to reflect common usage rather than, in this case, whatever the IUPAC nomenclature rules are. I see there are articles on oxycation and oxyanion rather than oxocation and oxoanion. The ngram and ACS metrics are decisive IMO. Sandbh (talk) 11:38, 8 August 2021 (UTC)

OK, now that I understand that they are synonymous, I will follow WP:COMMONNAME as reflected in the articles oxyanion and oxycation. If at some point there is a consensus to move those articles, then the usage in this article should be changed to match. YBG (talk) 21:35, 8 August 2021 (UTC)

 Resolved and ready to be archived. @Sandbh and Petergans: please let me know if you disagree. YBG (talk) 23:08, 22 August 2021 (UTC)

Time to archive. Sandbh (talk) 06:09, 26 August 2021 (UTC)

Some comments & suggestions

@Sandbh:, some thoughts about the structure of this article, in separate subsections for the illustration and the text. YBG (talk) 03:45, 20 July 2021 (UTC) ​ Thank you YBG.

The article illustration

1. There are many inconsistencies in the generic cell borders. Borders internal to the table are always shown, unless there is no higher-order boundary being indicated. Borders on the external edges are generally not shown, but inconsistently are shown for elements 1, 2, and 72-86. Removing all external borders makes H and He even uglier IMO. A better solution would be to replace the generic border with a white border, perhaps wider than the current one; this would not clash with other borders you are trying to show, e.g., the unexplained dashed line that is I think the boundary between metals and nonmetals.

   I've tidied up some of the lines, and added a note about the cationic-anionic boundary. My aspirational philosophy about lines is to only show as many as are needed and no more. Sandbh (talk) 00:45, 21 July 2021 (UTC)

   It may be a subjective matter, but my eye sees the lines as cell boundaries, not cell dividers. I understand (but strongly disagree with) your perspective that the lines are dividers not boundaries and so should only be placed where absolutely needed. The reasonable compromise would be to use wider white dividing lines, This would IMO accommodate readers with either perspective. YBG (talk) 04:16, 22 July 2021 (UTC)

   On minimising lines, I take guidance from Edward Tufte's book, The visual display of quantitative information. The spreadsheet has been sent, as promised. Looking forward to seeing the results. A compromise will be fine, subject to the way it looks. 03:17, 24 July 2021 (UTC)

   Could you please cite the place in Tufte's book that you are relying on? A page number is sufficient; I think I've got copies of his book in my cube at work, and I have to go in sometime in the next few weeks for a couple of hours, the third time since last March. YBG (talk) 05:06, 24 July 2021 (UTC)

   ​His removal of "Chartjunk" philosphy pervades his book and its numerous examples, including B4 and after. Sandbh (talk) 04:46, 25 July 2021 (UTC)

   Thank you for explaining the dashed line. But it seems to me that 41,43,74,77 are on the wrong side of the line. Am I missing something? YBG (talk) 04:16, 22 July 2021 (UTC)

    Needs discussion Please respond (a) to suggestion about cell boundaries and (b) to question about 41,43,74,77. YBG (talk) 06:11, 23 July 2021 (UTC)

   They are indeed now on the wrong side of the line. I've added dashed lines around them. Sandbh (talk) 03:17, 24 July 2021 (UTC)

   Well, now it is accurate ... but confusing and cluttered, and it calls into question the appropriateness of the line. When the line divided the table into two diagonally, it was helpful. But as you are fond of saying, nature isn't always neat. In this case, I think the dashed dividing line isn't really very helpful. IMO the table would be better off without it. YBG (talk) 05:06, 24 July 2021 (UTC)

   ​They remain important IMO given the metals and nonmetals meet in the p block, where interesting things happen. Further, the fact that four d-block metals form only oyxanions is of interest from the pov of discussing chemistry-based criteria for defining a metal. User:Double sharp and I have discussed phenomenon at some length. Sandbh (talk) 04:46, 25 July 2021 (UTC)

2. Speaking of those other boundaries, are they really relevant to the subject of this table? If not, leave them out.

   Removed. Sandbh (talk) 00:45, 21 July 2021 (UTC)

    Resolved Ta YBG

3. "Nil" would be better replaced by "None" or something more explanatory.

   Replaced with "no such species" Sandbh (talk) 00:45, 21 July 2021 (UTC)

    Resolved Ta YBG

4. The blocks and the group names do not seem to be directly related to the purpose of this table - as evidenced by the fact that there is no mention of them in the article. Consequently adding this superfluous information distract the reader from the theme of this table. Removing these would eliminate several uglinesses in the table - the group numbers jumping up and down; the confusing situation of He's block (nb, shouldn't one use "His" for the possessive form of "He" :); the use of non-standard group names; and the unexplained use of the abbreviation "PGM".

   Done Sandbh (talk) 00:45, 21 July 2021 (UTC)

   Thank you for removing the block label, it makes it much cleaner. But the group numbers, which IMO are unnecessary, now unfortunately appear in two locations. YBG (talk) 04:16, 22 July 2021 (UTC)

    Needs discussion Please respond to remaining concern about group numbers. YBG (talk) 06:11, 23 July 2021 (UTC)

   Removed. Sandbh (talk) 03:17, 24 July 2021 (UTC)

   Looks like you removed some but not all of the group numbers. Was that your intention? YBG (talk) 05:15, 24 July 2021 (UTC)

   ​Removed. Sandbh (talk) 04:46, 25 July 2021 (UTC)

5. The footnote connection would be better served if the Z-range were included in addition to the terms "Lanthanides" and "Actinides". Even better would be to remove those terms entirely since they like the group names distract the reader from the purpose of this table.

   Done Sandbh (talk) 00:45, 21 July 2021 (UTC)

   I had in mind that the number range would be repeated, but this is OK. Might me nice to have parentheses around the Z ranges. YBG (talk) 04:16, 22 July 2021 (UTC)

    Needs discussion Please try (a) adding parens, (2) using italic, and/or (3) repeating Z-range. If none seem better, I'll take your word for it. YBG (talk) 06:11, 23 July 2021 (UTC)

   Parentheses added.

    Resolved YBG (talk) 05:06, 24 July 2021 (UTC)

6. ₂₃V is shown with two colors, the lower left half indicating "Cations and oxyanions" and the upper right indicating "Oxyanions". Wouldn't the former be sufficient?

   My error; V = cations, oxycations & anions Sandbh (talk) 00:45, 21 July 2021 (UTC)

    Resolved YBG (talk) 06:11, 23 July 2021 (UTC)

7. ₈₅At also has two colors: "Cations & oxycations" and "Anions & oxyanxious"; perhaps this deserves a separate entry in the legend.

   At is correctly shaded; all four species are present Sandbh (talk) 00:45, 21 July 2021 (UTC)

    Resolved YBG (talk) 06:11, 23 July 2021 (UTC)

8. The table uses the same device (colors) to indicate both individual ion species (cations, oxycations, anions, oxyanions) and also combinations (c+oc, a+oa, c+oa). This scheme hides information; it is not obvious, e.g., that ₃₆₂₆Fe, ₂₇Co, and ₄₅Rh all have cations, or that ₈₅At displays all four species.

   I thought that e.g. in the case of Fe, since it is coloured in red, that this denotes the presence of only cations in solution. You are right with regard to At; depending on pH and V, all four kinds of species are known. I'll add a note about the diagonal colours. Sandbh (talk) 00:45, 21 July 2021 (UTC)

   My point re Fe/Co/Rh is that they all have cations, but this commonality is totally hidden. YBG (talk) 04:16, 22 July 2021 (UTC)

    Needs discussion Do you see this as an issue? What solutions do you see? (besides what I suggest below). YBG (talk) 06:11, 23 July 2021 (UTC)

   • One possible solution would be to have a 4-part icon in the upper right of each cell. This icon could be a square with four quadrants or a 4-leaf clover with four leaves. An outlined white quadrant/leaf would indicate that the particular species is not present; outlined and filled, that the species is present, say, upper left yellow for a cation being present; lower left orange for an oxycation being present; upper right blue for an anion; lower right purple for an oxyanion; thus, left=*cation (yellow or orange); right=*anion (blue or purple); bottom=oxy*ion (orange or purple); top=non-oxy*ion (yellow or blue).

     I'll email you the spreadsheet so that, if you like, you could try this. Sandbh (talk) 00:45, 21 July 2021 (UTC)

     That would be nice. But no promises. YBG (talk) 04:16, 22 July 2021 (UTC)

     C Waiting to receive the spreadsheet. YBG (talk) 06:11, 23 July 2021 (UTC)

     Now sent. Sandbh (talk) 03:17, 24 July 2021 (UTC)

      Resolved And received. I would appreciate hearing your response to "Do you see this as an issue" just above. YBG (talk) 05:06, 24 July 2021 (UTC)

YBG (talk) 03:45, 20 July 2021 (UTC)

Additional notes:

• I is Z=53, not Z=83

  C Waiting to see the iodine atomic number fixed. YBG (talk) 06:11, 23 July 2021 (UTC)}}

   Resolved Fixed. Sandbh (talk) 03:17, 24 July 2021 (UTC) Ta YBG (talk) 05:06, 24 July 2021 (UTC)

• Why does ₁H have two different shades of yellow and a diagonal line? What species is this meant to represent?

   Needs discussion Please explain H to me. YBG (talk) 06:11, 23 July 2021 (UTC)

  Without the diagonal line H appears to be a metal. So, the downside is for [H(OH₂)_n ]⁺ and the upside is for OH^–. Sandbh (talk) 03:17, 24 July 2021 (UTC)

  Hmmm.... not sure I completely understand. Could you have a look at the table entry for
  ₁H and see if it is correct? YBG (talk) 05:06, 24 July 2021 (UTC)

  I've just seen Note A you added to the graphic. Presuming that a hydrated cation counts as a cation and not as an oxycation, this means that H has both a cation and an oxyanion and the table row is correct. Based on these ion species, it should be simply colored yellow the same as Al, Cr, Mn, Mo, Rh, Sn, Re, Bi, and Po. Your concern that this makes H appear like a metal is irrelevant. This is a table of "stable ion species in aqueous solutions", not a table of metals and nonmetals. Did add a special color to Nb, Tc, W and Ir so they wouldn't look like nonmetals? No, we colored them according to their ion species. We should do the same with hydrogen.

YBG (talk) 04:16, 22 July 2021 (UTC)

​Quite so. Dashed line for H repositioned. Sandbh (talk) 04:46, 25 July 2021 (UTC)

I have tried to clearly mark the status of all these items. YBG (talk) 06:11, 23 July 2021 (UTC)

The questions are now numbered since the hashmarks become problematic when inserting responses. Sandbh (talk) 03:17, 24 July 2021 (UTC)

The hashmarks have been restored (as I did previously). They are not problematic if you will include them in your response, e.g., instead of typing ::, simply type #:: and voila, the software takes care of everything and the diff is sooooo much easier to follow. It is a very small thing, but your cooperation in this would be much appreciated. YBG (talk) 03:42, 24 July 2021 (UTC)

​Thanks; will do. Sandbh (talk) 04:46, 25 July 2021 (UTC)

I have now restored the hash marks and bullets.

• special:diff/1035022304/1035174374 Before your edit to after my cleanup, neatly showing your added comments and the addition of bold and removal of some stray curly brackets.
• special:diff/1035168654/1035174374 Diff of the cleanup Changes I made after your edit.
• special:diff/1035168654 Diff of your edit, which is much more difficult to follow than either of the other two diffs.

Figuring out how to properly nest the line indentation markers #, *, and : took me a while to figure out, but once I did it made things much easier. Now I will go back look at the content of your responses, for which I am very grateful. YBG (talk) 04:32, 24 July 2021 (UTC)

Most everything has been resolved and so marked; here is a summary of the points I'd still like to hear from you:

• (#1) Page reference in Tufte's book
• (#1) Wondering whether the now more complex dashed dividing line is helpful or not.
• (#4) Some group numbers still remain, "2" above
  ₄Be and "3" thru "12" above
  ₂₁Sc and following.
• (#8) Wondering your thoughts about the encoding system hiding the commonality of elements that all have cations but happen to have different other species.
• (2nd • ) Asking you to verify the
  ₁H row to help me understand how you colored that cell.

  Per my note above, H should be colored according to the species of ions it forms in aqueous solution; there is no need for a diagonal line.YBG (talk) 06:02, 24 July 2021 (UTC)

Feel free to respond here or above, but if you do respond above, kindly include hash marks on your responses to retain the numbering and indenting. YBG (talk) 05:06, 24 July 2021 (UTC)

​All addressed hopefully, bar #8. That one to follow. Sandbh (talk) 04:46, 25 July 2021 (UTC)

The article text

Resolved I believe these are all now resolved YBG (talk) 05:20, 23 July 2021 (UTC)

The second sentence would be better expressed as an exclusions from the list; many list articles define their scope in this way. I will take a stab at doing this. Good Sandbh 00:45, 21 July 2021 (UTC) Well, I tried to make this change, but you reverted it. I think there should be an explicit statement that begins something like "Not included in this chart are ....". The present wording is hard to understand, especially for someone like me who isn't entirely sure what is meant by "species" and "agent" and whether these might be two names for the same thing or two entirely different things. And does "are present" mean "present in the solution" or "listed in this periodic table"? YBG 06:00, 22 July 2021 (UTC) I tried again; if it is not accurate please work to improve it rather than reverting to the former form. YBG (talk) 14:23, 22 July 2021 (UTC) It seems IMO that some wikilinked mention of the four species would be helpful. I may try doing this, but I'm less certain. OK Sandbh 00:45, 21 July 2021 (UTC) I considered making this change, but I don't think I am competent to do it, so could you please try? In this context, I note that an oxyanion is a type of anion, and an oxycation is a type of oxycation, but in the context of this article, "cation" means "cation that is not an oxycation" and "anion" means "anion that is not an oxyanion". This should be explained someplace. YBG 06:00, 22 July 2021 (UTC) I've added what I believe is an accurate wording, please help improve it if necessary. YBG (talk) 14:23, 22 July 2021 (UTC) There is one reference attached to the end of the second sentence, and a half dozen bibliography entries. I don't have access to any of them, but it seems like they are all of the same sort. Why aren't they all listed as references at the end of the sole paragraph? Other than the one that mentions 85At in its name, do some others just support a handful of elements? If so, it might be good to list the applicable elements in the footnote. Done Sandbh 00:45, 21 July 2021 (UTC) Thank you, it is much better now. I do wonder whether the astatine-specific reference belongs at the end of the lede paragraph or in the note re At. YBG 06:00, 22 July 2021 (UTC) I made several changes to the notes: (1) Add Z+Sym to each note (2) Use more typical bulleted format w/o hr (3) Make At the subject of its note's 1st sentence (4) wikilink elements. If you disagree with some of these, please only revert what you disagree with instead of the entire edit. Then initiate a discussion here about the disputed changes. YBG 06:00, 22 July 2021 (UTC) I think it would be better to order the notes by Z now that it is included in the note. But I did not make this change because it would have made the diff very difficult to follow. YBG 06:00, 22 July 2021 (UTC) Now that I've added a list, the notes are automagically sorted by Z. YBG (talk) 15:45, 22 July 2021 (UTC) This is a very weird article in that the actual content is not in the article itself but in an illustration? I'm pretty sure I have never run across another article like this in all of my random wanderings in WP. I've repositioned the image and made it larger Sandbh 00:45, 21 July 2021 (UTC) Looks much better now. But my point remains: it is weird for an illustration to actually contain the bulk of an article's information rather than merely illustrating the information in the text of the article. YBG 06:00, 22 July 2021 (UTC) Now that there is a list, this article doesn't seem to be the outlier that it was before. YBG (talk) 16:01, 22 July 2021 (UTC) Here/s a suggestion: Rename the article "List of stable ion species in aqueous chemistry" and then include a sortable table in the body of the article. Doing this would have several useful features: (1) now the illustration is truly an illustration and not the content; (2) Some references can be applied to the header of a column (eg, if they cover just anions or oxycations), while others can be applied to row (eg, the reference to 85At). Suggested table columns: Col 1-3: Z, Symbol, Element name Col 4-7: Anion, Oxyanion, Cation, Oxyanion: Each column either blank or containing the word as the column heading. Shaded according to the color used in the 4-part icon. Col 8: Species: A comma-separated list of the contents Col 4-7, or else simply the 4-part icon used in the table. Necessary in order to allow sorting by the combination and not merely by the individual species. If an icon is used, probably better to put this column before the previous four. Col 9: Reference: Any references that apply to a single element or to a small handful of elements YBG (talk) 03:45, 20 July 2021 (UTC) OK, that's something I'll look at later. Sandbh (talk) 00:45, 21 July 2021 (UTC) I've actually started working on such an list table; if I get it to a point that I'm happy with it, I'll add it to the article. YBG 06:00, 22 July 2021 (UTC) I've added this table, and suggest that the article be moved to List of ions in aqueous chemistry or List of stable ions in aqueous chemistry. YBG (talk) 15:45, 22 July 2021 (UTC) The table entries could actually be changed from the species name to the actual ion. YBG (talk) 16:00, 22 July 2021 (UTC) I've added a bunch of comments above along with time-stamping your original replies. Hopefully, I've avoided spamming you with a huge number of pings like my last edit did. YBG (talk) 06:00, 22 July 2021 (UTC)

@Sandbh and Double sharp: I have made some extensive additions to lede paragraph, and consider all of the article-text issues collapsed above to be closed . Here are the remaining issues I see in the article text, table, and references:

1. I think the sources might be better placed somewhere in the header or title of the table rather than at the end of the lede paragraph.

   ​ Probably doensn't matter so much either way. Sandbh (talk) 06:17, 25 July 2021 (UTC)

2. I wonder whether the Liu reference (Exploration of astatine chemistry in solution) belongs in the astatine-specific note rather than a general reference.

   That's fine. Sandbh (talk) 06:17, 25 July 2021 (UTC)

3. Speaking of At, the caveats listed in the note make me wonder if the sources really give us enough to qualify these ions as existing in purely aqueous solution. It might be good to remove them from the list and rephrase the note to be more like
   ₇₃Ta,
   ₇₆Os and
   ₈₆Rn.

   Keep. There has been a fair amount of research attempting to clarify the aqueous chemistry of At and Liu's work represents a good contemporary summary. Sandbh (talk) 06:17, 25 July 2021 (UTC)

4. I wonder whether the Vernon reference (Which elements are metalloids?) is on point. It immediately follows a quote from Kirby, which is certainly better attested to by the Kirby citation.

   It includes some further commentary as to uncertanties about the aqueous chemistry and has been cited by other authors writing on the radiochemistry of At.

5. My extensive rewording of the "lede" would benefit from copyediting.

   Done. Sandbh (talk) 06:17, 25 July 2021 (UTC)

6. It would be great if the formula for each species of each element were inserted into the table.

   To follow. Sandbh (talk) 06:17, 25 July 2021 (UTC)

7. This article is badly in need of some inbound links.

Thank you for your review. YBG (talk) 05:20, 23 July 2021 (UTC)

Thanks YBG. Sandbh (talk) 06:17, 25 July 2021 (UTC)

YBG, a link has been added in Aqueous solution. A link was added to Metal ions in aqueous solution twice, and removed twice by the lead editor of that article. A "See also" has been added to this article. Sandbh (talk) 07:38, 26 July 2021 (UTC)

Ready to archive? (1)

I think this is ready to archive. All issues mentioned have been dealt with except for the question of lines around elements in the periodic table, which is dealt with in #Mini-RFC 1: Cell borders. If there are no further comments in this section I plan to archive the section. YBG (talk) 22:21, 22 August 2021 (UTC)

Indeed it is. Sandbh (talk) 06:14, 26 August 2021 (UTC)

Thallium oxyanions?

I'm not sure what to make of this one:

• Bashilova NI & Khomutova TV 1984, "Thallates of alkali metals and monovalent thallium formed in aqueous solutions of their hydroxides", Bulletin of the Academy of Sciences of the USSR Division of Chemical Science, 33(8), 1543–1547, doi:10.1007/bf00959177.

It's suggestive of thallium oxyanions in solution yet not definitive. Sandbh (talk) 08:36, 1 August 2021 (UTC)

FWIW, Richens p. 150 notes:

Due to the high acidity constant K₁₁, Tl³⁺ (aq) is only stable in strongly acidic solution. Mononuclear hydrolysis products TlOH²⁺ (aq) and Tl(OH)₂⁺ (aq) appear to be the only forms relevant prior to precipitation of the hydrous Tl₂O₃ around pH 1.

So at the very least Tl should be coloured as forming oxycations as well. Double sharp (talk) 11:45, 1 August 2021 (UTC)

Only the in the presence of perchlorate. Since Tl forms cations all by itself in water, the presence of perchlorate seems too far off a level playing field, unlike the PGM where a reasonable case can be made. Sandbh (talk) 13:41, 1 August 2021 (UTC)

Perchlorate is a non-coordinating anion, and Richens mentions it at the top of the page where he discusses Tl³⁺. So, by that logic, we should remove Tl³⁺ as well, which you have there. Whereas it seems obvious that the perchlorate is just a means to an end to get the cation easily into aqueous solution without affecting the coordination situation much.

It seems more of a level playing field to allow such non-coordinating anions in for everybody, rather than just for noble metals. Molybdenum requires them too, per Richens. :)

P.S. Note that Tl₂O₃ is insoluble in water. :) Double sharp (talk) 14:11, 1 August 2021 (UTC)

I'll remove Tl³⁺ since TlOH is quite soluble. S & P (p. 167) say the former is highly unstable and persists only in very strong acid (hence perchlorate) and readily gives over to Tl₂O₃. 219.90.178.191 (talk) 00:59, 2 August 2021 (UTC)

Yes, this is also reasonable. :) Double sharp (talk) 02:48, 2 August 2021 (UTC)

Curiously, Rayner-Canham, in the Periodic Table: Past, Present, Future, (p. 167) shows TlO−(aq) in very basic solution! News to me; no indication of a source. Sandbh (talk) 07:43, 6 August 2021 (UTC)

There's also TlO₂⁻ here. Double sharp (talk) 14:27, 6 August 2021 (UTC)

Excellent find!

See also:

https://www.osti.gov/servlets/purl/1035958: TlO₂⁻

Nanomaterials for Environmental Protection: same

https://srd.nist.gov/jpcrdreprint/1.555839.pdf (p. 12): TlO⁻
₄

I'll add at least TlO₂⁻, and ask Rayner-Canham about TlO−(aq). I'll remove Tl³⁺
since S & P (p. 167) say this is "highly" unstable in aqueous solution. Sandbh (talk) 01:45, 7 August 2021 (UTC)

@Sandbh and Double sharp: It looks to me like there are no outstanding issues in this section and it is ready to be archived. I plan to archive it in a few days unless someone tells me it should not be. YBG (talk) 22:40, 22 August 2021 (UTC)

Good to go. Sandbh (talk) 06:03, 26 August 2021 (UTC)

Noble gases

There are some known Rn(VI) species. In acidic aqueous solutions (pH > 5), both cationic [HRnO₃]⁺ and anionic [HRnO₄]⁻ are produced. Pretty analogous to xenon trioxide, as one would expect. (Evidence is from electromigration, had been confirmed using the xenon analogues. See also doi:10.1016/S0898-8838(08)60149-X.)

Also, why has xenon been removed from known species? Xenates and perxenates are known in solution. Double sharp (talk) 09:45, 29 July 2021 (UTC)

I didn't have access to the publications. Petergans (talk) 10:02, 29 July 2021 (UTC)

This first article is cited by Holloway & Hope, which is the last cite provided by Double sharp. They say (p. 93), "Recent electromigration studies have also been used to suggest that in acidic aqueous solutions (pH > 5) cationic, [HRnO3]+,and anionic, [HRnO4]−, forms of radon are produced, the validity of the electromigration method having been established using xenon(VI) (244)." The latter cite = Avrorin, V. V.; Krasikova, R. N.; Nefedov, V. D.; Toropova, M. A. Radiokhimiya 1989, 31, (6), 63.

H&H also say:

• (p. 65), "The addition of alkali to XeO3 solutions yields…[HXeO4]−. Although salts of this species can be isolated, solutions containing [HXeO4]− disproportionate to give…[XeO6]4−, and xenon…".
• (p. 68) The transient green coloration observed in the early days of noble-gas chemistry was identified in 1978 as being due to the dixenon cation (103, 104). The cation can be produced either by oxidation of gaseous xenon using [O2]+ or by reduction of [XeF]+ with water or other reducing agents such as lead or mercury. The green species is stable in SbF5 indefinitely at room temperature under an atmosphere of xenon gas (103-105).

[XeO6]4− looks worthy of inclusion. The dixenon cation probably not since it exists in superacid territory. Nitrogen oxycations are around in that realm too.

What is the opinion on the radon species? It'd be good to know a bit more about their stability. Sandbh (talk) 01:08, 30 July 2021 (UTC)

I do not know any more recent work on this. Although I'm not surprised given the short half-life of radon. Greenwood in a millenium perspective doi:10.1039/B103917M cites Holloway and Hope, but still calls them "less certain". Maybe worthy of a footnote. Double sharp (talk) 04:17, 30 July 2021 (UTC)

Thanks, I've included the Rn species since there is no basis to doubt the Russian source, which appears in a peer-reviewed journal, it has been cited elsewhere, and the findings are not surprising based on periodic trends. It make the dashed line look interesting, too. Sandbh (talk) 04:00, 31 July 2021 (UTC)

Well, I suppose Greenwood's doubt could have been based on Stein's, mentioned in Holloway and Hope. But it was answered by Avrorin et al.:

Claims by Russian workers that a higher fluoride of radon, RnF₄ or RnF₆, can be prepared in tracer experiments by heating radon, xenon, fluorine, bromine pentafluoride, and either sodium fluoride or nickel fluoride, and converted to RnO₃ by hydrolysis (240) appeared to others [Stein] (235) to be due to the precipitation of radon as a solid complex, which is probably [RnF]₂⁺[NiF₆]²⁻. However, the precipitation of CsXeO₃F from aqueous solutions results in the coprecipitation of radon, and this has been taken by the Russian group as confirmation that RnO₃ is the product of hydrolysis of the fluoride formed (241). Furthermore, it has been suggested that the failure of Stein to observe the high-oxidation-state [RnO₃F]⁻ species was probably due to high F⁻ concentration (242). More recently, ultracentrifugation of hydrolyzed radon solutions, coprecipitation studies, and kinetic data for the decomposition of the solution species have been interpreted in terms of it being RnO₃ (243). Recent electromigration studies have also been used to suggest that in acidic aqueous solutions (pH > 5) cationic, [HRnO₃]⁺,and anionic, [HRnO₄]⁻, forms of radon are produced, the validity of the electromigration method having been established using xenon(VI) (244).

Double sharp (talk) 07:51, 1 August 2021 (UTC)

@Sandbh: Shouldn't radon be split light orange/green instead of light orange/blue? The negatively-charged species it forms contains oxygen. :) Double sharp (talk) 02:52, 2 August 2021 (UTC)

@Double sharp: Quite so. Thanks! Now changed. Sandbh (talk) 04:53, 2 August 2021 (UTC)

@Sandbh, Petergans, and Double sharp: It looks to me like there are no outstanding issues in this section and it is ready to be archived. Please correct me if I am wrong; otherwise, I plan to archive it in a few days. Please let me know if it should not be. YBG (talk) 22:34, 22 August 2021 (UTC)

Good to go. Sandbh (talk) 06:00, 26 August 2021 (UTC)

Krypton

 Resolved YBG (talk) 17:39, 21 August 2021 (UTC)

Are we so sure about krypton oxoacids? I was under the impression one had been reported and then never reproduced. Pretty sure the original paper describes preparing it from KrF₄, which turned out to be a misidentification of KrF₂. Double sharp (talk) 03:22, 6 August 2021 (UTC)

No such thing. It's gone. Sandbh (talk) 06:06, 6 August 2021 (UTC)

Found the original kryptic acid paper, FWIW. Double sharp (talk) 06:20, 6 August 2021 (UTC)

Duplicate references

All duplicates have been consolidated except for refs 12 and 20 (Vernon!). Petergans (talk) 20:03, 6 August 2021 (UTC)

Uranium

 Resolved YBG (talk) 22:43, 22 August 2021 (UTC)

There seem to be some anionic species in basic solution (p. 267 has the Pourbaix diagram). There was already an entry reading "uranates" in that column, so I added "xA". Double sharp (talk) 14:27, 6 August 2021 (UTC)

Thanks! Updated. Sandbh (talk) 03:53, 7 August 2021 (UTC)

Major upgrade to image box fill colours

 Resolved YBG (talk) 22:45, 22 August 2021 (UTC)

Now done, following much good work by Peter in updating the table of ions. Sandbh (talk) 03:52, 7 August 2021 (UTC)

Major revision (2)

The table contained many inaccuracies, errors and omissions, so a major revision was needed. I have gone through the table element by element, using mainly the books by Baes & Mesmer and Richens.

• Each oxidation state is now shown on a separate row.
• Many highly polymeric species are not included because the published stoichiometry is not firmly established.
• Anionic species such as HS^- have been removed as they don't belong in this table.
• Uncharged species that can exist in solution, such as Pu(OH)₃, are still not included in the table.
• Colours of transition metal ions have been removed as colour will depend on the extent of hydrolysis.

I apologise if any recent contributions by other editors have been removed as a consequence of the long time that was needed for this thorough revision. Petergans (talk) 21:51, 15 August 2021 (UTC)

​Peter, what happened to the cations eg. Na⁺ and anions e.g Cl⁻? Sandbh (talk) 02:07, 16 August 2021 (UTC)

Common knowledge! Columns 1 and 2 of the table serve no purpose as the elements are listed in atomic number order. Do you agree that they should be removed? Petergans (talk) 08:54, 16 August 2021 (UTC)

As currently set up, they only serve as identification. However, if the table were repaired so that sorting again worked, the atomic number column would be very useful to restore the table back to its original order. This can be accomplished in one of two ways:

• (1) retaining separate rows but using |rowspan= in the first few columns in the first row and omitting them in the subsequent rows; or
• (2) putting everything again in one row, with {{hr}} to divide the different oxidation numbers.

Does anyone have a preference as to which of these should be used? YBG (talk) 03:02, 17 August 2021 (UTC)

Y I have implemented (2) in the article. YBG (talk) 07:33, 17 August 2021 (UTC)

​​Dear Peter, thank you very much for all your work associated with the major revision. I do hope you'll retain an ongoing interest in the further development of this list.

The list should probably retain columns 1 and 2. Column 1 for sortability, as YBG has written elsewhere. Column 2 to maintain a connection with the periodic table image, which semi-relies on element symbols. The notes column needs to be reinstated at least for citations supporting the listed species for each element.

Each oxidation state doesn't need to be on a separate row. Oxidation states can instead be used to inform the order of the species in the same row.

I don't understand why anionic species such as HS⁻ don't belong in this table, given the scope of the article is stable ions in aqueous solution.

On colours of transition metal ions there is an abundance of reliable sources speaking to what these are. If the colour'll depend on the extent of hydrolysis, that's something that can be discussed in the explanatory text accompanying the list, rather than being thrown out with the bathwater.

The cations and anions formed by each element may be common knowledge for chemists, however wp lists and articles are aimed at general readers, for whom this'll not be common knowledge. Nor would I expect some chemists to be familiar with e.g. the controversy surrounding the existence of S²⁻
; or the cationic or anionic species (aq) of e.g. Po and At. Sandbh (talk) 05:35, 17 August 2021 (UTC)

Regarding colors and the oxidation numbers: I like both of these features, but IMHO it will be hard to include both of them. I lean slightly toward including the colors as I think it would make the article more interesting to the general reader, adding to the "zing" started in the lede picture. But I do not hold this view strongly, and am happy with an consensus reached by discussion as opposed to mere bold editing.

Whole books have been written about colour in chemistry. The capacity of transition metals to form coloured ions in solution, in contrast to most representative elements, is one of their key distinguishing features. Sandbh (talk) 08:03, 17 August 2021 (UTC)

Regarding simple cations and simple anions: I agree that it would be better to include these due to the target audience being the general reader.

Regarding species characterised with a high degree of certainty: This is IMO the greatest improvement presented in the major revision. My preference would be to only include species whose experimental verification is well-attested ideally in tertiary sources (or multiple secondary sources), thus excluding those appearing in primary sources or only inferred theoretically. This of course excludes many of the superheavy elements not available in macroscopic quantities.

YBG (talk) 06:08, 17 August 2021 (UTC)

Follow-on changes necessary

1. Sorting needs to be repaired in the table (see note above)

    Done YBG (talk) 05:48, 17 August 2021 (UTC)

2. The lede section needs to be revised to correspond to the scope change introduced by the major revision

    Partly done YBG (talk) 05:48, 17 August 2021 (UTC)

3. The introductory paragraphs preceding the table needs to be drastically cut. I think all of the information is needed, but all but the important points should be moved to notes.

   Perhaps not since FL's can have a fair amount of introductory text e.g. List of presidents of the University of Illinois system Sandbh (talk) 05:35, 17 August 2021 (UTC)

   That is a good example. Please note that in § List of presidents there is no text at all between the section header and the table. That is what I was wishing to drastically reduce. I have reduced it somewhat by moving much of the text into the lede section, but I'm afraid I might have destroyed some of the coherence. YBG (talk) 05:48, 17 August 2021 (UTC)

   Should be fine; can be developed as required. Sandbh (talk) 06:48, 17 August 2021 (UTC)

4. The periodic table section needs to be revised
5. The elimination of anion and cation columns needs to be ratified by consensus.

   I intend to restore these two columns. Sandbh (talk) 05:35, 17 August 2021 (UTC)

   @Sandbh: Please wait until there is actually some discussion before doing that. 06:08, 17 August 2021 (UTC)

   @YBG: No need, given the title of the article. Cations and anions are aqueous ions. Recall the article was created with cations, oxycations, anions, and oxyanions. There was no justification for their removal. I'd revert except it'll be more productive to transfer Peter's corrects into the old table, just before he boldly overwrote it. There will thus effectively be a BRD sequence. Sandbh (talk) 06:39, 17 August 2021 (UTC)

(#1-#5 added by YBG (talk) 03:10, 17 August 2021 (UTC))

• I am missing the oxidation number (column) [2]. As it shows now, it is a "find it out yourself". See e.g., P, V. -DePiep (talk) 16:03, 17 August 2021 (UTC)

Revert

@YBG and Petergans: As flagged I've effectively reverted Petergans table, pursuant to WP:BRD, and incorporated nearly all of his changes into the immediately older table. I didn't incorporate his changes to Po, At, Np and Pu. I provided citations for At, Np, and Pu. For Po, these species are readily discerned from the literature, AFAIR. Sandbh (talk) 07:55, 17 August 2021 (UTC)

@Sandbh: Except for what you've mentioned, are all of the oxy*ions the same as what Petergans included? Are all of the elements well attested in secondary or ideally tertiary sources? YBG (talk) 09:03, 17 August 2021 (UTC)

@YBG: Yes. Yes. Sources are listed in the Books section, and in the notes column, and the latter were checked, where applicable, to see they had been cited by other sources. See also discussion elsewhere on this page, mainly between DS and myself. Sandbh (talk) 12:42, 17 August 2021 (UTC)

@Petergans, YBG, and Double sharp: Peter, in reverting my revert on the grounds there was no consensus is not consistent with WP:BRD. You boldly overwrote the older table, without attempting to seek consensus, as you were entitled to do. I reverted, as I was entitled to do. Per WP:BRD, discussion now follows in attempt to seek consensus I trust things can now proceed in a WP:CIVIL manner. Sandbh (talk) 12:36, 17 August 2021 (UTC)

Ping-pong reversion is not an acceptable way to deal with this issue. We should move forward, not backward. If consensus cannot be reached, then a compromise must be agreed.

Regarding oxidation states, the baby has been thrown out with the bathwater. Petergans (talk) 13:10, 17 August 2021 (UTC)

I think the best way forward is (1) Undo @Sandbh:'s revert, thus restoring @Petergans:' version with the {{chem2}} changes; and then (2) Add the missing columns to that version.

This is what I anticipated that Sandbh was going to do when he stated his intention to restore the cation and anion columns. Had I known this was an announcement of what amounts to a revert, I would have spoken more strongly against it in hopes of encouraging a more collaborative working environment. Yes, one can look at Sandbh's actions as within the spirit of WP:BRD, though not within the letter, as it was not a simple revert. So it is equally possible to say that Sandbh's action was the bold, which would make Petergans' action the revert. This is one of the problems with BRD I have seen over the years, there is frequently the potential of ambiguity in assigning edits to the "B" and "D". This is perhaps one of the reason why BRD is merely an explanatory supplement and has not become a fully vetted policy.

What do people think of my planned approach above (1)+(2)? Not sure when I'd have time to do it, but when I find time, I will check back here to see what people have said. YBG (talk) 15:46, 17 August 2021 (UTC)

I'd prefer your proposed actions. I could not easily or clearly deduct what exactly Sandbh's objections to Peter's changes are. Not helped by the fact that multiple levels of edit were passed in one go, eg the Po ... Pu quartet altering and the "see elsewhere on this page" blanket arguing. -DePiep (talk) 15:52, 17 August 2021 (UTC)

Obviously I support the suggestion of a reversion+. Perhaps this is the time to state that my reasons for removing columns. It was that those columns contained nothing of substance that was not already included in the other columns of the the table. 1) Atomic number: the list is already in that order. 2) Element symbol: the element names already provide links to the element articles. 3) cation and anion species: very elementary information. 4) Summary of species: repetition of what is in the table. 5) anions: species such as HS^- are best considered as derived from the parent (H₂S in this case) by deprotonation. The anion is irrelevant in regard to hydrolysis. May I also add a personal opinion? There is no merit in allowing the table to be sortable. Petergans (talk) 22:09, 17 August 2021 (UTC)

@Petergans: The thrust of what you are saying is that certain things do not add information or functionality and so they add clutter to the table. I am sympathetic to the idea of eliminating clutter, but please keep in mind the intended consumer of this information: the general reader, perhaps the interested layman who vaguely remembers some things from secondary chemistry but has an interest that drives him to explore. For such a person, the anion and cation columns are not at all "elementary information", and the sorting capability facilitates exploration. If one posits that sorting is superfluous, then the atomic number column and the summary of species columns also become superfluous. If one assumes sufficient knowledge of chemistry to be able to predict the anion and/or cation columns, then those columns also become superfluous. But we assume a naive but curious audience, and hence, IMO, those columns are helpful. YBG (talk) 02:14, 18 August 2021 (UTC)

Allow me to disagree on this, YBG. Here, sorting is part of searching and discovering, and so by ID (say name, Z, OS) is helpful for everyone. OTOH, sorting by the four *ion columns does not add much information AFAIK. Technically we can remove sortbuttons by cell, but I've refrained because of this threaddy. Note that, to help page navigation, I have added anchors-by-symbol so one can link to #He and § He. -DePiep (talk) 15:41, 18 August 2021 (UTC)

@DePiep:, re sorting, you are not disagreeing with me but agreeing. I said the sorting capability facilitates exploration. I added If one posits that sorting is superfluous, (as Petergans apparently does but DePiep and YBG do not) then the atomic number column and the summary of species columns also become superfluous.. (emphasis added) So I think we agree on this point. YBG (talk) 04:50, 19 August 2021 (UTC)

Thanks, solved. -DePiep (talk) 05:16, 19 August 2021 (UTC)

As for sorting the four species columns, I think there is some merit to sorting those columns, it groups the element into two groups, those with a particular species (anion/cation/oxyanion/oxycation) and those without; this sorting cannot be done by the summary-of-species column. I see no sensible way to order the elements within those two binary groups. The current quasi-random order is certainly no better than any other order and likely no worse. The value in sorting by these columns is relatively small so I wouldn't be too disappointed if they became unsortable. YBG (talk) 04:50, 19 August 2021 (UTC)

Revert (2)

@Sandbh, Petergans, Double sharp, and DePiep: OK, my big changes are done; here's what I did:

1. Reverted to one of the more recent versions with Petergans' form
2. Restored the missing information - anions, cations, notes, summary, colors
3. Added some (but not all) previously missing oxidation states
4. Applied a few edits that had occurred after the revert point
5. Modified the lede section to be consistent with this scope
6. Combined the scope-limiting paragraphs and notes together (It still needs more editing; the end result of my multiple edits may well have mangled the sense of what Petergans originally had. Sigh.)
7. Combined the Z, name & symbol columns together (at the expense of sorting the elements alphabetically)

My attempt here is to take the oxy*ion information from Petergans' version and combine it with the information from the columns that that version lacked. The result is a wide table that is less pleasant to read in a narrow screen. We could gain a little more space by making the colors small or superscripted, but to make it any narrower we'd have to give up on either colors or oxidation numbers, and I'm not inclined to do either. YBG (talk) 06:18, 18 August 2021 (UTC)

I think the width can be improved, but better first flesh out its content (especially columns & their content).

Incidentally, I'd suggest to list the ions, per element, vertically within their cell (i.e. not comma-separated); looks much stronger to see differences in their molecule. See beryllium. -DePiep (talk) 15:09, 18 August 2021 (UTC)

Oops, would not look good with like cobalt: multiple 'OS' values (so has these hor lines). There, keep comma-separated would be OK for overview. -DePiep (talk) 15:15, 18 August 2021 (UTC)

On oxidation state value: wouldn't it be more illustrative to add all, and to add +/− everywhere? (sorting effects!) -DePiep (talk) 15:43, 18 August 2021 (UTC)

I just have made few dozen of trivial, technical or (IMO) improving edits to the table, skipping enforcing in any controversies (AFAIK). Revert when I made an ~error, or ask me, here, to revert myself. -DePiep (talk) 16:36, 18 August 2021 (UTC)

It appears that I made several errors in the oxidation state column. Could someone please proofread the table and make the adjustments as needed? Thanks, {{yo}Petergans}} for pointing this out. YBG (talk) 05:25, 19 August 2021 (UTC)

Table layout

This section is to put together some table-organising issues (that are now scattered on this page).

Table header

Recently, I have changed the tableheader (not the columns) to show two headers ('cationic', 'anionic'), and four subheaders (for the four specimen) [3]. To me, as a layman, this was the best description of these 2+4 items and their relationship (IMO better than that complicated sentence in the current lede).

However, YBG made this change, repositioning & rewording. I don't think this is an improvement (hope it does not have to do with sorting options?). Our self-invented four codes are only fit as supplemental not leading a column, and the specimen description is verbose and again complicated (as in: compound not simple). YBG, could you expand? -DePiep (talk) 14:47, 19 August 2021 (UTC)

Bit beter now, YBG, but why leave my setup at all? -DePiep (talk) 05:29, 20 August 2021 (UTC)

This is a simple solution. Why complicate matters? -DePiep (talk) 11:53, 20 August 2021 (UTC)

OK, what do you think of this? I was unnecessarily trying to squeeze the anion column just a bit narrower, but it is not really worth it. YBG (talk) 00:42, 21 August 2021 (UTC)

@YBG: This one is respecting the various aims in play, very acceptable. Let's keep this one. IMO: your aim to squeeze this table marginally narrower is a bit overzealous; unless a grand redesign is made, narrowing is futile. -DePiep (talk) 06:47, 26 August 2021 (UTC)

:::This one is outstanding. Sandbh (talk) 06:13, 26 August 2021 (UTC)

All resolved?

@Sandbh, Petergans, Double sharp, and DePiep: As near as I can figure, everything mentioned throughout this #Major revision (2) section has been resolved, and so this section is ready to be archived. If anyone disagrees with me, please let me know. Otherwise, in a few days, I plan to archive this section. YBG (talk) 23:39, 22 August 2021 (UTC)

@Sandbh, Petergans, Double sharp, and DePiep: If there are outstanding issues, please clarify what they are. I will wait a few more days before archiving this one. YBG (talk) 06:53, 26 August 2021 (UTC)

Complementary, I strongly suggest to use {{Resolved}} or {{done}} (instead of verbose) to close a topic. Well-structured talkflow helps (eg, one issue per header/bullet). -DePiep (talk) 06:56, 26 August 2021 (UTC)

gtg. Sandbh (talk) 07:41, 26 August 2021 (UTC)

Template:Chem—please use this and not sub- and super-scripts

 Resolved All have been transformed to {{chem2}}, which is better than {{chem}} YBG (talk) 17:49, 21 August 2021 (UTC) ​​​ To get to FL status, formulae need to be presented consistently. Template:Chem is super easy. Sandbh (talk) 06:31, 17 August 2021 (UTC)

I think it would be better to standardize on {{chem2}} which I think is even easier than {{chem}}. YBG (talk) 06:38, 17 August 2021 (UTC)

I have converted all <sub>/<sup> and {{chem}} to {{chem2}}. Added bonus: the charge is immediately above the subscript where present, and the {{hr}} all line up. YBG (talk) 07:25, 17 August 2021 (UTC)

@YBG: Could I trouble you to spruce up the old table, following my revert? Thank you. Sandbh (talk) 07:57, 17 August 2021 (UTC)

@Sandbh: Sure, but not right now. 09:04, 17 August 2021 (UTC)

@Double sharp, Petergans, and Sandbh: I think this section is ready to be archived. YBG (talk) 23:41, 22 August 2021 (UTC)

@Sandbh, Petergans, Double sharp, and DePiep: If there are outstanding issues, please clarify what they are. I will wait a few more days before archiving this one. YBG (talk) 06:55, 26 August 2021 (UTC)

This one is gtg. Sandbh (talk) 07:38, 26 August 2021 (UTC)

Anchors by symbol

I have added an {{anchor}} with each symbol. So one can link to

• #N (in-page), List of aqueous ions by element#N, {{slink}} → List of aqueous ions by element § N, NO−3, 'See nitrogen' (piped wikilinks).

Question/issue:

Some elements have multiple lines (OSs), and their name is positioned vertical-mid. To have the anchor-jump to top of the element row, I'vce added three experiments. Please check / compare effects:

1. List of aqueous ions by element § N jumps to top?
2. List of aqueous ions by element § P jumpos to top?
3. List of aqueous ions by element § S no change: jumps to vertical-mid = bad
4. List of aqueous ions by element § C (single line, to compare)
5. Do these tablerows look OK, or did I misform them?

If 1 or 2 is OK, we'll apply those. -DePiep (talk) 11:48, 19 August 2021 (UTC)

None of these work. In every case, all or part of the element row is hidden by the floating table header. 21:41, 19 August 2021 (UTC)

That's in Mobile view, YBG? -DePiep (talk) 05:30, 20 August 2021 (UTC)

Using firefox on my laptop I see, just below the floating Z/name header respectively: #1 Z=8 O; #2 OS=-2 of Z=16 S; #3 OS=1 of Z=17 Cl; #4 a sliver of the line above OS=5 of Z=7 N. Have you considered using {{ts}} and adding {{ts|vtt}} or {{ts|vt}} to each row? YBG (talk) 00:28, 21 August 2021 (UTC)

This occurs because my preferences have selected the "Make sure that headers of tables remain in view as long as the table is in view" option under "Gadgets > Testing and development". When I deselect that option, the links mostly work ok. Incidentally, the correct way to add anchors to table row is |-id="Cl" and the like, which is what is recommended at Help:Table § Section link or map link to a row anchor. YBG (talk) 06:05, 21 August 2021 (UTC)

Apparently per WP:Village pump (technical)/Archive 183 § Table header blocks line, browsers claim mess up anchors when you have selected "stick headers". Here are the options as I see them:

1. Abandon the attempt at anchors
2. Leave the anchors in and just figure that it won't work with sticky headers. (I'd recommend changing to the |- id="Cl" form).
3. Put the anchor in the row above (again using |- id="Cl"), i.e., link #N to the Carbon row, #O to the Nitrogen row and the like. This will look really confusing in the wiki markup, but I think it would be OK for the reader; I think it would actually be a "feature" to give the reader some context before the anchor.

I personally lean to #3, but would not be opposed to #1. The anchors are a neat feature, but will they really be used? If not, better to drop them entirely. YBG (talk) 06:27, 21 August 2021 (UTC)

Ouch, didn't know they are this unreliable. Thanks for the research (& the gadget tip). For now, we better not rely on anchors indeed.

Do you know of this dysfunctioning with (regular use) #sectiontitles too?

In this table they are maybe skippable (no internal #-links then; maybe some footnote-construct will do). However, in other element lists they are very useful: List of chemical elements#Cl. PS You mean to say they should be entered literally, not {{anchor}}?

{{anchor|Cl}} → <span class="anchor" id="Cl"></span>

I'd go for option #3, with some more testing. -DePiep (talk) 08:57, 21 August 2021 (UTC)

• Option #3 implemented in List of chemical elements (test List of chemical elements § As (multiline), List of chemical elements § Cl. -DePiep (talk) 09:06, 21 August 2021 (UTC)

  I have modified it to |-id=XXX form recommended by Help:Table § Section link or map link to a row anchor YBG (talk) 17:29, 21 August 2021 (UTC)

  @DePiep: This does not affect section titles as there is no floating header to get in the way. The link scrolls to the same place whether the gadget is enabled or not; it is just that when the gadget is enabled, the floating table header gets in the way of the line with the anchor. So you see it has no effect on a section header because there is no floating table header to get in the way. YBG (talk) 22:27, 21 August 2021 (UTC)

diffs please. -DePiep (talk) 22:51, 21 August 2021 (UTC)

Oh I'm fine with current situation +. (and I am bored with original athour absense/behaviour). -DePiep (talk) 22:57, 21 August 2021 (UTC)

@DePiep: I think this section has been resolved and is ready to be archived. Let me know if you think otherwise. YBG (talk) 23:45, 22 August 2021 (UTC)

Still, does the gadget you mention imply: "this anchoring is not functioning as expected in certain situation" caveat apply? And where to put this? -DePiep (talk) 11:48, 25 August 2021 (UTC)

Not 100% sure what you are asking. YBG (talk) 06:59, 26 August 2021 (UTC)

Conclusion

1. There is a Preferences option "Make sure that headers of tables remain in view as long as the table is in view" under "Gadgets > Testing and development".
2. This option keeps table headers in view when scrolling a longer table (while usually, headers roll out of view).
3. However, this scrolling hides table rows, also when jumping to anchor in the table like |- id="Hg":

   [[List of aqueous ions by element|Hg]] → Hg (or List of aqueous ions by element § Hg).

4. This line-hiding is undesired, and possibly a bug (that won't be fixed), see WP:Village pump (technical)/Archive 183 § Table header blocks line (2020).
5. Since the gadget is clearly under Testing and development (T&D), this is a warning to readers who apply it, and so the this behaviour must be deemed accepted. So, we do not have to design pagers (articles) to evade this situation. In-article and between-article tablerow linking is acceptable. We can keep using current setup. -DePiep (talk) 07:17, 26 August 2021 (UTC)

Thanks, that makes it clear that this is ready to be archived. YBG (talk) 07:48, 26 August 2021 (UTC)

Article name change

The article is now called "List of ions in pure water (aqueous chemistry)". Sandbh (talk) 08:15, 26 July 2021 (UTC)

Presumably ref. 3 contains more up-to-date information than Baes & Mesmer.

Hopefully; that said, Baes & Mesmer would still have their place. The age of a book does not necessarily discount its relevance.

The "List" is full of errors, absences and inconsistencies, e.g. Be(HOH)₄²⁺, NH₄⁺, chlorate, chlorite, hypochlorite, Si(O)₃^2-, missing meaning of legend for column 4, to mention just a few. Petergans (talk) 14:54, 26 July 2021 (UTC)

​Citations have been provided for Be(HOH)₄²⁺; and NH₄⁺.

Si(O)₃^2- should've read SiO₃^2-, and has been corrected, thanks.

For Cl₂ in pure water, the only species present are chloride, and [per- Sandbh (talk) 07:04, 29 July 2021 (UTC)] chlorate, according to the cited sources. Other Cl species are not relevant since the scope of the list is limited to pure water, as per the amended article title.

Richens does not mention chlorate, chlorite, or hypochlorite. Sandbh (talk) 07:04, 29 July 2021 (UTC)

A legend has been added for column 4, thank you.

Please be specific with expressions such as "full of errors, absences and inconsistencies". WP articles are improved iteratively rather than being criticized for unspecified errors.

The table has now been fully populated and is fully sortable. Sandbh (talk) 06:46, 27 July 20

It is still a clear inconsistency that H⁺ and Be²⁺ are written with the coordinated waters explicit, whereas no other aqua cations are. Double sharp (talk) 09:37, 27 July 2021 (UTC)

They are written that way in accordance with the sources. These will be (re) checked tomorrow. Sandbh (talk) 14:18, 27 July 2021 (UTC)

Sure, and different sources use different conventions. A source that talks about [Fe(H₂O)₆]³⁺ will surely similarly talk about [Be(H₂O)₄]²⁺. And a source that talks about Fe³⁺ (aq) will surely similarly just talk about Be²⁺ (aq). What matters is consistency. As it stands it looks kind of like an article written in American English that twice refers to "football". Double sharp (talk) 14:40, 27 July 2021 (UTC)

Waters of hydration have been removed. Sandbh (talk) 06:57, 29 July 2021 (UTCQ

Thank you for these changes. There are still numerous errors and inconsistencies, some of which are:

• The limitation to "pure water" rules out all systems such as Cr0₄^2- where acid or alkali must be present for the species to exist

Thanks. This item is not relevant to the defined scope of the article. Cr0₄^2- appears on the predominance diagram at pH ca. 7+ and ca. > 0.5 V. No other species are present other than HOH and OH^-. Sandbh (talk) 14:13, 27 July 2021 (UTC)

• There are issues with all polyoxometalate ions.

If there are "issues" with stable polyoxometalate ions in pure water please provide sources. The article sources will be checked tomorrow to see if any such ions were missed. Sandbh (talk) 14:13, 27 July 2021 (UTC)

• SiO₃^2- is not an anion it is polymeric.

This oxyanion is supported by the citations. Sandbh (talk) 14:13, 27 July 2021 (UTC)

Of course they do, it's a common simplification. That does not mean that the simplification is that close to reality. See Richens p. 151. Double sharp (talk) 14:38, 27 July 2021 (UTC)

Richens (p. 151) says:

"There are no aqua ions of silicon because of the extremely small effective radius of Si4+."

S&P say:

"The species SiO3− is a gross simplification of a very complex situation. In actuality the species represents a large collection of polysilicates plus forms of colloidal hydrated SiO2. The main species present in dilute solution is probably SiO2(OH)2−2, but the line between SiO2 and SiO3−2 is crossed only slowly by simple treatment of SiO2 with aqueous strong base. (p. 183)

Inclination is to retain SiO3− but with a qualifying note. (p. 183) Sandbh (talk) 05:47, 29 July 2021 (UTC)

• MnO^4-

This oxyanion is supported by the citations. Sandbh (talk) 14:13, 27 July 2021 (UTC)

You probably mean permanganate MnO₄⁻. Double sharp (talk) 14:44, 27 July 2021 (UTC)

Thanks. Fixed. Sandbh (talk) 06:53, 29 July 2021 (UTC)

• H(CO)₃

This oxyanion is supported by the citations. Sandbh (talk) 14:13, 27 July 2021 (UTC)

Presumably you mean bicarbonate HCO₃⁻? (Note the absence of parentheses.) Double sharp (talk) 14:41, 27 July 2021 (UTC)

Thanks. Fixed. Sandbh (talk) 06:45, 29 July 2021 (UTC)

• SbOH₃⁺, TeOH₃⁺

The first species is not listed in the table nor is it listed in the sources. The second species is included in the sources provided. Sandbh (talk) 14:13, 27 July 2021 (UTC)

I have tagged the page accordingly Petergans (talk) 09:18, 27 July 2021 (UTC)

In light of the above, that edit has been reverted. Sandbh (talk) 14:13, 27 July 2021 (UTC)

The Te species now shows as Te(OH)₃⁺. Sandbh (talk) 06:45, 29 July 2021 (UTC)

The response above to chlorine appears to coincide with an easily made error. It is true that if you plot Cl species in water on a Pourbaix diagram, only chloride and chlorate appear. That, however, does not mean that the other species cannot occur in water. As explained by G&E 2nd edition pp. 853ff.: hypochlorite disproportionates only slowly at room temperature. The fact that it disproportionates means it is never the most stable species, ergo it does not appear on the Pourbaix diagram. But it is an ion that can occur in water. Same thing goes on with the other chlorine oxoanions. Double sharp (talk) 09:36, 27 July 2021 (UTC)

Thanks. The scope of the article is limited to stable species, as highlighted in the image, and now in the lede. In this context there is no error. Sandbh (talk) 14:13, 27 July 2021 (UTC)

If you have a definition of "stable" that fails to include a species that will persist in water at standard conditions for a long time (citation: household bleach), then it's not a terribly good definition, is it? Double sharp (talk) 14:32, 27 July 2021 (UTC)

P.S. And how stable is Ti²⁺, which you include? Not very according to Richens p. 208, at least. And only in ice-cold hydrochloric acid solution, which as he notes means that complexation by present Cl⁻ (which you want to exclude) is a significant stabilising factor. It seems downright bizarre to impose a standard that includes this but not ClO⁻
for chlorine. And also downright bizarre to include Ti²⁺, yet steadfastly refuse to include Pt²⁺ just because Cl⁻ is present. Never mind that the reason it is present (Richens p. 501) is that the aqua cation is formed from acid-catalysed aquation of original PtCl²⁻
₄, and for obvious reasons that chloride is not going to go back in again once you've done that... Double sharp (talk) 09:49, 28 July 2021 (UTC)

Ti2+ is included in S&P without the presence of chloride, and by Wulfsberg, without comment in each case. I’ll look up Richens tomorrow. Sandbh (talk) 12:00, 28 July 2021 (UTC)

Elsewhere S&P say II and III ions are unstable with regard to HOH except for III in strongly acidic solution. II has been removed. Sandbh (talk) 06:45, 29 July 2021 (UTC)

• Radon: The footnote is in error. RnF₂ decomposes in water with release of elemental radon (Stein), as one would expect from examining the behaviour of the krypton and xenon analogues. No Rn²⁺ aqua cation is known. At least one of the sources you give (doi:10.1039/C39850001631) makes it clear that cationic radon occurs in non-aqueous solutions. Which this article is supposedly not about. Double sharp (talk) 09:42, 27 July 2021 (UTC)

Thanks. Since RnF₂ occurs in non-aqueous solutions that is why mention of it occurs in a note, as an item of passing interest, rather that in the main table (nor is it reflected in the PT image). Sandbh (talk) 14:13, 27 July 2021 (UTC)

The note still reads "Radon...has been reported to exhibit cationic behaviour when RnF₂ is dissolved in water". This is, as I pointed out, simply false. Double sharp (talk) 14:33, 27 July 2021 (UTC)

Thanks. The note has been removed since cationic Rn is reported to occur in non-aqueous solutions. Sandbh (talk) 05:33, 28 July 2021 (UTC)

Further name change
The article is now called "List of stable ions in pure water (aqueous chemistry)". Sandbh (talk) 23:19, 27 July 2021 (UTC)

Title: "Ions in pure water" is too broad. I suggest "List of aqua-ions and their hydroxo- and oxo- derivatives in aqueous solution". N.b. the pH range is irrelevant when the title refers to aqueous solutions. Petergans (talk) 12:26, 28 July 2021 (UTC)

Great suggestion @Petergans:, solves a number of issues. Thanks. Done. Sandbh (talk) 08:02, 29 July 2021 (UTC)

Polymetallates and such
​​The image and table have been updated. No additional polyoxometalate ions, aaide from the table entries for isopolyanions were encountered during the process of checking the listed sources. Outlying entries for species at pH < O and pH > 14 were added via table notes. As noted, the Sandbh (talk) 03:06, 28 July 2021 (UTC)

Outstanding comments by Double sharp will be addressed shortly.

Thanks for many comments from all. Sandbh (talk) 03:06, 28 July 2021 (UTC)

? @Petergans, Sandbh, and Double sharp: I can't tell whether the issues raised in this section have been dealt with or not. Is this section ready to be archived? YBG (talk) 22:25, 22 August 2021 (UTC)

Yes. Sandbh (talk) 07:47, 26 August 2021 (UTC)

Technetium cations?

There is some problem here, although maybe unsurprisingly given that this element is radioactive. This Japanese atlas accepts some cations TcO²⁺, TcOOH⁺. Richens (p. 349) does not dispute that there might be some cationic species in low oxidation states, but doubts that these are the real formulae, writing "The species 'Tc³⁺' and 'TcO²⁺' are almost certainly oligonuclear. 'TcO²⁺' could be the di-μ-oxo dimeric species, Tc₂O₂(μ-O)₂⁴⁺..." (Shades of "ZrO²⁺" indeed.) So, maybe there is some sort of cation, but we have no idea what the real formula is. Double sharp (talk) 04:30, 7 August 2021 (UTC)

B & E report TcO2+, TcOOH+, and TcO(OH)3−. Tc needs to become orange and turquoise. Sandbh (talk) 08:14, 7 August 2021 (UTC)

@Sandbh and Double sharp: I'm not sure if this has been resolved or not. Please let me know; if it is, I'd like to archive the section. YBG (talk) 22:46, 22 August 2021 (UTC)

This one is outstanding. Sandbh (talk) 06:06, 26 August 2021 (UTC)

@Sandbh: Could you clarify what the outstanding issue is to facilitate moving the discussion forward? YBG (talk) 06:48, 26 August 2021 (UTC)

I need to check the colouring on the PT. Holding off loading an update of the PT until things settle down. But I may do it anyway, soonish. Sandbh (talk) 07:43, 26 August 2021 (UTC)

@Sandbh:

1. Is the outstanding issue related to which technetium ions are in the table? If so, then that issue and this section is unresolved.
2. Is the outstanding issue merely related to uploading a new version of the PT? Then this section about technetium can be marked resolved; the table will be updated without or without this section.
3. If the outstanding issue is something else, I'm not sure what the status of this section should be.

YBG (talk) 15:56, 30 August 2021 (UTC)

@YBG: Please go ahead and archive this one. Sandbh (talk) 00:33, 2 September 2021 (UTC)

Platinum

The aqua ion should be included. Perchlorate is essentially a non-coordinating ion in this context. Indeed, I'd actually consider it a mistake to exclude aqua ions that form in its presence. Double sharp (talk) 02:22, 21 July 2021 (UTC)

I've included it as a note, but not in the main table since Pt ions require the presence of at least Cl⁻ in aqueous solution, whereas the table notes it is for stable species in aqueous solution where no agents producing complexes or insoluble compounds are present other than HOH and OH−. Sandbh (talk) 13:36, 21 July 2021 (UTC)

The Pt²⁺ aqua ion reacts with chloride: doi:10.1021/ic00190a017. Which at least strongly suggests that presence of chloride is not necessary to form the ion, and that it's just that using K₂PtCl₄ is an easy way to get platinum in aqueous solution. Double sharp (talk) 15:46, 21 July 2021 (UTC)

”Platinum forms no aquo-ions, so strong is its tendency to form hydroxy-species. Alternatively, if suitable ligand anions, such as chloride, are available in an aqueous reaction mixture, it complexes with them.” Cotton & Hart 1975, The Heavy Transition Elements, p. 108. Sandbh (talk) 04:16, 25 July 2021 (UTC)

Hydroxy species are just the partially hydrolysed forms of an aqua ion. So even if you disbelieve in the aqua ions (and it's true that sources tend to contradict each other on very acidic cations), this implies that Pt should be listed as forming oxycations, just like Sb. (In any case, the distinction between the aqua cation and, say, the aqua cation with one proton less does not seem all that important when it comes to describing what is going on when it reacts with other species.) Double sharp (talk) 10:26, 26 July 2021 (UTC)

The presence of a stable Pt²⁺ aqua ion in pure water is easily able to be added to the two tables if a source is supplied. No such species in pure water is mentioned by either G&E, Wiberg, or C&W. Sandbh (talk) 04:51, 28 July 2021 (UTC)

Pourbaix diagram for Pt. Review of known metal-aqua cations as of 2010 (includes platinum). Double sharp (talk) 09:22, 28 July 2021 (UTC)

The first article has question marks next to the Pt²⁺ aqua ion. The second article refers to this article which relies on the presence of perchlorate. Sandbh (talk) 11:47, 28 July 2021 (UTC)

By those standards, Mo³⁺ is equally inadmissible (Richens pp. 285–6; this one requires triflate, because perchlorate oxidises it), and yet it is still there. So either Pt²⁺ should be put in, or Mo³⁺ and some other 4d and 5d cations should be removed.

The standards you are imposing are specific to what you write on the Pourbaix diagram, and do not necessarily cover every major species you get from the element in aqueous solutions. Serious reviews on the aqua chemistry of such metals (e.g. Richens, Parish, Persson) don't seem to mind too much the need to have some involvement of non-coordinating anions. Pourbaix diagrams are reflecting something, that's all very well, but they are not the last word on what species are essentially stable (because of kinetic factors), or on what other anions can be added without causing problems from the formation of other complexes. It's fine to mention the stringent requirements for showing up on the Pourbaix diagram, but on the grounds of the importance of such species, can such household-important species as ClO⁻ and such standard-in-the-literature invocations like Pt²⁺ and Mo³⁺ not at least be included with a note? Double sharp (talk) 12:33, 28 July 2021 (UTC)

In any case, what seems most clear about the 4d and 5d metals is that many have a remarkably low affinity to water as a ligand for forming cationic complexes. Besides Y/Lu and Zr/Hf at the front end, and Ag and Cd at the back end, main-group stereotypes of metallic behaviour seem not very applicable here! Double sharp (talk) 13:11, 28 July 2021 (UTC)

? @Sandbh, Double sharp, Petergans, and DePiep: Have the issues in this section been resolved? YBG (talk) 15:39, 30 August 2021 (UTC)

@YBG: Not really but it'll be OK archiving it. Sandbh (talk) 00:29, 2 September 2021 (UTC)

Alternate ways to display oxidation numbers

This table displays three different ways of displaying oxidation numbers.

Alternatives for displaying oxidation state

Element		Option (a): OS in a separate column				Option (b): OS on each line in each column			Option (c): OS in each formula
antimony		3 5	Sb(OH)+2	Sb(OH)−4 Sb(OH)−6, antimonates		OS=3: Sb(OH)+2	OS=3: Sb(OH)−4 OS=5: Sb(OH)−6, antimonates		Sb(III)(OH)+2	Sb(III)(OH)−4 Sb(V)(OH)−6, antimonates
iridium		3 >3	Ir(OH)2+, Ir(OH)+2	polymeric species		OS=3: Ir(OH)2+, Ir(OH)+2	OS>3: polymeric species		Ir(III)(OH)2+, Ir(III)(OH)+2	polymeric species

Option (c) doesn't seem very practical as it isn't clear how to indicate the oxidation state on names of ions as opposed to forumlas, consequently it seems we have an option of the status quo (a) or the alternative (b). Thoughts? YBG (talk) 08:10, 7 September 2021 (UTC)

Leave things as they are. There are serious issues concerning content that need to be resolved before considering changes to layout. Petergans (talk) 11:20, 7 September 2021 (UTC)

Option (a) only. The other two are needlessly repeating info; also they require an incurrent chemical formula notation. + soft support for Petergans' notion. -DePiep (talk) 11:26, 7 September 2021 (UTC)

 Resolved I introduced this section because Petergans voiced the opinion that column 2 (OS) was redundant. As he prefers to leave things as they are, there seems no need to continue this thread. YBG (talk) 15:40, 7 September 2021 (UTC)

Metal ions in aqueous solution

These comments follow on from the talk page of Metal ions in aqueous solution.

1. A serious defect in the table is the absence of data for solutions of salts with "non-coordinating" anions such as perchlorate, triflate, etc.

   As the article makes clear, its scope is limited to aquo-ions in pure water. Not in e.g. chloride or perchlorate solutions. What therefore is the issue? Sandbh (talk) 02:53, 26 July 2021 (UTC)

   The issue is that that makes it rather a strange idea, unless I miss something. I don't see how you're going to get Ag⁺ in pure water. The hydroxide is insoluble, the metal won't react with water, and presumably you are not using acid (as you want pure water); so you must have gotten it in from another of its salts. But in that case, the water is not pure, because it has the anion in it as well. And even if you can do it, is that really what we're most concerned about? Is keeping the water scrupulously free of counter-anions something that is often important to do, when "non-coordinating" anions will do just as well? Double sharp (talk) 10:29, 26 July 2021 (UTC)

   Interim response. The article illustrates one aspect of the comparitive chemistry of the elements. This requires a level playing field. Hence chloride ions, for example, are not permitted. Sandbh (talk) 04:57, 28 July 2021 (UTC)

   Response cont'd. Schweitzer & Pesterfield explain how E-pH predominance diagrams are drawn up chapters 1 to 4 (net 95 pp.). The first step is to start "with the species of element involved which contain one or more of the following entities: the element, O and H. This is best done by reading the descriptive chemistry of the element in a good inorganic text and identifying the species, both soluble and insoluble, which persist, at least for several minutes, in aqueous solution." (p. 27) From there, one uses the standard free energy of every species in the equations involved. The Nernst equation is then solved as a function of pH and the concentrations of the soluble species. In the case of Ag, the oxide is soluble. Sandbh (talk) 06:28, 28 July 2021 (UTC)

   Ag₂O is soluble because of formation of hydrolysis products. So you still don't have Ag⁺ in pure water, you'll have species like [Ag(OH)₂]⁻ present. See Cotton and Wilkinson 2nd ed. p. 1042. But if that's a problem for you, then try rhodium. Both Rh(III) and Rh(IV) oxides are quite insoluble.

   Species like [Ag(OH)₂]⁻ are not a problem, since there is nothing else there aside from Ag, O, and H, as per the S&P requirement. They say [Ag(OH)₂]⁻ is sometimes written AgO ⁻. On their Pourbaix diagram they show it at just shy of pH 15, in a tiny patch. I’ll add this shortly and update the image. Thanks for spotting this. Sandbh (talk) 12:18, 28 July 2021 (UTC)

   And what about rhodium then? Double sharp (talk) 12:43, 28 July 2021 (UTC)

   It doesn't make any sense to consider non-coordinating anions as a problem. By definition, they are not going to complex with the metal ion, ergo the situation is going to be the same as if it wasn't present. It just makes it easier to get the metal aqua ion into solution in the first place. It's still a level playing field to include them for everybody. Double sharp (talk) 09:20, 28 July 2021 (UTC)

   Pending Sandbh (talk) 07:14, 29 July 2021 (UTC)

2. The gaps at tantalum and osmium are a matter of concern. The issue here is that it is impossible to prove the non-existence of a species.

   The legend for "white" has been changed to "unknown". Will this do? Sandbh (talk) 02:53, 26 July 2021 (UTC)

3. It is unlikely that tungsten does not form a relevant species if molybdenum do so.

   Given the numerous anomalies seen all over the periodic table, this should come as no surprise. Chemistry operates according to the way the universe is "designed" rather than necessarily the way humans expect it to work.

   Mo forms the green-yellow Mo⁺³ cation at pH > 1. W does not, being limited to colourless polyanions (pH 0 to 9) and WO₄⁻² at pH > 9.

   According to the Pourbaix diagram for W, ph –2 to 16, –1.8 to 2.2 V, only the hexavalent tungsten derivatives (tungstic anhydride WO₃ and the tungstates WO₄⁻ are stable in the presence of water, at 25°C.

   Baes and Mesmer (1976, p. 257) say:

   "The aqueous chemistry of tungsten is simplified by the fact that only tungsten (VI) is stable in water in noncomplexing media…Above a pH of 8 to 9 only the tetrahedral WO₄²⁻ ion occurs. As the pH decreases slow polymerization takes place. The slow kinetics and the confusing nomenclature notwithstanding, the species formed in tungsten (VI) solutions are relatively well characterized." (p. 257)

   Lidin (1996) writes of W: "Forms no cations in solution" (Inorganic Substances Handbook, p. 423)

   Housecroft & Sharpe (2008) write, "W³⁺(aq) is not known" (Inorganic Chemistry, p. 759)

   If there any sources for a W aquo-cation please provide. Sandbh (talk) 02:53, 26 July 2021 (UTC)

   Update: Baes and Mesmer have nothing to say about a W aquo-cation. Their limited predominance diagram for W shows only oxyanions. Sandbh (talk) 07:02, 26 July 2021 (UTC)

   In this case Sandbh is correct (Richens p. 294). The different behaviour of Mo and W here is due to a relativistic effect (expansion of 5d orbitals). This favours W≡W triple bonding, so cationic W aqua species are polynuclear (Richens p. 307). Double sharp (talk) 12:42, 28 July 2021 (UTC)

4. For Pt(II) see Baes and Mesmer, "The Hydrolysis of Cations", pp 264-265.

   Thanks. Will look up. Noting Baes and Mesner are from 1976, it would be a pleasant surprise to learn of a Pt aquo-cation, given such an entity is not found among the other sources listed in the article.

   Update: There was no surprise. Baes and Mesmer write:

   "Palladium and platinum. Both elements have +2 oxidation states, and platinum has a stable +4 state in water…There is essentially no information on Pt(IV) except for the evidence from solubility studies that Pt(IV) is extensively hydrolyzed in acidic solutions. Both elements form a great array of complexes with most ligands, and they tend to complex strongly with the so-called soft ligands…That platinum(IV) is extensively hydrolyzed is indicated…in perchloric acid solutions."

   Whereas they provide a predominance diagram for Pd there is no such diagram for Pt. Their only reference to Pt(II) is to chloride complexes. Sandbh (talk) 07:02, 26 July 2021 (UTC)

   Lidin (1996) writes of Pt: "Has no aquacations" (p. 343)

   Rich (2007), in discussing Pd and Pt, mentions Pd²⁺ but says nothing about a Pt equivalent (Inorganic Reactions in Water, pp. 248–249) Sandbh (talk) 02:53, 26 July 2021 (UTC)

5. For details concerning actinide aqua-ions, including the values of their first hydrolysis constants, see Baes and Mesmer, pp 169-192.

   The existing sources cover the An aquo-ions. Will look up anyway. Sandbh (talk) 02:53, 26 July 2021 (UTC)

   Update: Baes and Mesmer run out of puff after Pu. This 1976 reference is showing its age. Sandbh (talk) 07:02, 26 July 2021 (UTC)

Petergans (talk) 11:33, 25 July 2021 (UTC)

Thanks Petergans for prompt thoughts . Sandbh (talk) 02:53, 26 July 2021 (UTC)

@Petergans: Is this section ready to be archived? YBG (talk) 22:22, 22 August 2021 (UTC)

? @Sandbh, Petergans, Double sharp, and DePiep: I failed to ping everyone. If there are outstanding issues, please clarify what they are, otherwise, let me know if this can be archived. YBG (talk) 07:55, 26 August 2021 (UTC)

I believe so. Sandbh (talk) 08:02, 26 August 2021 (UTC)

 Resolved It appears everything in this section has been resolved and it is ready to archive. YBG (talk) 16:12, 30 August 2021 (UTC)

Oxidation state values

 Resolved YBG (talk) 03:10, 2 September 2021 (UTC)

Wouldn't it be helpful if the table shows all OSs, not just the multi ones? -DePiep (talk) 20:47, 23 August 2021 (UTC)

Feel free to add them. YBG (talk) 02:24, 24 August 2021 (UTC)

I added them, based on what was there. Now wondering what happened to TcO−4 and ReO−4, though. (Richens p. 357 says they are stable.) I'll probably need to go through Richens to check through this again. Double sharp (talk) 04:00, 24 August 2021 (UTC)

data-sort-value added

To obtain meaningful sorting by OS, I have added this |data-sort-value:

val = (OS1+10)*10000 + (OS2+10)*1000 + (OS3+10)*100 + (OS4+10)*10 + (OS5+10)*1

Thus first sorting is by OS1 (ascending); within same OS1 sort by OS2 etc. -DePiep (talk) 13:23, 25 August 2021 (UTC)

I have changed the numeric sort key to an alpha key that will be much easier to maintain:

/OS1/OS2/OS3/OS4/OS5/

YBG (talk) 06:18, 26 August 2021 (UTC)

But this sorts 1st order: -1, -2, -3, 1, 2, 3. -DePiep (talk) 06:24, 26 August 2021 (UTC)

Good point. Let me think on this for a while. YBG (talk) 07:04, 26 August 2021 (UTC)

I think it is fixed. -1→0z-1, -2→0y-2, -3→0x-3. Not ideal, but at least semi-mnemonic. and as there are very few negative ions, it won't make much difference. YBG (talk) 07:51, 26 August 2021 (UTC)

Negative oxidation states

The oxidation states given for HS^-,Cl^-, H₂As^-, HSe^-, Br^-, I^-, Po^2- are all incorrect. I have corrected only the entry for tellurium(-1). Petergans (talk) 15:29, 18 August 2021 (UTC)

To check for later edits re this: compare. -DePiep (talk) 12:00, 20 August 2021 (UTC)

working: HS^-, Cl^-, H₂As^-, HSe^-, Br^-, I^-, Po^2-

I have added a "^[?]" for each. Could be either a wrong entry or the right o.s. (subrow) should be added. -DePiep (talk) 12:13, 20 August 2021 (UTC)

The oxidation states of the elements in the ions are as follows.

Cl^-, Br^-, I^-: -1

HS^-, HSe^-, Po^2-: -2

H₂As^-: -3

Petergans (talk) 21:02, 20 August 2021 (UTC)

@Petergans: I think they're all fixed. Could you double-check? Thanks!! YBG (talk) 01:11, 21 August 2021 (UTC)

All OK except for polonium (which I forgot to mention);I tried but can't get the layout right for Po. Petergans (talk) 11:33, 21 August 2021 (UTC)

The spacing problem is that if there is nothing between two {{hr}} or before the first or after the last one, the line is narrowed. The fix is to ake sure there is to add   and then the spacing works out OK. I'm not sure what ​ is or whether it works; I've changed all occurrences to nbsp. YBG (talk) 16:57, 21 August 2021 (UTC)

Astatine: G&E say that oxidation states for At -1, 0, +1, +5 and +7 have been identified, but gives no other information, so the chemical formulae given are conjectural. I will remove them.Petergans (talk) 11:33, 21 August 2021 (UTC)

Thank you. I think this table should only include ions that have been experimentally confirmed, and I think I added text to that effect in the lede section. YBG (talk) 16:57, 21 August 2021 (UTC)

But significant work has been done on At since, e.g. [4] [5] [6]. Experiment combined with calculation to interpret the data. Double sharp (talk) 03:00, 23 August 2021 (UTC)

@Petergans and DePiep: I think everything mentioned in this section has been resolved. If this is not the case, please let me know. Otherwise, I will archive this section in a few days. YBG (talk) 23:43, 22 August 2021 (UTC)

@Sandbh, Petergans, Double sharp, and DePiep: If there are outstanding issues, please clarify what they are. I will wait a few more days before archiving this one. YBG (talk) 06:55, 26 August 2021 (UTC)

This is outstanding, given the discussion about Po, and the related question of At (aq). Sandbh (talk) 07:37, 26 August 2021 (UTC)

The issue of incorrect oxidation numbers, which is what started this thread, has been resolved. The discussion of Po and At continue at § Polonium and § Astatine (aq). @Sandbh:, could you make sure that any relevant comments from this section are added to those sections so that everything in the Po and At discussions can be in one place? Once we're sure that has been done, I think we can mark this section as resolved. YBG (talk) 21:07, 26 August 2021 (UTC)

@Sandbh: Could you please check to see if there is anything in this section regarding Po or At that is missing in the specific discussions in those sections? YBG (talk) 03:19, 2 September 2021 (UTC)

 Resolved This section is ready to be archived. YBG (talk) 22:11, 15 September 2021 (UTC)

Archiving

I've tried to go though this talk page and identify which issues have been resolved and which still need to be discussed. I have suggested archiving the sections that have been resolved, but didn't want to do that WP:BOLDly. I tried to ping everyone who contributed to each section, but I may not have been fully complete. If you search for "archive" I think you will find all of my suggestions. Feel free to push back if you think I am rushing things. YBG (talk) 23:49, 22 August 2021 (UTC)

The following issues are still outstanding. I have waited until the current spate of edits has calmed down, before raising them.

1. Notes section. Most of the notes are redundant. Anything significant should be placed in the introduction. References belong in the references section, not in the table section. Citations of both May and Takeno are already there and don't need to be duplicated in the notes. The note concerning oxyanions of chlorine is wrong - confusion between thermodynamic stability, chemical reactivity and kinetic lability is not unusual in WP.
2. Summary of species. This column duplicates what is contained in other columns of the table. It is redundant, as are the species types in row 2.
3. Noble gases. Only Xenon forms oxyanions which are stable enough in water to have been characterized.

Petergans (talk) 07:18, 23 August 2021 (UTC)

The sort of thing I would want to use notes for are cases like astatine and radon, where for obvious reasons there aren't clear-cut characterisations as for the stable elements, yet we have some referenceable suggestions of what might be forming. In other words, something not secure enough for a full table entry, but enough to give more than just a bald blank. Double sharp (talk) 09:17, 23 August 2021 (UTC)

Issues like this deserve to be discussed in the body of the article. The occurrence of vey low concentrations is not restricted to these elements. It applies also to hydroxides like Ca(OH)₂ (lime water) which are sparingly soluble in water. In such cases speciation must, of necessity, be conjectural. I don't understand why the contents in note C were relegated to a note; this system exemplifies the difficulties encountered in establishing which species are present in solution. Petergans (talk) 14:27, 23 August 2021 (UTC)

re note C: This appears in the middle of the paragraph describing the list's rather complex scope. The 3 paragraphs (8 sentences!) of the footnote give examples for one type of exclusion; if they were included in the main body, it would make it much more difficult to see the big picture of inclusions/exclusions. YBG (talk) 03:18, 24 August 2021 (UTC)

re Summary of species: This has already been discussed. The only objection to this column came from Petergans; YBG and DePiep explicitly stated their approval of it to allow readers to explore via sorting. I believe Sandbh also approves, but I cannot locate an explicit comment to this effect. YBG (talk) 03:18, 24 August 2021 (UTC)

Support. Sandbh (talk) 06:16, 26 August 2021 (UTC)

re Radon: If this is the same situation as astatine, the species should be removed to a footnote. Double sharp, could you do this? YBG (talk) 03:18, 24 August 2021 (UTC)

@YBG:  Done Double sharp (talk) 03:52, 24 August 2021 (UTC)

(Perhaps by this standard suspected At species should be mentioned in the footnotes. Though it often seems terribly unclear still, so perhaps only the ones suspected by almost everybody e.g. At⁻ and AtO−4.) Double sharp (talk) 15:43, 25 August 2021 (UTC)

• About the image (PT): remarks are scattered here; I don't think, in general, these should be archived. -DePiep (talk) 20:50, 23 August 2021 (UTC)

It has been over three days since I marked things "ready to archive", so I'm going to start the process, trying to take a conservative approach of not archiving unless it is really clear to me and there has been no opposition. If you find any mistakes and decide to archive instead of starting a new discussion, make sure that you revert both the change to this page and the change to the archive. YBG (talk) 06:28, 26 August 2021 (UTC)

I've finished archive for today. Thanks for your help. Hopefully, now that completed tasks have been archived, it will be easier to pay attention to what is outstanding. YBG (talk) 08:00, 26 August 2021 (UTC)

 Resolved There are no issues remaining in this section; it will be archived soon. YBG (talk) 06:06, 16 September 2021 (UTC)

Major revision (1)

I have completed a major revision of the article. This includes

removal of three columns that now serve no purpose (other columns renamed)

complete revision based on Baes and Mesmer (personal copy)

Further revision will be undertaken after I have borrowed a copy of Richens from Leeds University library, today. Petergans (talk) 10:31, 3 August 2021 (UTC)

Looking good Petergans. Sandbh (talk) 11:21, 3 August 2021 (UTC)

Image update etc. to follow. Sandbh (talk) 11:33, 3 August 2021 (UTC)

Thanks. It would be good for us to avoid edit clashes, if possible. Any suggestion? BTW I've already found material to add, from Richens. P.S. Richens did his Ph.D. with Geoff Sykes in Newcastle, hence the greater emphasis on kinetics in his book. Geoff was a friend and colleague at Leeds for many years before his appointment to a chair in Newcastle. Petergans (talk) 18:13, 3 August 2021 (UTC)

Edit clashes should not be an issue. That is why I was posting the updates here to help you keep track of things. Even if there is clash I'd expect it would be quickly sorted out. Thanks for news about your contacts. They're nice to discover in the process of developing an article. Happens to me too, from time to time. I'll now turn to updating the image. I expect I'll have some questions for you thereafter. Sandbh (talk) 00:04, 4 August 2021 (UTC)

The updated image is there. Sandbh (talk) 01:54, 4 August 2021 (UTC)

References need revision to remove duplicates such as for Richens' book. Petergans (talk) 09:41, 4 August 2021 (UTC)

To follow. Sandbh (talk) 11:45, 4 August 2021 (UTC)

I see the image will have to be updated once more. Sandbh (talk) 13:06, 4 August 2021 (UTC)

@Petergans, Sandbh, and Double sharp: It looks to me like there are no outstanding issues in this section and it is ready to be archived. I plan to archive it in a few days unless someone tells me it should not be. YBG (talk) 22:41, 22 August 2021 (UTC)

This one is outstanding. Sandbh (talk) 06:04, 26 August 2021 (UTC)

@Sandbh: Could you clarify what the outstanding issue is to facilitate moving the discussion forward? YBG (talk) 06:45, 26 August 2021 (UTC)

Outstanding: References need revision to remove duplicates such as for Richens' book. Sandbh (talk) 07:44, 26 August 2021 (UTC)

@Sandbh: The only duplicated reference now is Russel & Lee (2005), but the two references cite different page numbers. Should we do something about that? Or leave it as is since it has different page numbers? YBG (talk) 00:42, 19 September 2021 (UTC)

@YBG: This one can be closed. Russel & Lee (2005) is not a duplication since different page nos are being invoked. Sandbh (talk) 07:02, 19 September 2021 (UTC)

Color coding the PT

Periodic table color-coded by the species of ions each element can form

The color codes in the PT seem difficult to decode mentally, and unnecessarily obscure commonalities between elements. For example, in the graphic posted on the article page today, the group 3 elements Sc/Y/Lu/Lr have this in common: They all have cationic species. Yet these four elements bear three different colorings, and in requires a great deal looking back and forth between the PT and the key to recognize this commonality.

A simple solution would be to divide each element cell into up to four quadrants. For elements that form only one species of ion, color the entire cell that color. For elements that form two species, color half in one color and half in the other color. For elements forming three or four species of ion, use three or four different colors.

The graphic shown here illustrates how this could be done. But please treat it merely as a draft. I notice now that the cell labeled "Cation" has an odd and unsightly border because that cell in my spreadsheet was selected when I captured the graphic. Also, the data reflects an earlier version of this page, and the nomenclature ("Oxyanion" and "Oxycation") also reflect what was on this page earlier. And please ignore my notoriously bad judgement in color selection.

I have uploaded a new version consistent with the data in the article. YBG (talk) 02:12, 6 August 2021 (UTC)

And again YBG (talk) 22:16, 21 August 2021 (UTC) +1 changing radon & color scheme. YBG (talk) 05:13, 24 August 2021 (UTC)

All of these issues can be rectified if we reach a consensus to use this sort of encoding. I can make the adjustments without too much difficulty; I am also willing to share the spreadsheet if someone else wishes to tackle this work.

This style of color coding allows the reader to clearly see micro-commonalities between elements and sets of elements and also see the trends across large regions of the PT.

Comments, anyone?

YBG (talk) 23:28, 5 August 2021 (UTC)

Support. I've been focusing on getting the data and comments into order, and was then going to address colour coding. Sandbh (talk) 23:42, 5 August 2021 (UTC)

@Sandbh: Do these colors work OK? If not, do you have any alternative suggestions? Pick the RGB or HSL codes and I'll change my spreadsheet to accommodate them. YBG (talk) 00:46, 6 August 2021 (UTC)

@YBG: I like this colour-coding a lot. :) Double sharp (talk) 02:31, 6 August 2021 (UTC)

Comment I feel that the red and pink are too visually similar, and I also discovered that the blue and pink are almost indistinguishable to some colorblind viewers. This was a key point when coloring one of the nuclear charts for island of stability (the KTUY one). I'll give this some more thought tomorrow. ComplexRational (talk) 03:58, 6 August 2021 (UTC)

Here are some colorblind-safe suggestions from ColorBrewer:

1. colorbrewer qualitative paired n=4	Cationic species	Hydroxy- & oxy- cationic species	Anionic species	Hydroxy- & oxy- anionic species
2. colorbrewer diverging PiYG n=4	Cationic species	Hydroxy- & oxy- cationic species	Anionic species	Hydroxy- & oxy- anionic species
3. colorbrewer diverging PiYG n=6	Cationic species	Hydroxy- & oxy- cationic species	Anionic species	Hydroxy- & oxy- anionic species
4. colorbrewer diverging BrBG n=6	Cationic species	Hydroxy- & oxy- cationic species	Anionic species	Hydroxy- & oxy- anionic species

Thoughts? YBG (talk) 04:55, 6 August 2021 (UTC)

I've selected scheme #4. Other suggestions welcome; the change is incredibly simple. YBG (talk) 05:13, 24 August 2021 (UTC)

I will get to this once the technical details of which elements form which ions more or less settles down. Sandbh (talk) 03:56, 7 August 2021 (UTC)

@Sandbh: How long does it take you to create a new version? I just now uploaded a new version of the one shown at #Color coding the PT and it took me 25 minutes from the time I screen-scraped the data from the list to the time I uploaded the file. And about 15 minutes of that was taken up trying to figure out what was wrong with my screen grab tool until I finally gave up and rebooted. So I reckon I could easily produce a new one in about ~10 minutes whenever the table changes. YBG (talk) 07:53, 27 August 2021 (UTC)

If I may interject something, it seems to me like there must be some way to get the table to automatically update in response to the entries in Wikitext. :) Double sharp (talk) 15:36, 27 August 2021 (UTC)

Like these? -DePiep (talk) 15:41, 27 August 2021 (UTC)

@Double sharp and DePiep: Unfortunately, of the two table formats used - the one Sandbh has created that have been displayed in the article and the ones that I have generated that have been displayed in this talk page section -- neither is generated in wikitext. Mine is an excel spreadsheet, and I believe Sandh's is also. Of the two formats, I think mine would be easier to adopt to wikitext format, but I don't know how you would do that. I don't know how you would have a table cell with a background color that is different for different portions of the cell. If someone could point me in that direction, I'd be willing to take a stab at it. YBG (talk) 15:48, 30 August 2021 (UTC)

Could be by googling "css background patterns". Don't have time now to explore. -DePiep (talk) 17:17, 30 August 2021 (UTC)

I think it is fair to state that this thread has reached an end without a consensus to change anything. I will archive it soon. YBG (talk) 22:09, 15 September 2021 (UTC)

Mini-RFCs

@Sandbh, Double sharp, and Petergans: Here are some areas where I disagree with the current presentation. Input from other editors would be helpful. YBG (talk) 06:04, 7 August 2021 (UTC)

ps, if we reach a consensus to make a change, I understand that the change may not occur immediately. YBG (talk) 06:07, 7 August 2021 (UTC)

Mini-RFC 1: Cell borders

Sandbh believes cell borders serve primarily as dividers between cells, and so the borders on the edge of the table are mere chartjunk that should be removed. I believe that the cell borders serve primarily to define the cells and as such are an essential visual element whose absence at the edges of the table is distracting. YBG (talk) 06:04, 7 August 2021 (UTC)

Should all cell borders be displayed?

• Yes as nominator YBG (talk) 06:04, 7 August 2021 (UTC)
• Weakly yes in that I don't really mind either way, but would prefer the borders to be there rather than not. Double sharp (talk) 07:38, 7 August 2021 (UTC)
• No need. I follow the information design philosophy of Edward Tufte as set out in e.g. The Visual Display of Quantitative Information, 2001, the nub of which is to use the least sufficient amount of lines when presenting information in a chart. Having said that, I'll post a fully bordered table here, for comparitive purposes. Sandbh (talk) 08:07, 7 August 2021 (UTC)

  Thank you for you willingness to provide a comparison. Could I trouble you for two more examples: thin and wide white cell borders for every element with a pale non-white color for elements with no ion species. Then we could contrast the present hybrid approach with three alternatives that have all four borders of every cell presented identically, either (a) dark hairlines, (b) thin white lines, or (c) wide white lines. YBG (talk) 19:22, 7 August 2021 (UTC)

To follow in due course. Sandbh (talk) 07:46, 8 August 2021 (UTC)

(1) All cells with borders (Sandbh (talk) 02:00, 17 August 2021 (UTC)):

(2) All cells with thin white borders (Sandbh (talk) 02:23, 17 August 2021 (UTC)):

(3) All cells with thick white borders Sandbh (talk) 02:55, 17 August 2021 (UTC):

Evaluation

Which is better? (0) Existing version with internal black borders (1) Full black borders (2) Thin white borders (3) Thick white borders. YBG (talk) 03:48, 17 August 2021 (UTC)

@DePiep, Double sharp, Petergans, and Sandbh: Surely others have opinions about this besides me. YBG (talk) 20:46, 26 August 2021 (UTC)

• 1>3>2>0 All of these options are better than the current internal-only borders YBG (talk) 03:48, 17 August 2021 (UTC)
• I like 3 because there is no need for black lines around elements, when white space does just as good a job. The dashed lines stand out better too. Sandbh (talk) 07:48, 28 August 2021 (UTC)

  @Sandbh: In the absence of strong opinions by others, I am glad to accept white borders because it is a huge improvement over the current table. I believe this would also be acceptable to Double sharp who voiced weak support for a change above. Unless anyone objects, I will mark this mini-RFC as Resolved. YBG (talk) 16:01, 30 August 2021 (UTC)

 Resolved It seems that white borders are acceptable to all. YBG (talk) 03:15, 2 September 2021 (UTC)

Mini-RFC 2: Dashed line

Sandbh believes the dashed line is helpful to separate the anionic-species-only elements from the elements that include some cationic species. I find it distracting clutter (and would even think so without the zigzags to follow the diagonals). I agree that the pattern - anionic-only vs. the rest - is a useful thing, but I believe that the blue, purple, and greenish colors are sufficient to accentuate the pattern in the current graphic. And if the the suggestions in § Color coding the PT are followed, the pattern is still obvious. YBG (talk) 06:04, 7 August 2021 (UTC)

Should the dashed line be removed?

• Yes as nominator YBG (talk) 06:04, 7 August 2021 (UTC)
• Yes, because the divide is so complicated that it's not clear how to interpret the line (there already need to be little arrows on it), whereas the colour-coding clarifies things. Double sharp (talk) 07:39, 7 August 2021 (UTC)
• No. One of the purposes of the PT in the image is to show a left-to-right transition in metallic character via the use of red-orange-sand-yellow colours for the metals, and turquoise, blue and violet colours for the nonmetals, The dashed line shows there's some validity to the notion of a dividing line between metals and nonmetals, and the notion of metalloids. The footnotes in the image just under where the dashed line finishes explain what the line demarcates.

Bubble "I", as I write, shows that Stein (1987) presaged such a line. The path the line takes along Sb-Po-Te-At shows how much trouble the old chemists had in working out whether these elements were metals or nonmetals, or something else. The dashed lines around the Nb-Ta-W-Re-Tc-Os-Ir heptad serves to remind us that, per bubble F as I write this, many of the transition metals are known for their nonmetallic chemistry[7], and that this is particularly seen in the image for groups 5 to 9, periods 5 and 6. They nevertheless have the relatively high electrical conductivity values characteristic of metals.[8]

I intend to add an overview-summary content for this section, as insightfully requested by YBG, and I'll need as many bubbles as possible—however they're presented—in order to draw the threads together into a coherent narrative. Sandbh (talk) 08:07, 7 August 2021 (UTC)

The swaths of colors show the contrast you are getting at as well as - or I would say, much better than - the chartjunk dashed line currently present. Please remove this unsightly line; I think it actually has the potential to distract the reader from the very thing you are trying to display. YBG (talk) 06:56, 11 August 2021 (UTC)

The dashed line is mentioned twice in the lede to the Notes section, and in the bubble L note, and by implication in the bubble G note. It's notably similar to the dividing line between metals and nonmetals commonly seen on periodic table, as mentioned in the lede. It's relevance is thereby established. I feel that what is one person's chart junk is another person's navigation guide. However, I'll post a chart here without a dashed line for comparative purposes. Sandbh (talk) 07:54, 11 August 2021 (UTC)

​​As promised: 1. with dashed line; 2. without dashed line; 3. with thicker dashed line. Sandbh (talk) 01:43, 17 August 2021 (UTC)

• Yes remove. As described below. It is cluttering (bad graphics), and even when it would be well-described, unintelligible on its meaning or importance (bad content). Absence of metalloids class is not clarified. Reason of showing "metal ... nonmetal" trend related to article topic unclear. -DePiep (talk) 14:09, 18 August 2021 (UTC)

Dashed line evaluation

Which is better? (1) Dashed line (2) No dashed line (3) Thick dashed line. YBG (talk) 03:57, 17 August 2021 (UTC)

@Double sharp, Petergans, and Sandbh: Any more opinions? The consensus so far is to remove the dashed line. YBG (talk) 20:49, 26 August 2021 (UTC)

• (2)>(3)>(1). Additionally, I would say that if one insists on the dashed line, it needs to be consistent, it only surrounds some of the blue/green triangles. It should either surround all such triangles or none. But better still, remove the dashed line completely. Whatever is being shown by the dashed line can just as easily be described in words about the blue-green-purple sea in the upper right corner and the green sea in the lower middle. YBG (talk) 03:57, 17 August 2021 (UTC)
• (2). No dashed line is best (unless a more superiour presentation can be found - after we know what is it supposed to present). From current article version. First of all, it takes decyphering (homework) as it is not explained at all. Second, as far as my homework can tell, the supposed demarcation metal-nonmetal (sic) is broken in two ways: one out of three "nonmetal" anion colors, green, flatly appears on both sides of the ~line. (makes the reader wondering: why Sb, Rn but not all the others?). Second, by the diagonal devider a single element appears on both sides (5 elements). Further, in the corner right-below there is a out-of-elements use that seems to say that "group 1–17 are cationic; group 18 are anionic". Most troublesome in graphics is the arrows, which are not explained and which do not create any understandable effect. This is beyond homework. If it is graphically this complicated to create, and its is content is doubtful or unspecific wrt the title, leaving it out here would help the periodic table presentation, from chaotic to better-aimed. -DePiep (talk) 16:34, 17 August 2021 (UTC)

I add to this: the dotted line introduces(!) the need or cause to create an extra island of "nonmetals" in the d-block (Nb, Ta ... Ir). An indication that "anionic" and "nonmetal" do not overlap significantly. There is also the reversed logic here (ouch): "[this island] is an exemplar for the reputation many transition metals have for nonmetallic chemistry". So first it is used to base that anionic is nonmetallic, then that same fact is reversed to claim that they have an, eh, 'reputation'.

Then there is the definition. Per § Notes: "in the p-block ... dividing line between metals and nonmetals, and metalloids"?! How can a single line distinguish three (unmarked) classes?

More and more this supports the impression that the divider metal-nonmetal is irrelevant for this article. Where does it come from anyway? It is not supporting any serious claim of connection between non-metallishness and being aniodic, nor does this article's statements (the List) follow from being nonmetallic etc. Also, it is factually leaving metalliods out of the view (though mentioned inconsequential as a sidenote) without considering their possible influence. -DePiep (talk) 14:00, 18 August 2021 (UTC)

• Keep the dashed line, or superior graphic equivalent per User:DePiep, with white borders around the element cells. Consistency issues to do with the path the line takes can easily be addressed. I've written extensively here about what the line shows. If it remains a mystery this can easily be rectified with accompanying text. The arrows make it easier to navigate the path of the line. Again, this is a design issue rather than a let's throw the baby out with the bathwater issue.

Recall the article started with just the PT, including the dashed line, the aim being to show a line of demarcation between elements with metallic chemistry and those without. The fact the several of the transition metals have a nonmetallic chemistry rather than a metallic chemistry, is remarkable. The fact the line resembles the traditional dividing lines between metals and nonmetals is also remarkable and lends credence to the latter. The dividing line between metals and nonmetals can be found on periodic tables all over the world. Why then does the presence of such a line, in whatever form, cause so much angst here? Why is it thought necessary to hide this knowledge, and make it harder for readers to discern the pattern? Sandbh (talk) 08:05, 28 August 2021 (UTC)

Sandbh writes: Keep the dashed line, or superior graphic equivalent per User:DePiep ???. Above I stated and argued that the dashed line should be removed. -DePiep (talk) 08:11, 28 August 2021 (UTC)

DePiep: That's right. You also started off saying:

"No dashed line is best (unless a more superiour presentation can be found - after we know what is it supposed to present)."

Hence what I wrote. Sandbh (talk) 08:25, 28 August 2021 (UTC)

A misrepresentation. "keep the dashed line" is the opposite of "a more superior presentation". -DePiep (talk) 08:29, 28 August 2021 (UTC)

• (2) I get that the metal/nonmetal distinction is observable at a macro level, but when it comes to cationic vs anionic chemistry, it somehow doesn't seem so impressive. Let me ask: look at that p-block in the picture, with lots of chemically weak metals like Be, Al, Zn, Ga, Sn, Bi, Po showing significant anionic chemistry. I ask: would the reader, trying to split cationic from anionic chemistry, necessarily draw a dotted line in exactly that place? Personally, I doubt it. Why does polonium get the line drawn through it when it has a real cation Po²⁺ (probably), but not tin with Sn²⁺? The rough correlation between cationic aqueous chemistry and metallic physical behaviour is noteworthy, but the transition is so vague here that I do not think drawing the line is a good way to show it.
• (And okay, iridium's aqueous chemistry is clearly not that of a "traditional high school metal" like iron, but I don't think it's really that much like a "traditional high school nonmetal" either.) Double sharp (talk) 10:20, 28 August 2021 (UTC)

Of the five active editors on this page,

• Three (YBG, Double sharp, DePiep) recommend that the dashed line be removed
• One (Sandbh) is in favor of retaining the dashed line
• One (Petergans) has not expressed an opinion

While not unanimous, I believe this is reasonable to declare this a consensus to remove the dashed line. YBG (talk) 16:08, 30 August 2021 (UTC)

 Resolved YBG (talk) 03:17, 2 September 2021 (UTC)

Summary

The consensus of these discussions is

• The periodic table displayed in this article should use white borders between and around the cells
• The dashed line should be eliminated from the periodic table

 Resolved YBG (talk) 22:19, 15 September 2021 (UTC)

Headers

The current table headers are inadequate; there must be a distinction between an hydroxy- species such as Be(OH)⁺ and an oxy- species such as VO³⁺. The chemical formulae show this clearly. The same applies to anions. There are also mixed species such as VO(OH)⁺ for which the old headers were OK. Petergans (talk) 09:55, 22 August 2021 (UTC)

@Petergans: Good point. I've fixed that now. YBG (talk) 22:05, 22 August 2021 (UTC)

@Petergans: Have we adequately dealt with this? YBG (talk) 07:02, 26 August 2021 (UTC)

@Petergans: Are the existing headers and columns adequate in your opinion? As you are the one who raised the issue, it would really help to have your evaluation of the current situation. YBG (talk) 03:22, 2 September 2021 (UTC)

I think that the current version is very unsatisfactory, mainly because the table serves too many purposes at the same time. Secondly, the selection of species to include needs to be much more nuanced. I've prepared a revised version, with more introductory material, in my sandbox, but I'm hesitating about replacing the current table. Your opinion will be appreciated. Petergans (talk) 13:25, 2 September 2021 (UTC)

@Petergans: This section relates your comment

The current table headers are inadequate; there must be a distinction between an hydroxy- species such as Be(OH)⁺ and an oxy- species such as VO³⁺. The chemical formulae show this clearly. The same applies to anions. There are also mixed species such as VO(OH)⁺ for which the old headers were OK.

There are other issues that merit discussion, but my question here is very simple: Have the headers been revised sufficiently to resolve the concern you expressed about the headers. YBG (talk) 15:17, 2 September 2021 (UTC)

The headers are adequate, but columns 2,3 and 5 serve no useful purpose. Petergans (talk) 15:43, 2 September 2021 (UTC)

 Resolved Resolved as far as the headers go. YBG (talk) 16:27, 2 September 2021 (UTC)

Good point YBG. Changing table structure is not the topic here. Must say, the Petergans changing table is worth considering. -DePiep (talk) 18:16, 2 September 2021 (UTC)

Other issues raised by Petergans should be discussed in separate sections.

1. The table serves too many purposes at the same time
2. The selection of species needs to be much more nuanced
3. The (simple) cation and (simple) anion columns serve no useful purpose
4. The summary of species column serves no useful purpose

I suggest that these issues should be discussed and resolved in separate sections. I plan to return here later and insert links to existing section where these issues are being discussed or new sections where they can be discussed. YBG (talk) 16:27, 2 September 2021 (UTC)

Regarding these issues

1. The table serves too many purposes at the same time
   • Probably true. If anyone has any suggestions, they should be raised in a new thread.
2. The selection of species needs to be much more nuanced
   • No doubt true. Particular issues have been raised and I expect will continue to be raised in specific threads.
3. The (simple) cation and (simple) anion columns serve no useful purpose
   • Petergans has ingeniously combined these two columns and I expect these columns will remain in the table.
4. The summary of species column serves no useful purpose
   • This column has been deleted

 Resolved Consequently I believe there is nothing more to discuss in this section. YBG (talk) 22:16, 15 September 2021 (UTC)

Form of list items

​​​​​​ Another question: which form should be used for the various ions?

1. Formula only: {{chem2|CO3(2−)}} CO2−3

   pro: brief, systematic.

   con: no more info

2. Wikilinked name: [[carbonate]] carbonate

   pro: brief, link to more info

   con: formula hidden

3. Linked formula: {{chem2|CO3(2−)|link=carbonate}} CO2−3

   pro: brief, systematic, link to more info

   con: common name hidden

4. Formula + name: {{chem2|CO3(2−)}} ([[carbonate]]) CO2−3 (carbonate)

   pro: link to more info. Nothing hidden

   con: takes up excess space

There are no doubt more pro's and con's that I haven't thought of. I am at this point ambivalent, but suspect that after hearing what others have to say I will form a definite opinion.

Each of these could also include the color when it is mentioned in the sources. I tend to think it is preferable to include this information when it is available, but would think it should be eliminated if the longest choice (4) were to be chosen. But my main concern here is to reach a consensus on which form is preferable..

!votes re formula/name

Cancelled It is a bit disappointing that no one has bothered to comment here, so I guess we are stuck with the current ad hoc system. YBG (talk) 22:52, 15 September 2021 (UTC)

@YBG: I feel it means you can go ahead and do what you prefer, as per WP:BRD. Sandbh (talk) 01:51, 16 September 2021 (UTC)

Yea, but I really don't have an opinion except that I'd prefer consistency. I was really hoping that others would chime in. YBG (talk) 02:22, 16 September 2021 (UTC)

Sorry I missed this!

The issue is that for many cases (e.g. silicates) there is not one formula. Double sharp (talk) 03:48, 16 September 2021 (UTC)

Oxidation numbers

@Petergans, Double sharp, DePiep, and Sandbh: I am reverting the removal of oxidation numbers by Petergans. If I read this talk page correctly, three of us support inclusion of all oxidation states: DePiep, Double sharp, and I. Petergans wishes to remove some or all of them. If I am mistaken, please correct me here and discuss. YBG (talk) 13:52, 18 September 2021 (UTC)

The basis for my position is that oxidation numbers are irrelevant when there is only one of them for an element. For cations the OS is exactly the same as the number of charges on the ion. Removing such instances is a logical follow-on to [my] having placed entries for each oxidation state for a given element, where there are 2 or more of them, on separate lines of the table. Petergans (talk) 15:26, 18 September 2021 (UTC)

I support the revert by YBG (write "+1" not "1"). I do not see any thread that concludes otherwise. If someone, including Petergans, can achieve consensus for a different thing, then go ahead. -DePiep (talk) 20:27, 18 September 2021 (UTC)

If someone does not know about oxidation numbers and oxidation state, if they see some cases where the column is empty, they might reasonably conclude "this element does not have an oxidation state/number" in the same way that they would conclude that if the (hydr)oxyanion column is blank "this element does not have any (hydr)oxyanions". And if likewise for someone who is not familiar with oxidation state, including both the positive and negative signs reinforces the idea that oxidation state is connected to charge. YBG (talk) 23:28, 18 September 2021 (UTC)

I support the inclusion of oxidation numbers as being helpful to at least general readers. A little bit of redundancy can be a good thing. Sandbh (talk) 06:38, 19 September 2021 (UTC)

 Resolved Consensus is include oxidation numbers in all cases, supported in this section by DePiep, Sandbh, YBG and elsewhere (see § Conclusions re "Table changes") by Double sharp. Petergans opposes this. YBG (talk) 13:52, 1 October 2021 (UTC)

Table changes

Petergans, this edit says in its es: "Moved notes to relevant column of the table", but actually they have disappeared completely (look for the {{efn}} notes). Is that a mistake? -DePiep (talk) 10:51, 11 September 2021 (UTC)

No, it is not. References to an unverifiable source were also removed. Petergans (talk) 11:01, 11 September 2021 (UTC)

OK then. For the record, removed were:

• Ebbing, D; Gammon, SD (2016). General Chemistry (11 ed.). boston: Cengage Learning. p. 771. ISBN 978-1-305-88729-9.
• Butler, JAV (1930). The Chemical Elements and Their Compounds: An Introduction to the Study of Inorganic Chemistry from Modern Standpoints. London: Macmillan and Company. p. 133. ; Hinds, JID (1910). Qualitative Chemical Analysis from the Standpoint of Solubilities, Ionization and Mass Action. Easton, Pennsylvania: Chemical publishing Company. p. 164.
• ref name=Takeno: Takeno, Naoto (May 2005). "Atlas of Eh-pH diagrams: Intercomparison of thermodynamic databases. Geological Survey of Japan Open File Report No.419" (PDF). eosremediation.com. National Institute of Advanced Industrial Science and Technology. Retrieved 7 August 2021.
• Avrorin, VV; et al. (1989). "Electromigration of oxidized radon in aqueous solution". Radiokhimiya. 31 (6): 63–67.

No problem for me. Case closed? -DePiep (talk) 19:35, 12 September 2021 (UTC)

Oxidation numbers. The oxidation number in column 3 carries no information that is not implicit in the chemical formulae or the links to element pages. Previously I had removed all oxidation numbers except those where different oxidation states may to be identified. In actual fact, column 3 is now completely redundant as compounds with elements in different oxidation states are shown on separate rows of the table. I will remove it unless there is a sound objection. Petergans (talk) 07:55, 13 September 2021 (UTC)it

It is true that it can be computed from the chemical formula, but that is a nuisance for the reader. In addition, in come cases, the chemical formula is not given, but just a descriptive term. Without showing the oxidation numbers, it would not be apparent to the reader why we show different ions on different lines without explanatory text. With the oxidation numbers, the explanation is not needed.

It is common in WP to have redundant information. Infoboxes frequently show birth and death dates along with the age. Ordered lists of the tallest mountains or other geographical superlatives frequently show the ordinal so that one can tell at a glance which one is, e.g., the 10th largest/highest/etc, even though that is redundant, one can simply count to see what its order is. And while it is reasonable to assume that every WP reader knows how to count, we should not expect every reader of this article to be able to calculate oxidation state from the chemical formula.

Please do not remove this information from the table. YBG (talk) 04:53, 14 September 2021 (UTC)

PS, you say that you will remove it without a "sound objection". That is not the criterion. The criterion would be a consensus among editors. While I strongly believe that this column should not be removed and I believe my objections are sound, it is quite possible that you may not believe them to be sound. You should definitely not remove it just because you do not find my reasoning to be sound. However, if there is a consensus to remove the information, then I will of course recognize that the information can in fact be removed. I trust that you also respect this principle and will not remove the information apart from a consensus to remove it. YBG (talk) 04:57, 14 September 2021 (UTC)

• Support keeping all oxidation state values in there, per YBG reasoning. It adds information for those reading the table. -DePiep (talk) 05:16, 14 September 2021 (UTC)

What about going back to only showing OS only for elements that have more than 1 of them? Otherwise the info is both trivial and serves no purpose. Petergans (talk) 07:21, 14 September 2021 (UTC)

No support from me. It's not "trivial", it is relevant information. Even when an element has only one OS (one row) in the table, it is not obvious which value it is. Why having to deduct it from a table entry, when the calculation is not straightforward? For example, the OH^x value of − is implicit not visible; and that is for those readers who already know how to calculate the OS from formula. Also, an empty cell says that there is a difference between element Xx (with 1 OS) and element Yy (with multiple, shown OS values) -- while both can have a value say +2. Why the difference?

In general, showing redundant information to support the information presentation is well acceptable. In a periodic table it is quite common to mention element name and symbol and Z-number for each. To remove redundancy here, better merge the two anionic columns because being aqueous is already explicitly present in the formulae, given the OH's. Then again, columns "anionic" and "cationic" can be merged, because the + and − element OS is also present and deductable from the formulae. One step further: in this table mentioning the element (in lefthand columns) is redundant by itself: the element symbol is plainly to see in the formula! Thus, redundancy removed would give us a single line of ions, comma separated: all information is in the formula. In other words: redundancy is nothing bad to present information. -DePiep (talk) 11:42, 14 September 2021 (UTC)

I agree with YBG's reasoning. It is easy to calculate, but having to do so is a bit of a nuisance. I would also argue that it makes the article that little bit more accessible to the layman to leave them there, in exchange for not too much space. Double sharp (talk) 13:18, 14 September 2021 (UTC)

• I have reverted Petergans's [7] since, as has been noted multiple times on this page, redundancy by itself is not a reason for removal. -DePiep (talk) 11:13, 15 September 2021 (UTC)

• Left-aligned: I support the recent change [8] that left-aligns table entries (like formulae). IMO, that is the way the Reader is better served. It is, like, the way one reads the table. -DePiep (talk) 19:30, 15 September 2021 (UTC)

  I too support left-alignment of the formula columns, and a Petergans made the linked change, I presume he does also. I think the OS column would be better centered, but wouldn't make a change there without support from the majority of active editors. YBG (talk) 13:43, 1 October 2021 (UTC)

Enough

• By now and by this, Petergans, you have stressed our wikitogether tolerance to the final limit. It has been explained to once or twice that you are expected to reach consensus for disputed edits. -DePiep (talk) 19:55, 23 September 2021 (UTC)

Conclusions re "Table changes"

@DePiep, Double sharp, Petergans, and Sandbh: Here is a summary of the topics discussed in this section:

1. Reference removal. No conclusion on this topic that I can discern.
2. Oxidation states. Petergans proposed removing OS entirely as redundant information; failing that, to list them only when an element has multiple OS. Consensus (DePiep, YBG, Double sharp, Sandbh in § Oxidation numbers) explicitly calls for including OS in all cases.
3. Left alignment. Majority of active editors (Petergans, DePiep, YBG) approve of left aligning formula columns. Consensus re alignment of OS less clear.
4. DePiep complains about Petergans making wholesale changes without consensus

It seems to me that we have a consensus (a) to include oxidation states every row and (b) to left-align the columns containing chemical formulas. If there are no further comments, I plan to archive this section, but first I want to make a new section summarizing the consensuses reached, documented by links to the appropriate section in the archives. YBG (talk) 13:43, 1 October 2021 (UTC)

@YBG: This is all good for me. Per WP:BOLD, Petergans can make wholesale changes that do not breach previously reached consensuses. If he is reverted than it is up to him (or any other editor) to start a discussion to reach consensus, as per WP:BRD, if he (or another editor) still sees merit in the reverted change. Sandbh (talk) 04:04, 3 October 2021 (UTC)

Separating anions

Petergans separated the anions from the rest of the list, boldly and in good faith. I reverted this as it seems to me that if this article is a "list of aqueous ions by element", then the main list should include, under each element, all such ions. Of course, if a consensus of editors agrees that one of the four species should be removed from the table, I will abide by that decision. YBG (talk) 22:00, 3 October 2021 (UTC) To editors active in this article or talk page: (@Sandbh, Double sharp, DePiep, Petergans, Leiem, ComplexRational, Christian75, Reba16, Droog Andrey, Orengurg1, Arjayay, Ulubatil Hasan, Burzuchius, and Rsjaffe:)

• Please voice your opinion here: Should the anions be included in the main list of ions or in a separate list?
• Consider participating in the other mini-RfC's on this page at §§ Mini-RfC: Row headers​ and Mini-RfC: What is the best way to show oxidation states within each element?

YBG (talk) 10:19, 4 October 2021 (UTC)

!Votes re separating anions

How should anions be treated in the main list? Include in the main table or Move to a separate table?

• Include in the main table YBG (talk) 10:19, 4 October 2021 (UTC)
• Include in the main table Sandbh (talk) 09:25, 4 October 2021 (UTC)
• Support revert. -DePiep (talk) 15:04, 4 October 2021 (UTC)
• Include in the main table Droog Andrey (talk) 18:44, 4 October 2021 (UTC)
• Include in the main table Leiem (talk) 02:03, 5 October 2021 (UTC)
• Include in the main table ComplexRational (talk) 19:12, 5 October 2021 (UTC)
• Include in the main table (I'm persuaded). Double sharp (talk) 03:11, 6 October 2021 (UTC)

Conclusion re separating anions

It appears we have a strong consensus to include the anions in the main table. YBG (talk) 03:18, 6 October 2021 (UTC)