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A navigation aid for Wikipedia, based on the periodic table

Prior version, OP time: navbox, 32-column. Current version: Template:Periodic table (navbox)

How about discussing navigation aids? The present one, seen on the information box for every element (look at Neon for example) is arguably too wide for easy use. It has 32 columns and as a result provides only tiny boxes for people to use to link to other elements that they may wish to jump to next. I'd like to make a proposal for a new navigation aid of 18 columns, as below. Astute readers will realise that this also has something to do with the debate we have recently been having on this page!

New version 1

Michael D. Turnbull (talk) 09:49, 21 July 2020 (UTC)

But isn't this clearly a Lu under Y table? And surely that will mean the arguments opposers have used above are still valid against this one? Double sharp (talk) 09:54, 21 July 2020 (UTC)
For the avoidance of any doubt, should we use a 18-column table, could we have a small gap where lanthanides are supposed to be, like in {{periodic table}}?--R8R (talk) 10:00, 21 July 2020 (UTC)
OK, so we could have "a nothing at all under Y" table, as version 2. Personally, I never understood why the Wikipedia tables have the lanthanides and actinides as a separate strip but without including those elements in that strip! Version 2 is more like IUPAC.
New version 2

Michael D. Turnbull (talk) 10:42, 21 July 2020 (UTC)

Yeah, I think this * form is best for Wikipedia. It is at least as close to neutral as you'll get, and it has the argument "well, that's what IUPAC shows now; we know they plan to change it, so we will change it only when they do". We can sweep the 32-column problem under the rug by simply not using the 32-column form much. What you say about La and Ac is indeed one scientific objection I have to the La form, but, again, the important thing on WP is probably not the scientific arguments. Double sharp (talk) 11:24, 21 July 2020 (UTC)
I think we should keep our -La-Ac form there. For one reason that trumps all other possible reasons combined: we need to be consistent about our PT layout. If our layout is -La-Ac, or -*-**, or -Lu-Lr, then so be it.--R8R (talk) 18:43, 21 July 2020 (UTC)
I agree with Michael D. Turnbull that the current 32-column form is too wide and provides only tiny boxes. I agree with R8R that we should keep our -La-Ac form there. Sandbh (talk) 00:56, 22 July 2020 (UTC)

Ah, now we are getting somewhere! What we were all forgetting is that a wiki page is not the same as a printed page. We have the luxury of being able to link cells in the navigation table to anything we like AND give a hover-over message that's appropriate. This is very useful when filling in the contentious cells that IUPAC places asterisks in. We can do better..... see my third and final suggestion below. For the avoidance of doubt, I've added back the usual table legend at the bottom and, yes, I would add a blank row between the main body and the Lanthanide/Actinide strip, if only I could work out how to do so. Note what happens when you click on the cells now below element Y: it's not the same as the click on the words "Lanthanides" or "Actinides" at lower left.

New version 3

I don't think we need any more full versions to discuss the issue and find a consensus for this navigation table to replace {{Compact periodic table}}. We just need to agree a) the colours - I see no need to change; b) the short text where I've currently got La em-dash Lu; c) the Hover-text (I think this has to be the page name that the click will link to) and d) the correct wikilink-on-click Michael D. Turnbull (talk) 09:16, 22 July 2020 (UTC)

I still consider this best for Wikipedia. It will have the argument "IUPAC gives it" behind it in case anyone complains. It will also be neutral in the sense that neither Sc-Y-La aficionados nor Sc-Y-Lu aficionados will be terribly happy. Then a footnote can be added in saying "The elements of group 3 below scandium and yttrium are disputed. Some tables put lanthanum (La) and actinium (Ac) in these positions, while others put lutetium (Lu) and lawrencium (Lr) there. Hence we show a compromise form with all lanthanides and actinides placed under yttrium, as does the current IUPAC periodic table. A IUPAC project was started in 2015 to decide the question."
Now, it does make the scientific statement that group 3 has 32 elements in it. That is indeed scientifically a pretty strange view given the properties of the actinides. However, that is precisely what was done in the JWP (IUPAC-IUPAP) report on the discoveries of Nh, Mc, and Ts.


The evidence is clear: IUPAC in its publications supports this view. People rarely do, of course. But as long as the debate rages and IUPAC has not decided on a form, I support Michael D. Turnbull's proposal: Sc-Y-* and 18-column until IUPAC makes up its mind. Maybe it is not neutral because Sc-Y-* is itself a side, like I said. But you will never find anything more neutral than to follow IUPAC when chemists cannot agree. Double sharp (talk) 10:13, 22 July 2020 (UTC)
At Michael D. Turnbull's request on my talk page, I have added my proposed footnote above as hovertext for the cells reading "La–Lu" and "Ac–Lr". Also a blank row between the main body and the footnote. Double sharp (talk) 11:46, 22 July 2020 (UTC)
Could we please please please stick a single layout and use it consistently in en.wiki? As far as I am concerned, the question of whether it should be -La-Ac, -*-**, or -Lu-Lr is less important than whether we use a consistent format or not (we definitely should). If there really is that much appetite for using a different format than what we use at {{periodic table}}, then please let us discuss a change that concerns all periodic tables, not just the one in element infoboxes.--R8R (talk) 14:57, 22 July 2020 (UTC)
I absolutely agree! The template for {{periodic table}} is, however, enormous and I hesitated to inflict it on this thread. You may not be aware that the template used in the infoboxes at each element page is very much based on what we're discussing here, which as you know goes at the foot of each article. It gets some clever tweaks that highlight the element in question in the periodic table when used in the infobox. So, once we have settled the current discussion and found a competent volunteer who is familiar with template documentation and won't mess up the implementations (that ain't me!) all relevant en.wiki templates should be done. If you feel a separate discussion is needed for {{periodic table}}, please start one, or sandbox ideas to link here (the template has its own sandbox for that purpose). Michael D. Turnbull (talk) 15:13, 22 July 2020 (UTC)
R&R kindly sandboxed something like version 3 at this link but for the moment I don't think we need to take this further. When the dust settles on the current discussion and moves to implementation, we'll certainly keep consistency between templates. Michael D. Turnbull (talk) 17:14, 23 July 2020 (UTC)

There are several things to consider here. [start of comment by Sandbh 23:42, 23 July 2020 (UTC)]

1. There is no such thing as an IUPAC recommended or endorsed periodic table. The table that appears on their website is used within IUAPC. A spokesperson has made it clear that IUPAC does not recommended or endorse any form of periodic table (Leigh 2009).

  • Leigh, J.: Periodic tables and IUPAC. Chem. Int., 31, 4–6 (2009)
Not worth fighting over this but Leigh seems to have changed his mind by 2019, in preparation for IYPT. "In conclusion, IUPAC was not involved in the development of the Periodic Table, but .... it has been the prime international authority for developing and adopting changes in its content ...." see Leigh, G.J. (2019). "IUPAC and the Periodic Table". Chemistry International. 41: 6–9. doi:10.1515/ci-2019-0102. S2CID 126911180.. Maybe in 2019 he only meant content, not the format but if so he didn't make that clear in his article. Michael D. Turnbull (talk) 17:33, 23 July 2020 (UTC)
@Michael D. Turnbull: The development and adoption of changes Leigh was referring to included, "new elements, and their atomic numbers, names, symbols, and atomic weights."
Nor does IUPAC prescribe which elements, for example hydrogen and helium, belong in which group. All they have done is recommend collective names for like elements e.g. chalcogens (oxygen, selenium, selenium, tellurium, polonium) and noble gases (helium, neon, argon, krypton, xenon, radon). For example, if helium is placed over beryllium then helium still belongs to the noble gases.
IUPAC does not recommend or approve any particular format of periodic table or system, nor does it mandate the composition of Groups.
To this end, Scerri (2020) writes:
"The fourth possible presentation is one that abstains from specifying which elements belong in group 3 or rather it is a presentation that only contains two elements, scandium and yttrium, as being definitely in group 3. This table is sometimes labelled as the official IUPAC periodic table although a leading IUPAC official has clearly stated that this organization does not currently support any particular version of the periodic table and that has only concerned itself thus far with numbering 18 of the groups of the table."
Scerri E 2020, "Recent attempts to change the periodic table", Philosophical Transactions A, 378: 20190300, in press.

--- Sandbh (talk) 23:42, 23 July 2020 (UTC)
@Sandbh: ;-) I'm not advocating for IUPAC. I just find it amusing that they want to police all the cells in the periodic table (i.e. the list of contents you mention above) but are apparently agnostic about the architecture of the prison in which these cells fit, despite showing one ugly logo-ridden "prison" on their website. Let's stick to discussing the things we can control, which is what Wikipedia uses as its navigation boxes and other templates. Michael D. Turnbull (talk) 09:18, 24 July 2020 (UTC)
@Michael D. Turnbull: I see nothing amusing about it. Someone has to do it. Who better than the international body for chemists. When you say "Let's stick to…", in the context of so few exchanges of perspectives, I get quite annoyed. I'd prefer that you not presume my support for your view of what "we" should do next. Why would IUPAC want to get involved in the architecture of the prison? Would groupthink in this matter be a good thing? To the extent that anything is under control in Wikipedia, control of the navigation boxes and other templates falls within the purview of WP:ELEMENTS. To that end, you may wish to consider becoming a member of our project. Sandbh (talk) 13:15, 24 July 2020 (UTC)
@Sandbh: The issue is what the "it" is. If one means "settle the dispute about group 3", then IUPAC has a role. If one means "choose which form of the periodic table people must use" that clearly would be groupthink, as DePiep you put very eloquently later in this thread (on bookburnings). On Wikipedia I like to WP:AGF and just get on with the task in hand where the "it" is to build a better encyclopedia. I would be a poor member of the WP:ELEMENTS project because I have expertise only in a tiny proportion of them and none at all on the group 3 question. That still won't prevent me chipping in if I think it worthwhile. Michael D. Turnbull (talk) 14:17, 24 July 2020 (UTC)
@Michael D. Turnbull: There is no dispute about group 3 within the chemistry community. A few (relatively speaking) people have suggested Lu looks better under Y (ignoring the background to, or features of, La under Y). Jensen had a red hot go in 1983, and failed to gain traction. Scerri, who is chair of the IUPAC Group 3 project described Jensen's arguments as being too selective. Just because there is such a project does not mean IUPAC will take any notice of its report or recommendations. You have no understanding of the politics, history and culture involved. You are more than welcome to chip in here at any time. Please do not do so after the fashion of a WP:BICS bull in a china shop. People in our project have been discussing the group 3 project for several years. That does not mean they are right. It does mean they know quite a bit about the situation. Sandbh (talk) 06:31, 25 July 2020 (UTC)

2. The IUPAC table is now especially "bad" since they deliberately misaligned the 15-element wide f-block purely so that they could fit the IUPAC logo in.

3. The 18-column *-** form results in the f-block becoming part of the d-block. This is so bad that Jensen (2008) referred to it "chemical nonsense" and that, "IUPAC or not, I can hardly believe that a modern inorganic chemist would advocate such an antiquated interpretation of these elements, unless, as noted above, they have lost all contact between the underlying premises of their periodic table and the facts of chemistry." Disclaimer: While I agree with Jensen in this case, I disagree with his position on Group 3.

  • Jensen WB 2008, "The Periodic Table: Facts or Committees?", Journal of Chemical Education, vol. 85, no. 11, pp. 1491−1492

4. Using the *-** form is not consistent with the literature. Thus, Mathias (1969) grumbled about La in group 3 being the most popular form. Myers, Oldham and Tocci (2004, p. 130) found La and Ac to be the most popular form of periodic table, a sentiment echoed by Clarke and White (2008); and Lavelle (2008; 2009).

Clark RW & White GD 2008, "The flyleaf periodic table", Journal of Chemical Education, vol. 85, no. 4, p. 497
Lavelle L 2008, "Lanthanum (La) and actinium (Ac) should remain in the d-block", Journal of Chemical Education, vol. 85, no. 11, pp. 1482–1483, doi: 10.1021/ed085p1482
—— 2009, "Response to misapplying the periodic law", Journal of Chemical Education, vol. 86, no. 10, p. 1187, doi: 10.1021/ed086p1187
Mathias BT 1969, "Systematics of superconductivity", in PR Wallace (ed.), "Superconductivity: Proceedings of the Advanced Summer Study Institute on Superconductivity", McGill University, Montreal, vol. 1, Gordon and Breach, New York, pp. 225−294
Myers RT, Oldham KB & Tocci S 2004, Holt chemistry, Holt, Rinehart and Winston, Orlando

5. A survey by the IUPAC Group 3 project team found that the majority of textbook and other periodic tables in the 18-column format show the elements of group 3 as scandium, yttrium, lanthanum and actinium. The survey did not include a Google image search, since such results are plagued by bias arising from the false impression that the IUPAC *-** table is “official”, and unreliable sources.

6. As R8R noted, "consistency with literature is of the uttermost importance for Wikipedia if literature itself shows such a consistency; Wikipedia is meant to be a tertiary source."

--- Sandbh (talk) 01:19, 23 July 2020 (UTC)

  • Version 1 and 2 have this omission: the bar below is not representend in the main table, there are no placeholders (usually asterisks). One cannot see where the bar below is supposed to be. Also, there is not extra separator (like whitespace) between the main table and the bar below. This suggests says that the bar below is part of the main table.
Version 3 says that the bar below is in total below Sc, Y. Thus, Sc and Y and group 3 all stretch 15 columns. -DePiep (talk) 06:14, 23 July 2020 (UTC)

Please focus now on improving version 3

Yes, versions 1 and 2 are now superceded by version 3, which is all we need to discuss beyond this point. I will update the current version 3 in the thread as we appear to reach any new consensus about it. Personally, I'd be happy if the "hover-over" on the cells under Y didn't mention IUPAC as we are creating a new standard for en:Wiki, not trying to do the impossible! Is that the crux of your objections @Sandbh:? If so we'll just delete ", as does the current IUPAC periodic table" from the hover-over: which has the advantage of making it shorter for readers, which in the long run could be millions of people. Alternatively, if your objection is that "there can only be one group 3 element below Y", then we'll make the text in that cell "La or Lu" rather than "La—Lu" and again clarify in the hover-over. We would change the colours of the relevant two cells as well, of course. This "or" solution has the huge advantage that Wikipedia's version will now include La in the Lanthanides strip, which was one of the issues I had with our current {{periodic table}}, which doesn't. I have been WP:BOLD and made these changes now, so everyone can see their effect. Incidentally, the IUPAC website today says "The question of precisely which elements should be placed in group 3 has been debated from time to time. An IUPAC project has been recently initiated to resolve the question. Will group 3 consist of Sc, Y, Lu, and Lr or, will it consist of Sc, Y, La and Ac? (My emphasis)" Michael D. Turnbull (talk) 14:37, 23 July 2020 (UTC)
It's not a new standard. Sc-Y-* is exactly what we had up till 2014. Then it got changed to Sc-Y-Lu after some discussion at WT:ELEM back then. And then it got changed to Sc-Y-La after the previous RFC at Template talk:Periodic table. (When I knew less and thought that was scientifically better; now I know more and consider Sc-Y-Lu scientifically better.) So I do not mind if it gets changed to Sc-Y-*. It would just be full circle.
Regarding Sandbh's and DePiep's points:
  1. We have no problem using IUPAC-internal stuff as a compromise even if not everyone outside follows it, viz. the spelling guideline WP:ALUM. In fact that is a precedent for doing it when there are two significant sides that simply do not agree. Going for Sc-Y-La picks a side. A 2/3 majority of textbooks as the survey shows is hardly so much that picking such a side can be considered neutral; if it were 90% that point would be stronger. IUPAC however seems something we can compromise on.
  2. The misalignment is not an issue, the footnote is a footnote regardless of where it is placed. It still means that the same elements go in the same place.
  3. The fact that version 3 says that all the Ln and An are in group 3 is not a problem, as that is how they are indeed considered IUPAC-internally. See the quote above.
  4. The problem I have now with referring to the literature to chemically analyse and be against Sc-Y-*, as Sandbh did, is that in general as I understand we are not supposed to analyse it ourselves for WP. That is treading close to original research. In fact there is another problem, which is that starting to analyse this will inevitably lead to starting the eka-yttrium holy war again. In fact, I did, but thankfully Michael D. Turnbull came by below and on my talk page and knocked some sense into my head. So I remove that text. Sense and focus knocked into my head aside, to avoid this problem I prefer following IUPAC with Sc-Y-* to compromise. Double sharp (talk) 14:54, 23 July 2020 (UTC)
@Double sharp:We are in danger of re-running the Group 3 debate in this thread! Please focus on the issue at hand, which is what do you want an 18-column table to look like? There are only 4 possible parts to alter, as I already pointed out below version 3. They are a) the colours in the cells b) the short text where I've currently got "La or Lu"; c) the Hover-text and d) the correct wikilink-on-click. Surely you can confine your comments to making suggestions specifically for these, without saying much else? Michael D. Turnbull (talk) 15:03, 23 July 2020 (UTC)
@Michael D. Turnbull: My apologies. Thank you for knocking some sense into my head: I removed the old text. I think you will like what is now there instead.
Now the answer. I prefer the old form; AFAIK IUPAC still considers the other Ln and An to be in group 3 even after the project started judging from the JWP reports above. So I read the "or" as meaning that they will eventually decide on one or the other, but right now the old situation of Sc-Y-* is still their form in the interim. More to the point, the colouring of the cells below Y with the Ln and An colour is also on the IUPAC table. IUPAC is a strong and powerful argument for compromise, let's keep it strong by sticking close to what they do. As for tooltips, anything that says there's a dispute, this is the IUPAC-internal form, and IUPAC is looking into it will be fine with me. Precise wording is not a problem. Double sharp (talk) 15:13, 23 July 2020 (UTC)
I have made bold edits, see #Step 1 done below; main OP issue solved. However, other changes mentioned here I object to. Later will have time for arguments. -DePiep (talk) 15:23, 23 July 2020 (UTC)
  • versions 1 and 2 are now superceded by version 3, which is all we need to discuss beyond this point. No. "Superceded" has not been established. Thi subthread, with its non-sequitir ignation, is invalid. Dead on arrival. No need to spend time on this. -DePiep (talk) 23:47, 23 July 2020 (UTC)
​​ Apologies, De Piep, my language was not precise enough. By "supercede" I meant that version 1 and 2 are versions which reflect the past discussions in this thread and should not be changed in any way, so new readers will see where we came from, while version 3 can and will change as we stumble towards a consensus — in that respect it's like the thread's sandbox, so is all we need to discuss (and possibly change) beyond this point. What you have already implemented on the live Wikipedia navigation template in 18 columns largely meets my request for change: and this would be complete when you do the same change on the element infobox version, where the problem of tiny cells in 32-column format is even more acute. Frankly, I despair of reaching a consensus over the group 3 issue and I don't really care: it is irrelevant to navigation. Anyone who wants to fight about this narrow issue is welcome to do so below in this thread but I probably won't engage. My only new contribution has been to point out that the hover-over tooltip gives us a mechanism to point out the controversy without resolving it. Michael D. Turnbull (talk) 09:37, 24 July 2020 (UTC)

​​​I make the following observations: The spread is 4:1:1, where Sc-Y-La-Ac is four times as common as either *-** or Lu-Lr. This is nowhere near any degree of ambiguity sufficient to justify a judgement call or compromise. Going for Sc-Y-La does not pick a side. There is no finely balanced contest of sides.

The misalignment of the IUPAC table is an issue in that it prioritises vanity branding over the alignment of the early Ln and An with their 5d analogies. Yes, the perception of such "stupidity" is circulating within the chemistry community.

Nobody takes account of the strong resistance IUPAC has to making recommendations on group composition or the form of periodic table. For example, if the IUPAC recommends group 3 as La will this render the Janet table as being politically incorrect or wrong-headed thinking? No doubt the IUPAC would have to set up re-education internment camps for Lu supporters. Next to be labelled as deviant will be Group 14 in the Earth Scientist’s periodic table being composed of carbon, silicon, titanium, zirconium, and hafnium rather than the standard set of carbon, silicon, germanium, tin, and lead. Book burnings to follow.

Once the Group 3 project has made its report there is no guarantee the IUPAC will accept it. If it is released it will go to the chemistry community for consultation. Even then there is no guarantee the IUPAC will turn the report into a recommendation.

La or Lu, plus La-Lr breaches the maxim of one element one place.

The place for accommodating the variants of Group 3 is in the main body of our periodic table article, as we do now. Here we write that, "Although scandium and yttrium are always the first two elements in group 3, the identity of the next two elements is not completely settled. They are commonly lanthanum and actinium [by a wide margin], and [significantly] less often lutetium and lawrencium." (my brackets)

Just so. --- Sandbh (talk) 00:24, 24 July 2020 (UTC)

I do not agree that the important figure is 4:1:1. The IUPAC survey breaks things down by decades, and you can see that the La form is steadily losing its majority since the 1990s:
Decade La under Y Lu under Y * under Y Total
1970s 18
69% 		2
8% 		6
23% 		26
1980s 31
78% 		6
15% 		3
8% 		40
1990s 27
82% 		2
6% 		4
12% 		33
2000s 38
62% 		14
23% 		9
15% 		61
2010s 16
48% 		6
18% 		11
33% 		33
As you can see, by the 2010s La has lost its majority. I guess the reason is WebElements becoming popular and supporting Lu, though I have no source for that. For this reason I think * would be more justified to show for neutrality. Double sharp (talk) 02:45, 24 July 2020 (UTC)

@Double sharp: Why are you engaging in WP:FORUMSHOPing? You have posted the same content to our project page. Please confine your argument to one forum. And where is the hyperbolic language coming from? It is like there are two of you: one who is calm; the other one who is foaming at the mouth. Sandbh (talk) 06:48, 24 July 2020 (UTC)

@Sandbh: It seems relevant to both places since the 4:1:1 dominance has been discussed in both places. If you want, I can delete it from the project page and discuss it only here as it seems more relevant for this decision. I have replaced the old text with text from the WT:ELEM page.
Let me just say regarding your comment there: I do not think we should drill down into where the increase in * and Lu figures are coming from. You say at the project page that probably * comes from a mistaken view of IUPAC and Lu comes from Jensen (who you then refer to Scerri and Parsons to criticise); that's all fine and well, but I could very well also say that the huge figures in favour of La in the earlier decades come from the debate being poorly publicised and most authors being unaware that a dispute existed at all (for which I can refer to Jensen saying in 1982 that no chemists he talked to were aware that the dispute existed, and indeed that he was not aware of it till shortly before he published his article). That's the problem: both sides can say "that's not so suggestive because X" to counter the other one. I think that's exactly the sort of situation that demands simply looking at what the sources say and not trying to second-guess why they chose as they did, if we want neutrality.
But all in all, I don't really care that much anymore, as long as it cannot be Lu. I have no strong feelings about whether Sc-Y-La or Sc-Y-* is better than the other. Double sharp (talk) 08:04, 24 July 2020 (UTC)
Sigh. -DePiep (talk) 20:11, 24 July 2020 (UTC)
  • @Michael D. Turnbull, Double sharp, Sandbh, and R8R: If I understand this well, this is a proposal to present the PT with a different group 3 constitution (actually an "OR" setup) than we present until now, while not changing other general PT graphs this way. I see two major problems with this:
Problem 1: This would introduce different presentations in general PT graphs. ("general" means non-specific topics, i.e. the basic presentation). I see no reason to introduce these forms, over our current policy to have one preferred version.
Problem 2: It redoes the group 3 discussion in a side-place (just a navbox). However difficult to conclude the main talk, we cannot create backdoor-decisions. If we want to present group 3 in an "or"-form in general (or, in the IUPAC-form of 32 elements ouch), that should be an explicit proposal.
-DePiep (talk) 10:41, 25 July 2020 (UTC)
Not as far as I'm concerned as the OP. I just wanted to suggest changing the 32-column hard-to-use navigation boxes into 18-column ones and I made a proposal. I inadvertently got dragged into a Group 3 battle which in the context of this sub-thread breaches WP:NOTAFORUM. I'm very pleased with what you've already done as Step 1 and will remove myself entirely from the sub-thread once Step 2, the corresponding change in the navigation box used in the Infobox of each element, is also done. I assume you could do it now, although I appreciate it may be a lot of work for you and requires a consensus that the change is sensible: which actually I think already exists. Michael D. Turnbull (talk) 10:56, 25 July 2020 (UTC)
  • Minor problems with #New version 3. (Minor = not involving a group 3 decision; should be solvable by graphical/textual means).
A. Background color cells "La or Lu" and "Ac or Lr" now is says "Transition metal", I guess Ln, An colors are expected there.
B. The bottom bar (I do not say 'footnote', as footnote is a textual detail or comment while here the bar is full part of the table), the bottom bar cannot be rendered unambiguously into the main table. There is no clue as to where it should end up. It would leave the reader with a puzzle. As we know, there can not be a difference between a 18-column PT and its equivalent 32-column form.
C. It reintroduces the category names "Lanthanide" and "Actinide" spelled out inside the table. We have maintained since long that we do not add category names inside the table at all. Keeping these gives the LNs and ANs a special status, adding complexity without reason. (If there were one category to be named, it should be metalloids first as that is a major deviding set, in the metal=metalloid-nonmetal trend).
D. Currently {{hover title}} is used to describe & explain the "or" issue. However, using tooltip texts this way is bad practice. WP:Accessability says Do not use techniques that require interaction to provide information, such as tooltips or any other "hover" text. [{{abbr}} is the exception] See for example issues with title: not available in mobile devices, not working well with screen readers. The information better be provided in a textual footnote.
Most of this stems from the desire to present two group 3 forms; making a choice in this first would help better. -DePiep (talk) 11:04, 25 July 2020 (UTC)
The choice is effectively already made, as in the current {{periodic table}} and new live 18-column navbox. I am happy to agree with your technical views on the implementation for the element Infoboxes and give up on the other ideas as being unworkable, bad practice, or impossible to gain consensus. There is no need to present two group 3 forms and I'm happy to stick with Wikipedia's current implementation: I believe that even ^_^ accepts this for now. Michael D. Turnbull (talk) 11:22, 25 July 2020 (UTC)
@Michael D. Turnbull: Indeed, I do. Double sharp (talk) 11:38, 25 July 2020 (UTC)
OK, so we stay with the status quo? I could not detect that from this thread, but fine with me. Of course, a group 3 conclusion would be welcome. -DePiep (talk) 11:41, 25 July 2020 (UTC)
continued in #Micro PT in infobox below. -DePiep (talk) 22:29, 25 July 2020 (UTC)

Micro PT in infobox

Split from previous section
Well, not the status quo where readers of Neon see a difficult-to-use 32-column presentation in the Infobox but a new status quo where they see an 18-column one instead. The detection was difficult owing to the WP:NOTAFORUM stuff and my lack of knowledge that a tooltip is not a place to add information. Michael D. Turnbull (talk) 11:49, 25 July 2020 (UTC)
I am surprised to read that this seems to be the topic of this thread. So somewhere it is noted that the micro PT {{Periodic table (32 columns, micro)}} would improve in 18-column form? (I don't think so btw). Please describe what the difficulty is, if that's not done before. -DePiep (talk) 12:31, 25 July 2020 (UTC)
That's precisely what I said in the second sentence of this thread. I went on to use the template that's used at the bottom of all element pages for navigation for the purposes of starting the discussion because a) I thought the Infobox one was based on the bigger one b) I wanted to make a specific proposal so we could start a discussion c) my (limited) skills at editing templates meant it was easier to sandbox my ideas in the bigger one and d) I assumed that whatever we decided for the bigger one would be applied to {{Periodic table (32 columns, micro)}} since that's the one that I and presumably others have most difficulty actually using for navigation: the cells are simply soo small to accurately put a cursor on the correct place when you want to click onto another element's article. I now see that I should have started the thread by making a proposal to replace {{Periodic table (32 columns, micro)}} with {{Periodic table (18 columns, micro)}}, which already exists, in element Infoboxes. That's a much simpler proposition! I didn't at the time of starting this thread realise that 18-micro PT existed.... I'd still like to discuss and implement that change, so indeed a new thread may now be the best way forward now that you have already done Step 1. Michael D. Turnbull (talk) 13:11, 25 July 2020 (UTC)
It's just that this thread started multiple issues at the same time. About this one: it is called 'micro' for a reason; usage in the infobox (and other places [1] 500 in total) is to illustrate a position in the PT, not chiefly a PT navigation box. As it happens, the 18-col variant has equaly sized cells ;-). 18 columns introduces this drawback: the reader is supposed to mentally reposition the bottom bar (LN, AN), like building an IKEA cupboard. This complication is unneeded, and undoes the "PT overview" aim. -DePiep (talk) 15:55, 25 July 2020 (UTC)
Yes, I see how the thread muddles several issues. I agree that the primary aim of the infobox version is to locate the element and in some respects it is unfortunate that it actually behaves like a navigation box at all. It might be better that a hover over the tiny cells gave the name of the remote element but couldn't be used to jump to that element's page (reserving this functionality for the larger navigation box at the foot of the article). Anyway, that's not worth a discussion nor a change and as a result I suggest we close this thread: thanks so much for your help in doing the implementation of what we did agree. I won't post here again unless pinged. By the way, I'm surprised that no-one seems to have used {{Periodic table (18 columns, micro)}} anywhere in the main encyclopaedia, as that version is a very compact display of the whole table in a format that will be more familiar to most chemists than the 32-column counterpart. I'm going to put it on my user page! Michael D. Turnbull (talk) 16:10, 25 July 2020 (UTC)

Step 1 done

(ec) I have made these edits boldly:

  • Per original Original Post by User:Michael D. Turnbull first issue, stating that 32-columns is arguably too wide for easy use, esp on smaller screens: I have reformed the format into an equivalent 18-column Periodic table.
Note that this does not change the described constitution of group 3. The background is that the enwiki Periodic tables are explicitly supposed to reflect the same PT consistently, basically the one per Periodic table, except when the topic is a deviation (for example, Periodic table#Placement of hydrogen and helium).
  • I have Moved the template to new name {{Periodic table (navbox)}}, so as to reflect its most important feature: being a navbox (with all its quirks). The old name now Redirects to this one (no visible change or break for articles).
  • However, the OP also states: Astute readers will realise that this also has something to do with the debate we have recently been having on this page!. But exactly the opposite is at hand: the group 3 discussion (both at enwiki and in RL) is not related to the form being 18- or 32-column. For illustration: RFC initator Double sharp has presented, correctly and gently, each of the three options in both their 18- and 32-column form, i.e., six PTs in total.
Also, other changes introduced in this thread (like labeling "lanthanides, actinides" below) are not performed, as these have no consensus (and to be clear, I oppose; more arguments later). -DePiep (talk) 15:20, 23 July 2020 (UTC)

Reverted

I have reverted this change in {{Periodic table (navbox)}} [2], as some editors pointed to a misunderstanding and confusion in this thread. The navbox is back to 32-column format. This does not state any prejudice. New proposals best be made in a new thread. See also #Propose closing as is below. -DePiep (talk) 09:47, 26 July 2020 (UTC)

Next steps

@Michael D. Turnbull, DePiep, Sandbh, and Double sharp: sorry, I haven't been watching the discussion very closely. But did we arrive to the conclusion we wanted? I thought that if we needed to switch from 32 columns to 18 anywhere, it would be the small table in the infobox rather than the one at the bottom of a page. Do we not want to change it instead? Was there really a problem with the table at the bottom of our element articles?

Also, DePiep, on my screen the renewed table looks not only unpleasant (cells have become waay to wide, I can attach a screenshot if you want to look at it) but also strange because some columns differ by their width. Can this be helped?--R8R (talk) 18:21, 25 July 2020 (UTC)

Maybe "not unpleasantly" is a mistake writing, meant to say 'unpleasantly'? I do see this, which is unpleasant indeed: the cells span wide to fill the width of the page (in my wide desktop screen). But: this is the OP request, and I am supposed to live with it ;-). Could yuou describe what you expect, re PT width in this? And to be clear: no error/break happens, right? -DePiep (talk) 22:24, 25 July 2020 (UTC)
@R8R: multiple issues were ignited in this thread. Confusing. The micro table issue (PT overview in element infobox) was one of them, incidentally addressed today above. Later more from me. -DePiep (talk) 22:14, 25 July 2020 (UTC)
Maybed #Micro PT in infobox clarifies. -DePiep (talk) 22:30, 25 July 2020 (UTC)
(copyedited my writing)--R8R (talk) 11:54, 26 July 2020 (UTC)

@DePiep and R8R: I understood R8R and I were supporting an 18-column table at the top of the info-box, and retaining the 32-column table at the foot of each element article. That way the reader gains a sense of familiarity from the 18-column table, then has the "aha" moment at the foot of the page, which shows where the f-block fits into the 18-column table.

The way this proposal was initiated and managed (in good faith by everyone, no doubt) is a text-book example on how not to do it. Sandbh (talk) 07:58, 26 July 2020 (UTC)

More steps

I see that the current discussion has been confused and a new discussion would be much more focused if it was "Lets replace Template:Periodic table (32 columns, micro) with Template:Periodic table (18 columns, micro) in Element infoboxes, making the cells in the latter a bit larger so as to fill the available width of the infobox." I like that format, despite DePiep calling it an Ikea cabinet. I think most chemists are more familiar with that version than the 32-column one. As you !vote, please mention if you support having this new thread, otherwise I won't bother. Michael D. Turnbull (talk) 13:26, 26 July 2020 (UTC)
@Michael D. Turnbull: This is a very unhelpful comment, because is it starts a discussion while the question is Yes/No. The problem *is* unstructured discussion flow. As noted here, arguments could/should be entered in a new thread. It is useless to take shots here at any future discussion. -DePiep (talk) 13:52, 26 July 2020 (UTC)

Propose closing as is

@Michael D. Turnbull, Sandbh, Double sharp, and R8R:

  • Given that this thread has caused much confusion and misunderstandings, I have #Reverted the change in {{Periodic table (navbox)}}, so as to start from a clean sheet. We are now at the status quo ante.
  • I strongly propose to close this thread as is, without any prejudice (i.e., no claims or conclusion be drawn from it), to get rid of all confusion. After that, a new thread can be started preferably from a more simple statement. OK? -DePiep (talk) 09:56, 26 July 2020 (UTC)
!Votes

I request an uninvolved editor to close this thread #A_navigation_aid_for_Wikipedia,_based_on_the_periodic_table as "no consensus" or "procedural close". (per Wikipedia:Closing discussions: # further contributions are unlikely to be helpful). Contributors, including OP, have supported the conclusion that too many issues were discussed intertwined, thereby confusing the threads of argument. This #Propose closing as is invites to restart (from status quo ante, no prejudice) with a more crisp initial question/proposal. -DePiep (talk) 12:07, 1 August 2020 (UTC)

Hi DePiep, please create a report at WP:RFCL. Best regards, ~ ToBeFree (talk) 19:32, 1 August 2020 (UTC)
Done. [4] -DePiep (talk) 16:03, 2 August 2020 (UTC)
More detailed talk on easy closure
  • Hi User:ToBeFree. Your reply was not helpful, actually, for us talkers here :-(.  Core point: the closure proposed is not contentious. So per WP:RFCL#Requesting_a_close (I had read), an RFCL is not needed.
By now my request at RFCL is in a queue, waiting for days to pass by. If only you had seen the obvious undisputed clarity for closure (all in this subsection), and acted followingly, we editors could have moved on with the desired fresh Talk. Even OP @Michael D. Turnbull: supports closing. So my question is: could you reconsider your answer here, reread this subsection, and formalise an uninvolved closure. All to save time and prevent procedureal red tape. Thanks. -DePiep (talk) 22:21, 3 August 2020 (UTC)
DePiep, either there is a need for a closure, and thus a reason for a RFCL request, or there is no need for a closure, and no need for an "admin help" request. ~ ToBeFree (talk) 18:58, 4 August 2020 (UTC)
Well, "thus" is incorrectly used. I quote from WP:CLOSING (I linked before), italics added:

"If consensus remains unclear, if the issue is a contentious one, or if there are wiki-wide implications, a request for a neutral and uninvolved editor to formally close a discussion may be made at Wikipedia:Administrators' noticeboard/Requests for closure."

None of the requirements are met here. Even a WP:NAC is possible. The only requirement is "uninvolved", and that is what I asked for. You were invited to take an outside look & judgement instead of rolling out the red tape, unbased. -DePiep (talk) 19:16, 4 August 2020 (UTC)
DePiep, the place to request an uninvolved closure is WP:RFCL, not {{Admin help}}; probably not even {{help me}} (skipping the queue). If you think the discussion needs such a closure, a noticeboard exists for exactly this purpose, so I've linked to it. The header of that noticeboard also contains advice for other cases, and perhaps this is one that doesn't require formal closure or uninvolved closure. If so, choosing a different way of requesting the same help seems to ignore the underlying reason for not choosing RFCL. ~ ToBeFree (talk) 19:21, 4 August 2020 (UTC)
(ec) re 19:21 post. Admin help comes closest to asking for this undisputed noncontroversial closure. (There is no "NAC-help" request option).
You write advice for other cases, and perhaps this is one that doesn't require formal closure or uninvolved closure -- that is what I am saying, twice+, so you were invited to understand that. If you cannot judge this ("perhaps"), then you should have skipped this request and leave it to others. But since you have engaged, and I ask follow up question, one might expect you to re-judge your acts here. -DePiep (talk) 19:31, 4 August 2020 (UTC)
In one simple quetion: By now, do you think this thread can be closed directly, without WP:RFCL post? -DePiep (talk) 19:31, 4 August 2020 (UTC)
DePiep, with your certainty that the answer is "yes", please just close the thread yourself. ~ ToBeFree (talk) 19:35, 4 August 2020 (UTC)
@ToBeFree: You steer me into closing while involved? I consider this trolling by an admin. -DePiep (talk) 23:00, 5 August 2020 (UTC)

New thread

This is not an invitation for new discussion here, but a pointer to a new thread.

There are two essential issues around here: (1) what elements should be put in group 3 on Wikipedia, and (2) whether the navbox periodic table should be shown in 18 or 32 column format.

As new information has come in (a past IUPAC endorsement of the form with Lu under Y), I have started another thread below: Talk:Periodic_table#IUPAC:_an_endorsement_on_group_3_(1988). This is about the first issue (group 3 composition) only. I have endeavoured to keep it policy-based and drama-free.

To avoid confusing various issues, I suggest that the second issue about 32 vs 18 column be started in another new thread if anyone wants. I don't consider that very important myself, and therefore I have not started it. Double sharp (talk) 03:14, 2 August 2020 (UTC)

Double sharp: is this really an extension to the main thread #A_navigation_aid_for_Wikipedia,_based_on_the_periodic_table? And how would this be a useful, late contribution since there is one conclusion drawn: confusing thread beyond repair? I don't see. -DePiep (talk) 09:40, 2 August 2020 (UTC)
@DePiep: Maybe I did not make myself clear, so let me explain what this is. I agree that this thread covered too many issues and support closing it, which is why this is just a pointer to a new thread (beginning afresh). I mentioned above that there are two major issues that it seemed to be trying to discuss at once: (1) what elements should be put in group 3 on Wikipedia, and (2) 18 vs 32 column format for the navbox periodic table. Therefore, I started a new thread where (1) alone may be discussed. I did not start one about (2) because I consider it relatively unimportant myself, but with no prejudice against anyone else starting one. Does that help clarify matters? Double sharp (talk) 09:45, 2 August 2020 (UTC)
Stop it. Stop this thread. By any means. Again stating "GF" arguments is the problem. -DePiep (talk) 23:42, 2 August 2020 (UTC)
@DePiep: But it is already stopped? I simply meant to say "go to the bottom for the new thread". Double sharp (talk) 02:30, 3 August 2020 (UTC)
The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.


Mendeleev Tabli first edition

According to the final chronology of the first publications of the Mendeleev’s Periodic Table (Druzhinin, 2020[1]), the first Medneleev ‘s Table published March 26-27 [O.S. March 14-15] 1869 in the Mendeleev’s The Principles of Chemistry 1st Edition, and around March 17 [O.S. March 29] 1869 Mendeleev printed separate broadsheets with Periodic table - Attempt - to be sent to overseas scientists; April 17/19 for the first time the Mendeleev’ Periodic table was published in Europe in Journal für Praktische Chemie (in German)[2]

References

  1. ^ Druzhinin, Petr (2020). "The First Publication of Mendeleev's Periodic System of Elements: A New Chronology". Historical Studies in the Natural Sciences. 50: 129–182.
  2. ^ Mendeleev, Dmitri (1869). "Versuche eines Systems der Elemente nach ihren Atomgewichten und chemischen Functionen" [System of Elements according to their Atomic Weights and Chemical Functions]. Journal für Praktische Chemie. 106: 251.

RFC: Should the default form of the periodic table be changed to put Lu and Lr in group 3, rather than La and Ac?

Per consensus to abandon this trainwreck of a thread as-is. (non-admin closure) —Mdaniels5757 (talk) 20:23, 6 August 2020 (UTC)

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

Should the default appearance of the periodic table on Wikipedia be changed to what it was in 2016, i.e. to have lutetium (71Lu) and lawrencium (103Lr) in group 3 rather than lanthanum (57La) and actinium (89Ac)? Or should it simply have markers below yttrium where all the lanthanides and actinides are supposed to go in? Double sharp (talk) 10:08, 20 July 2020 (UTC)

Note for further clarification: this does not propose to treat any form as the only one, because that would contradict WP:NPOV. On this article we must of course discuss both forms and treat them neutrally but briefly, that goes without saying. I simply mean to discuss the appearance of our templates like {{Periodic table}}, {{Compact periodic table}}, the one in the infoboxes like {{infobox helium}}, etc. These normally appear as navigation aids in articles where the group 3 dispute is simply irrelevant, therefore unless someone has a better solution we seem to need to pick a default form for those. Double sharp (talk) 12:44, 20 July 2020 (UTC)
Current RFC withdrawn for a last try at drafting something both Sandbh and I will find acceptable. Double sharp (talk) 08:51, 21 July 2020 (UTC)

The three forms

Lu and Lr below Y. The form I propose, and which we had before 2016.

18-column:

H He
Li Be B C N O F Ne
Na Mg Al Si P S Cl Ar
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba * Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra ** Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
* La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb
** Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No

32-column:

H He
Li Be B C N O F Ne
Na Mg Al Si P S Cl Ar
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og

La and Ac below Y. The current form.

18-column:

H He
Li Be B C N O F Ne
Na Mg Al Si P S Cl Ar
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La * Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac ** Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
* Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
** Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

32-column:

H He
Li Be B C N O F Ne
Na Mg Al Si P S Cl Ar
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og

Markers below Y. The compromise form. IUPAC shows it on its periodic table, but they also plan to change it to one of the other forms. Which one has not been decided.

18-column:

H He
Li Be B C N O F Ne
Na Mg Al Si P S Cl Ar
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba * Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra ** Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
* La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
** Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

32-column (note the stretching of scandium and yttrium necessary):

H He
Li Be B C N O F Ne
Na Mg Al Si P S Cl Ar
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og

Background information by Double sharp

I spent some time making this issue understandable for any bystanders who may want to join in, helped by feedback from User:Dreigorich. As such, here is an explanation in the form of a dialogue. I have tried to keep answers very short. (The first version was a huge wall of text. Now it is not.)

The issue had its most recent reignition on Wikipedia in December 2019 and raged on through Wikipedia talk:WikiProject Elements/Archive 42, Wikipedia talk:WikiProject Elements/Archive 44, Wikipedia talk:WikiProject Elements/Archive 46, and until a few days ago Wikipedia talk:WikiProject Elements. I say "until a few days ago" because that's when I gave up the endeavour as fruitless: nobody seems about to have a change in opinion, and the arguments are raging in circles, and civility has been thrown out the window (and I realise now that I'm partly responsible for that, which I'm sorry for).

At that point we had exactly, among eight participants:

  • one (1) editor in favour of La (Sandbh);
  • five (5) in favour of Lu (myself, Droog Andrey, Officer781, Dreigorich, ComplexRational);
  • and two (2) who at least found the arguments being made in favour of La questionably convincing (DePiep, R8R).

Since the issue was previously decided in an RFC back at Template talk:Periodic table, discussion between me and R8R concluded that going to another RFC would be the best way to propose it be changed back to how it was before the first RFC. Given that that RFC was over three years ago, and one of the main La proponents in it was me, and I've learnt enough new information since then that makes me think that the arguments I was propounding were wrong-headed, I think starting a new RFC is also most reasonable.

In theory one should get a neutral editor to write the background information. However, the problem is that this issue has something in common with many of the disputes at Wikipedia:Lamest edit wars. It is impossible to find a neutral editor to write background information because as soon as she looks at the issue enough to understand the background information, she takes a side herself and is no longer neutral. That is quite unusual given that Wikipedia:Lamest edit wars does not have a category for natural science, much less chemistry. Indeed, the main positive difference between the issue here and the ones over there is that so far there has not been any actual edit warring. Some uncivil remarks when people on either side get fed up, yes, and I am sorry that I have made some of them. But, thankfully, no edit warring.

So I wrote it. Even if I obviously have an opinion and am obviously supporting it with arguments here, I'm at least referring to reliable sources focusing on the issue to do it. If that is still not suitable, then this may at least be considered as a long explanation of my !vote rather than background information.

Questions 1 to 5

Q1: What are you arguing about?

Well, it turns out that somewhere near the bottom-left of the periodic table there's a bit of a dispute about which elements should go where.

Q2: Really? But I thought the periodic table was ancient history chemically speaking.

Yes, Mendeleev's first table dates from 1869. We still haven't sorted everything out, though. There are a bunch of elements that are rather difficult to place.

Q3: That sounds interesting. Tell me more.

In the words of Eric Scerri, "there's trouble at the beginning, middle and end of the periodic table". This RFC is about the middle: the rare earth elements.

Q4: So are you going to tell us what it is already?

It comes down to whether lutetium (Lu) or lanthanum (La) is a better fit for the position under yttrium (Y) in the periodic table. There's also a third form which has all fifteen lanthanides under yttrium, which we did have on WP a while ago, but not anymore.

Q5: Why is this so terribly important? If an element fits well in two places, why not duplicate it in both positions?

This is not generally done by reliable sources, except maybe when making a point. Therefore on Wikipedia we should not start doing it.

Questions 6 to 10

Q6: What about the "markers below yttrium" form? Isn't it a reasonable compromise?

It looks like one, but it is also a side in itself.

I do not support it for two reasons. One is technical. We sometimes use 32 column templates because they fit better as footers, e.g. {{compact periodic table}}, and then this approach becomes really problematic: scandium and yttrium have to stretch to cover 15 columns.

The other is chemical. This form claims that the f-block is a degenerate branch of the d-block and thus by extension that the f orbitals are a part of the valence core, which is simply false for almost all the elements involved (all but Lu and Lr, in fact). Every redox-capable f element (which is almost all of them) is obviously using its f electrons, and even those which are not seem to have some f contribution anyway (see Q22). See Jensen for a discussion. Maybe all the lanthanides are similar enough to fit below yttrium, but can anyone really claim that for the actinides?

Q7: Well, shouldn't we follow NPOV and show all three options all the time then?

That makes sense, and is what I support, when the group 3 controversy is the topic at hand. But usually it is not. Then you have to pick one to avoid going off on a tangent which is not relevant. Below I argue for Lu under Y.

For reasons of brevity, I will hence forth shorten the options' names to:

  • Lu table: Lu and Lr below Y.
  • La table: La and Ac below Y.
  • * table: Markers * and ** below Y.

Q8: The things are called lanthanides and actinides. Shouldn't lanthanum and actinium continue to be used as the placeholders?

They're not placeholders. The * table and La table are different. Moreover, the whole point of the categories "lanthanide" and "actinide" is that those elements are similar to La and Ac. It seems quite weird to put La and Ac away from the rest of them. It is less weird for Lu (whose properties among the lanthanides are furthest from those of La) and not weird at all for Lr (which is quite unlike the other late actinides Es-No in properties).

Q9: IUPAC is the relevant source here, surely? What do they have to say?

They show their table as a * table, but they also state:


So it is not clear if that is an actual IUPAC recommendation for the * form or not.

IUPAC also organised a project to resolve precisely this issue, as can be seen from number 7 on their periodic table page. That project considers the La and Lu alternatives, but not the * one that they currently show. It started in 2015 and still has not concluded anything. Since it has both strong La and Lu proponents on it I also doubt it will conclude anything soon.

All we can conclude for now is that they seem to intend to deprecate the * form they currently show, thus leaving us without a firm guide in the meantime.

Q10: Why aren't we waiting for them then?

Because (1) I doubt that their work will be finished anytime soon, (2) we don't always follow IUPAC (we follow it for spelling aluminium but not for phosphane), and (3) any way you look at it, we have to show something in the meantime, see Q7.

I argue that we should look at the consensus of reliable sources that focus on the matter. Because an article focusing on group 3 and explaining why the authors think La or Lu should be there, I argue, outweighs in terms of reliability somebody who just draws a periodic table and gives no clue as to why he or she has drawn it that way. I claim that's in favour of Lu.

Questions 11 to 15

Q11: What do most reliable sources say?

Depends really. If you do a Google Image survey on "periodic table", * below Y dominates with proportions La:Lu:* of 1:1:4. The IUPAC project organised a survey that seems to show that La below Y dominates in textbooks (with La:Lu:* proportions of 4:1:1). However usually those textbooks have * in the same cell as La with a group 3 header above, therefore also implicitly claiming that the other lanthanides go there. So there is, at least, an ambiguity. Also, all these dominances are just 2/3 majorities, it's not a rare thing at all to find a textbook or periodic table poster giving Lu below Y.

I claim it's more relevant to look at what articles specifically focusing on this issue tell us, because it's common for textbooks to repeat standard errors on issues like this (e.g. claims that d orbitals are involved for phosphorus in PCl5, which are false but ubiquitous in textbooks), and most of these textbooks are hardly focusing on these heavy 4f and 5d elements that the dispute is all about. Those have a majority supporting the Lu form. I tallied them with Sandbh in an old submission to IUPAC we made on this matter in 2016; I've updated the list to 2020 below. Back then we agreed that La is better; then I changed my mind in response to new evidence from Droog Andrey that Lu is better, so we started arguing.

Advocates Lu Advocates La Advocates *
Bury (1921)
Shemyakin (1932)
Landau and Lifshitz (1958)
Hamilton (1965)
Merz and Ulmer (1967)
Chistyakov (1968)
Mathias (1971)
Wittig (1973)
Jensen (1982 and again 2015)
Holden (1985)
Fang et al. (2000)
Horovitz and Sârbu (2005)
Wulfsberg (2006)
Ouyang et al. (2008)
Scerri (2012)
Nelson (2013)
Settouti and Aouragi (2014)
Alvarez (2020) 		Smith (1927)
Trifonov (1970)
Shchukarev (1974)
Atkins (2006)
Lavelle (2008)
Restrepo (2017)
Cao et al. (2020) 		Xu and Pyykkö (2016)

Q12: Aren't you essentially claiming that a whole lot of eminent scientists are wrong?

It's a controversy. No matter which side you pick you're going to be claiming that a whole lot of eminent scientists are wrong. La advocates like Sandbh have Sergey Shchukarev on their side, Lu advocates like me have Landau and Lifshitz, so we can see that both options have had respected adherents. That's why I claim we have to look at the articles focusing on this issue and also consider the chemistry involved.

Q13: Many chemists have never heard that there was such a debate. Are you sure you're not just another fringe theory peddler?

Landau and Lifshitz are hardly "fringe". Neither is Clayden et al.'s Organic Chemistry, which has a Lu table. And Jensen, before his 1982 article, had not heard of this debate either.

Q14: What is the status of that interminable thread at Wikipedia talk:WikiProject Elements, stretching from last December to this July?

We have 5-1 for Lu and an extra two who at least think the La arguments proffered are problematic.

  • Well, I guess it goes without saying that I support the Lu form, yes?
  • "La arguments are totally local, while Lu arguments are pretty regular. That exactly matches Ptolemy vs. Copernicus. The history just repeats itself. Nothing more to say." - Droog Andrey
  • "Cool, thanks. This makes perfect sense. Well said. Team Lu for me!" - Dreigorich
  • "I'd really just want to get rid of the Scandium/Yttrium overhang in the long periodic table. It is ugly and very artificial IMO." - Officer781
  • "I am more convinced by the Lu arguments I've read, and given the support of the scientific community and lack of consensus against it here (no "battleship" as you describe), I'll join the RfC once it's underway." - ComplexRational
  • "Even worse, a publication may be biased towards a preference for more simple or elegant or 'by authority' (IUPAC) form, which is a beauty contest not science. I understand Sandbh does argue for such criteria seriously, but that still does not convince me—FWIW." - DePiep
  • "I have noted in the very beginning of this discussion, which started with an article you [Sandbh] wrote, that it did not appear to me that pro-La-Ac and pro-Lu-Lr arguments were given the same weight, and I said, perhaps not as explicitly but to the same meaning, that it looked like this was done so deliberately so that one option is favored over the other. I am afraid that what I've read so far reinforces this thinking within me." - R8R

versus a single one:

  • "Ahead of the recommendation of the IUPAC project I see no case for change." - Sandbh

However since we carried out the last change in an RFC, I feel (after discussion with R8R) that a proposed reversal should also go through an RFC. It seems only fair.

Q15: Have you addressed Sandbh's arguments there?

Yes, I responded to everything new he raised. Though not always in the most polite way after a few months of arguing, for which I am sorry.

Questions 16 to 20

Q16: Exactly why were you arguing this fiercely with Sandbh?

Well, he was writing an article, to be published in Foundations of Chemistry, that supports La under Y, and brought it to WT:ELEM for peer review last December. I and Droog Andrey disagreed with his arguments on what seemed to me to be logical grounds. Eventually it got to this:


I found this quite surprising and responded in a rather too harsh manner, which I'm sorry for. Nevertheless I still cannot agree with this approach. Unless we use logic as a base, I don't see how we can judge the strength of arguments.

Q17: So why did it last so long?

Arguing with him was very helpful to sharpen my own understanding. But let's be honest: "someone is wrong on the Internet" also had something to do with it on my part, and I should really wean myself off of that.

Q18: But you've not been a complete angel yourself dealing with him.

That is true. I'm sorry. I will undertake to be more civil in future.

Q19: What's the history of this neverending argument anyway?

Mendeleev more or less gave up on placing the lanthanides, mostly leaving it to his Czech colleague Bohuslav Brauner. After some other attempts, eventually a form with all lanthanides under yttrium (basically the * form) was settled on. However even during this time tables that quite clearly don't put La under Y had already appeared (Henry Bassett 1892, Alfred Werner 1905). Actually Werner's form (yes, that's the father of coordination chemistry we're talking about) is incredibly close to the modern 32-column Lu form (with the exception that Be and Mg go over Zn instead of Ca). The only reason I do not call it a Lu table is because Lu had not yet been discovered(!).

In the 1920s and 1930s some chemists assigned Lu under Y because the chemistry of Y is more similar to Lu than La (Sc, Y, and Lu separate in the yttrium group of rare earths, but La and Ac in the cerium group).

The current dominance of the La form seems to stem, according to Jensen, from wrong electron configurations from the 1940s in which the lanthanides were assumed to be fn-1ds2 instead of fns2. These were later corrected, but by that time it seems the La form had stuck. We should not forget that these electron configurations are for the gas-phase ground state and are not really relevant for chemistry anyway (in chemical environments they change).

Meanwhile articles supporting Lu have appeared since 1921 and have been going on until the present; there have not been as many articles supporting La. Some authors have changed their periodic tables, others have not, there is still no consensus. IUPAC started a project in 2015 to look into it, they still have not made a decision.

It is possible that things will change. Be-Mg-Zn was present in Werner's periodic table of 1905, B-Al-Sc was once shown by Pauling(!), and prior to Seaborg it was generally accepted that the actinides known (Ac, Th, Pa, U) form a fourth d block row with uranium being eka-tungsten. Now you don't see any of these.

Q20: Should tradition count for something here?

There's not much of a tradition when chemists still argue about it. I prefer that we take the option that most of them who really analyse the issue support when we're not discussing the issue.

Questions 21 to 25

Q21: Would it not simply work if we just added footnotes like for helium where we explain that the other option is also common?

For the infobox, for the footer, you do not want to emphasise the issue where it is irrelevant, e.g. for the article on helium where group 3 matters not at all. The "overhang" the La table has in the 32 column form draws the eye's attention. The "stretchy scandium and yttrium" of the * table draws even more of the eye's attention. In order to make them look good, you have to use an 18 column instead of a 32 column form, which strikes me as not terribly good considering that those are supposed to be the same thing (just with the footnote glued in or not). So for these purposes I claim the Lu table is better: it preserves the symmetry. Moreover there is even scientific basis for preserving that symmetry, as the periodic table is explained by the valence orbitals and thus quantum mechanics, the Madelung rule having derived in the 1950s by Klechkovsky already.

Of course, whenever it is relevant (i.e. article of lanthanum, article of lutetium, and the period 7 congeners), we will add a note like there is for helium (about helium over beryllium being supported by some chemists). That goes without saying, for WP:NPOV reasons. But I think the reader would be better served with a Lu under Y default for when the situation does not matter.

Q22: OK, so are you going to get on to the scientific basis of this change or not?

Here are eight short arguments and the evidence behind them.

Melting points of the group 1 through 4 metals
  1. Per Jensen (1982) Lu under Y matches the trends in the d block better.
  2. Per Gschneidner (2016) La has 4f involvement in the metal that impacts its melting point, making it 450 °C lower than expected. The figure to the right from his paper shows "pseudo-La" for the expected melting point of La if it didn't have this 4f hybridisation. Such 4f involvement also ties together lots of properties of lanthanum: it explains melting point, heat of sublimation, high coordination numbers around 12 (difficult to explain without f orbitals), cubic molecular geometries of lanthanum complexes (difficult to explain without f orbitals giving the symmetry), superconductivity (it is superconductive, but Sc, Y, Lu are not), quite possibly also its crystal structure (which matches the early f elements but is different from Sc, Y, and Lu). Putting La under Y misses the point that the first element for which the 4f orbitals are non-hydrogenic and can participate chemically is lanthanum, not cerium.
  3. Lutetium has no involvement of the f electrons in chemistry. All they do is contribute incomplete shielding effects which is exactly like the effect of the lanthanide contraction on hafnium through mercury. On those grounds it is surely a d element.
  4. Properties of yttrium are closer to those of lutetium than lanthanum.
  5. The only precedent for taking an element out of its block is helium, which is obviously much closer in properties to neon than beryllium. Why do that for lanthanum when yttrium is already closer to lutetium in all ways?
  6. Taking La out of the f block on the grounds of its ground-state gas-phase electron configuration lacking a 4f electron is irrelevant (these configurations change in chemical environments) and inconsistent with thorium. Thorium is in the f block, yet its ground-state gas-phase configuration lacks a 5f electron. Besides the periodic table is not even based on ground-state gas-phase electron configurations in the first place, as evidenced by the fact that no one rips nickel [Ar]3d84s2, palladium [Kr]4d105s0, and platinum [Xe]4f145d96s1 apart from each other. Rather it is based on the number of valence electrons and which orbitals they may enter across all chemical environments.
  7. Examining properties reveals that La fits well with f elements, but is an outlier in the d elements. Same is true for Ac. Lu is OK either way (mostly), but Lr seems to fit well in the d elements but is an outlier in the f elements (we mostly only have predictions for that one of course).
  8. When examining properties, Eu and Yb show the properties expected and known from Mn and Zn (half-filled and filled subshell); Gd and Lu do not. That supports La-Yb as the f block. In fact a lot of analogies with the d block strongly support La-Yb as the f block for exactly this reason (standard electrode potentials, electronegativity, ionisation energies, melting and boiling points).

Everything said of the lanthanides above is also true or suspected of the corresponding actinides.

Evidence

For the 7th period elements no one has ever made more than a few atoms of, calculated properties have been used.

Jensen (1982), Table 1

In general properties of Sc-Y-Lu match the d block trend better. Sc-Y-La matches the s block trend, but remember that group 3 is a d block group, and the s block groups are in fact anomalous: they break the trend of having no even-odd periodicity. (Even-period elements usually are more electronegative and more oxidising in higher oxidation states; odd-period elements act the opposite way. From 5d onwards relativistic effects make it not quite right, as 5d is electronegative but prefers higher oxidation states, and 7p is electropositive but prefers lower oxidation states. But mostly it is still correct as a generalisation.) That's because there's no contraction: 

1s            period I
2s       2p   period II
3s       3p   period III
4s    3d 4p   period IV
5s    4d 5p   period V
6s 4f 5d 6p   period VI
7s 5f 6d 7p   period VII

From the build-up of the periodic table we see that for non-s blocks, even periods either have the first orbital of a given angular momentum (which is smaller than expected), or they have suffered a new contraction that wipes out the expected increase of radius and basicity (3p-4p increase wiped out by 3d, 4d-5d increase wiped out by 4f, 5p-6p increase wiped out both by 4f, 5d, and relativistic contraction of 6s). The s block is an exception: it always sits right above the noble gas core and never has any incomplete shielding effects (except a tiny bit for 2s vs 3s, and the obvious massive exception of 1s). There's no reason why any other group should follow them.

1st ionisation energies of the elements. Lu and especially Lr fall off the trends of the lanthanides and actinides respectively, and fit better with the trends of the succeeding 5d and 6d transition metals.

3rd ionisation energies of the transition elements (makes sense, having ionised the s electrons away already, and now probing the energies to remove a d or an f electron). This is not perfect, but when the configuration is "wrong", the "right" one is usually so close that it doesn't matter. La2+ is [Xe]5d1, but the expected [Xe]4f1 is about 0.89 eV up in energy; Gd2+ is [Xe]4f75d1, but the expected [Xe]4f8 is about 0.30 eV up in energy. I hope we agree that this is small potatoes compared to the differences between neighbouring elements.

Natural families La-Eu and Gd-Yb are supported, following Sc-Mn and Fe-Zn; the half-full and full subshell gives a local maximum in energy, because the next electron going in is either paired (after half-full) or in a higher-energy subshell (after full) and is then easier to remove. The effect weakens for higher rows (as you can see from the 1st IE chart as well; N-O is an obvious blip downward, P-S is not so obvious, by Sb-Te it doesn't go down anymore), but you can still see it.

property La Lu Hf Ta W Re Os Ir Pt Au Hg
m.p. (K) 1193 1925 2506 3290 3695 3459 3306 2719 2041.4 1337.33 234.43
b.p. (K) 3737 3675 4876 5731 5828 5869 5285 4701 4098 3129 629.88
specific heat capacity (J/(g*K)) .195 .154 .144 .14 .132 .137 .13 .131 .133 .129 .14
EN (Pauling) 1.1 1.27 1.3 1.5 2.36 1.9 2.2 2.2 2.28 2.54 2.0
EN (Kulsha-Kolevich) 1.11 1.31 1.38 1.46 1.54 1.55 1.67 1.75 1.84 1.93 1.81
Density 6.145 9.84 13.31 16.654 19.25 21.02 22.61 22.56 21.46 19.282 13.5336
Young's modulus 36.6 68.6 78 186 411 463 ??? 528 168 78 ???
Bulk modulus 27.9 47.6 110 200 310 370 462 320 230 180 25
Resistivity (nΩm, close to r.t.) 615 582 331 131 52.8 193 81 47.1 105 22.14 960
Brinell hardness (MPa) 350-400 893-1300 1450-2100 441-3430 2000-4000 1320-2500 3920-4000 1670 310-500 188-245 ???
Heat of fusion (kJ/mol) 6.20 22 27.2 36.57 52.31 60.43 57.85 41.12 22.17 12.55 2.29

In most properties Lu matches the properties of the 5d elements better than La. That is also true for chemical properties (Lu is less basic and less big as a cation, matching 5d elements better), but those are harder to show as data. ^_^

property Ac Lr Rf Db Sg Bh Hs Mt Ds Rg Cn
m.p. (K) 1323 1900 2400 ??? ??? ??? ??? ??? ??? ??? 283
EN (Kulsha-Kolevich) 0.97 1.29 1.34 1.41 1.49 1.59 1.72 1.83 1.92 1.99 1.91
Density (g/cm3) 10.07 15.6 23.2 29.3 35.0 37.1 40.7 37.4 34.8 28.7 14.0
1st IE (kJ/mol) 499 470 580 665 757 740 730 800 960 1020 1155
3rd IE (kJ/mol) 1900 2228 2300 2378 2484 2570 2830 2900 3030 3080 3160

The little known and predicted about Ac vs Lr-Cn seems to show the effect is even stronger. All bulk properties of Lr-Cn are of course predictions as nobody has ever made enough. Kulsha-Kolevich electronegativity was used because no other scale actually seems to have values for elements as heavy as copernicium.

property Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
1st IE (kJ/mol) 499 587 568 598 605 585 578 581 601 608 619 627 635 642 470
3rd IE (kJ/mol) 1900 1978 1814 1900 1997 2084 2132 2026 2152 2267 2334 2363 2470 2643 2228
m.p. (K) 1323 2115 1841 1405 917 913 1449 1613 1259 1173 1133 1125 1100 1100 1900
EN (Kulsha-Kolevich) 0.97 1.01 1.04 1.06 1.08 1.12 1.07 1.18 1.22 1.27 1.32 1.36 1.39 1.37 1.29
Density (g/cm3) 10.07 11.72 15.37 18.95 20.45 19.84 13.69 13.51 14.79 15.1 8.84 9.7 10.3 9.9 15.6

Lawrencium's properties, as far as they are predicted, seem to be a quite bad match for the late actinides. (Data for Fm through Lr bulk properties is predicted, no one has ever made enough.)

M Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge
mp (°C) 842 1541 1668 1910 1907 1246 1538 1495 1455 1085 420 30 938
bp (°C) 1484 2836 3287 3407 2482 2061 2861 2927 2730 2562 907 2400 2833
M Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf
mp (°C) 727 920 795 935 1024 1042 1072 826 1312 1356 1407 1461 1529 1545 824 1652 2233
bp (°C) 1633 3464 3443 3130 3074 3000 1900 1529 3000 3123 2567 2600 2868 1950 1430 3402 4603

Double periodicity in melting and boiling points likewise supports La-Eu and Gd-Yb as natural f-block subfamilies. (When we get to a half-filled or filled subshell, delocalisation of those electrons becomes less favourable.) The effect is weaker for succeeding rows as usual.

M Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga
M3+/M2+ potential very high −2.3 −0.9 −0.255 −0.42 +1.56 +0.771 +1.92 +2.3 +2.4 very high −0.8
M Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In
M3+/M2+ potential very high −2.8 ??? −0.9 −0.2 +0.3 +0.24 +0.7 ??? +1.8 very high −0.49
M Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
M3+/M2+ potential very high −3.1 −3.2 −3.1 −2.7 −2.6 −1.55 −0.35 −3.9 −3.7 −2.6 −2.8 −3.0 −2.2 −1.05 −2.7
M Ra Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
M3+/M2+ potential very high −4.9 −4.9 −5.0 −4.7 −4.7 −3.5 −2.3 −3.7 −2.8 −1.6 −1.3 −1.1 −0.1 +1.4 −2.6

The standard reduction potential trends across the two subfamilies La-Eu and Gd-Yb are smooth, like those of Sc-Mn and Fe-Zn; they reach maxima at the half-filled and filled subshell elements as expected as then it is more difficult to ionise an extra electron past the half-filled or filled subshell. Same goes for 3rd ionisation energies, and same goes for melting and boiling points (more difficult to delocalise those electrons).

We use +2 oxidation states as a baseline to compare like with like: this way the s electrons are ionised, the configurations involved are (almost always!) dn and fn, when they are not the difference in energy to that is usually small enough to ignore, and we can probe the stabilising effect of the real half-filled and filled shell. Of course you may artificially shift to the +3 state and get different results, but it has about as much meaning as plotting 2nd ionisation energies to "prove" that the periods should go from group 2 to group 1:

element He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca
2nd IE (kJ/mol) 5250.5 7298.1 1757.1 2427.1 2352.6 2856 3388.3 3374.2 3952.3 4562 1450.7 1816.7 1577.1 1907 2252 2298 2665.8 3052 1145.4

I hope we can agree that this is self-evidently absurd.

Conclusion

For these reasons I claim that the La form has no scientifically sound basis. It is not a good chemist's periodic table because yttrium is closer to lutetium than lanthanum, and because lutetium and lawrencium are far more like transition metals than lanthanum and actinium. It is not a good physicist's periodic table, because it goes away from the blocks that underlie the periodic table. And clearly teaching the Madelung rule is going to be pedagogically better than teaching the Madelung rule and then giving an exception for La that doesn't even match reality, given its 4f involvement.

This matches the criteria for putting elements in the periodic table as stated by Jensen, particularly arguments 2 and 3 (4f in La and its complete lack in Lu).


Q23: Are there any other La arguments that you haven't refuted above?

Differentiating electrons

Sandbh seems to believe in the importance of the "differentiating electron" of an element, which is the electron that differentiates it in its ground-state gas-phase configuration for the previous element. For example, since titanium is [Ar]3d24s2 (ground-state gas-phase), and vanadium is [Ar]3d34s2 (same), vanadium has a 3d differentiating electron.

I do not see why this should be important, given that we are not generally in the business of building elements up by adding one proton and one electron from the previous one. Also differentiating electrons are for the gas phase, and we've already discussed above that this is not relevant for chemistry because atoms usually have a different configuration when chemically bound from what they have sitting alone by themselves. Neither is it that clear all the time what exactly the differentiating electron ought to be. Passing from vanadium [Ar]3d34s2 to chromium [Ar]3d54s1 we have added two 3d electrons and subtracted one 4s one.

But all right, suppose we grant that. A usual argument Sandbh gives for why this should supposedly be important is looking at silver. It has a 5s differentiating electron as opposed to the 5d one of its heavier homologue gold, and this supposedly explains why the chemistry of silver is more main-group-like than gold:


On the other hand, technetium also has a 5s differentiating electron as opposed to the 5d one of its heavier homologue rhenium. Judging by how happy technetium is to interconvert between its many oxidation states like the transition metal it really is, this does not seem to do anything at all to make it more main-group-like at all.

Group divides

If you look at KCl, CaCl2, ScCl3, and TiCl4, the first three are ionic solids and the last one is a volatile liquid. So group 3 has to be cleft from group 4.

I used to believe this, but it doesn't really work. We may equally well observe the melting points of Cs2O, BaO, La2O3 or Lu2O3, HfO2, Ta2O5, WO3, Re2O7, OsO4. These are all high melting-point compounds until WO3, and the melting points keep increasing (showing ionic character) until HfO2. And we can multiply other counterexamples like Na2O, MgO, Al2O3, SiO2 (melting points increase till MgO).

Any way you look at it, this doesn't support any natural group divide at all. Mostly because there is no such thing outside the fundamental one (noble gas | alkali metal).

A related argument states that group 3 is more similar to group 2 than group 4 because group 3 acts like a trivalent version of the main group metals. But for group 4 you can find aqueous cations with noble gas configurations that make them like a tetravalent version. Simply make the pH low enough. −1 will do, you'll easily find things like Zr4+ and Hf4+, maybe even Ti4+, then. Well, look at Fajans' rules again. Cation polarising power, hence acidity, depends on charge and radius. Following Gary Wulfsberg's Principles of Descriptive Inorganic Chemistry, the usual dependence is on charge squared divided by ionic radius. We can then draw his table:

Z2/r ratio Pauling EN Category pKa Examples
0.00–0.01 <1.8 Nonacidic cations 14–15 Most +1 ions in s block
0.01 >1.8 Feebly acidic cations 11.5–14 Tl+
0.01–0.04 <1.8 Feebly acidic cations 11.5–14 Most +2 ions in s, f blocks
0.01–0.04 >1.8 Weakly acidic cations 6–11.5 Most +2 ions in d block
0.04–0.10 <1.8 Weakly acidic cations 6–11.5 All +3 ions in f block
0.04–0.10 >1.8 Moderately acidic cations 1–6 Most +3 ions in d block
0.10–0.16 <1.8 Moderately acidic cations 1–6 Most +4 ions in f block
0.10–0.16 >1.8 Strongly acidic cations (−4)–1 Most +4 ions in d block
0.16–0.22 <1.8 Strongly acidic cations (−4)–1
>0.16 >1.8 Very strongly acidic cations <−4
>0.22 <1.8 Very strongly acidic cations <−4

And indeed, we find that while the group 4 cations are indeed strongly acidic, they are not so acidic that they react irreversibly with water: the pKa is not quite low enough. Sure, you'll soon get a precipitate if their cations are introduced to aqueous solution at all but pretty low pH. But you can redissolve that precipitate in concentrated hydrochloric acid, at least if it hasn't aged too much. It's cations like Nb5+ and Ta5+ that are "very strongly acidic": too acidic to exist in water at all. So, apparently the group divide is really between groups 4 and 5 instead.

But probably the clearest way to rebut this whole idea is to look at what happens in the p block. Group 13 metals Ga, In, Tl can form aqueous cations in their group oxidation state. Group 14 metals Ge, Sn, Pb cannot, they are too acidic. (Remember what I said before? Elements in higher oxidation states are more electronegative and hence more acidic, whence how Pd2+ is more acidic than Be2+.) So this seems to also support B-Al-Sc if you apply it consistently. I think that is not a good sign.

The chemistry of group 3 is not more similar to that of group 2 to group 4, so that justification is also out. Observe the aqueous chemistry of group 4 and the organometallic chemistry of group 3. Not to mention that the standard "transition metal" property everyone knows from high school is forming coloured paramagnetic compounds with incomplete d orbitals. If you think scandium should be disqualified, because you will have a tough time finding stable lower-oxidation state compounds of Zr-Hf-Rf in group 4 and Nb-Ta-Db in group 5, those suddenly are also in danger of being disqualified. And as for the other s-block property of forming hard, class-A cations – the elements up to group 6 show that. Everything is a continuum here, and transition properties are no exception: they go in slowly, they come out slowly. All peripheral groups in blocks have properties similar to their block neighbours, there's no reason why to emphasise the property this much for group 3.

Ions

According to this argument, lanthanum cannot start the f block because La3+ fails to have an f electron, and there is complete regularity down Ce3+ to Lu3+ in showing f1 to f14. But such a common stable oxidation state for everybody only exists in the f block, and actually only the 4f elements, not the 5f ones. So this argument is about as local as you can get and doesn't work as part of the periodic law.

I also note that by this logic La cannot be in the d block either, since La3+ is d0. In fact it cannot be anywhere in the periodic table either, since La3+ is also s0 and p0. And there are no s block elements either except helium (the least s-block-like of them), because in their common oxidation states (+1 for the column H-Li-Na-K-Rb-Cs-Fr, +2 for Be-Mg-Ca-Sr-Ba-Ra) they are all s0. Why should we use criteria that only apply to one block?

Finally, La had been [Xe]4f16s2, all this argument would surely never have started: a La-Yb f block (i.e. a Lu table) would be absolutely standard. But it would still lose the f electron in the +3 state anyway, so this argument would still argue for Ce-Lu anyway. That seems hard to accept.

A Pair Out of Place

According to this argument, advanced by Lavelle, La and Ac cannot be put in the f block because they would represent the only case of two elements going into a block with no outer electrons in common with their block.

Of course, this is predicated on the gas-phase ground-state configurations, which is not that relevant. Also, how does this deal with Lu and Lr? Neither of them have any outer f electrons, they also form a pair out of place. So the argument is as much for the Lu table as it is for the La table.

Q24: Weren't you on the other side of this last time?

Indeed. I learnt more, I changed my mind. All thanks to Droog Andrey (= A. V. Kulsha). You may enjoy the periodic table poster he and one of his colleagues created too (link is to version of 2019). ^_^

Q25: So what's wrong with the old arguments that you were using then?

I've addressed them all above.

Questions 26 to 30

Q26: So how do I know you won't be fervently arguing to change it back again in four years?

I don't, that's because I believe in the scientific method. If I find out something falsifying my stand, I change my mind. You can argue it if you want... ;)

Q27: Why now? Why not wait for IUPAC?

It's not possible to be neutral. Sc-Y-* is also a side. I also think Sc-Y-* is chemically just weird (those f electrons are not core electrons, and while asking La-Lu to share one flat makes some sense, it's really weird for Ac-Lr), and Jensen agrees.

Q28: Why start it now and not earlier?

Because my ideas about this were not clear enough till this round of argument with Sandbh started. Now they are.

Q29: Do you have nothing better to do than write long screeds here about this?

Well, at R8R's suggestion it is now behind a collapse box, and most of the long screeds have been replaced by very short answers.

Q30: Do you have anything against Sandbh personally?

No, I just find myself in disagreement with his stand on logic and falsifiability.

Mass summoning

@ComplexRational, DePiep, Droog Andrey, Officer781, R8R, Sandbh, Дрейгорич, AzaToth, Tazerdadog, Maproom, CuriousMind01, Silvio1973, and Timtempleton: Pinging all megathread and previous RFC participants. And also AnthonyDu0122 who raised it above. ^_^

Unacceptable behaviour

​​​​​​​​​​​​​​I object, in the strongest possible terms, to the way Double sharp initiated this RFC.

I allege that Double sharp's background to the RFC is biased; incomplete; out-of-context; contains inappropriate content; and—at 33,000 words—is too long for anyone to gain an informed understanding of the issue at hand. This follows other unacceptable behaviour alluded to on his part, including his hack work on our periodic table article; removing some of my citation supported content; slandering me; swearing; and effectively demanding I provide a falsifiable hypothesis when I was under no obligation to do so.

The context for my objection is my long-term participation in the Group 3 debate, including two submissions to IUPAC on the matter, one with Double sharp (which he has now dissociated himself from).

My other objection is that an article written by me will soon appear in the journal Foundations of Chemistry, entitled "The location and composition of Group 3 of the periodic table". I have the proofs in hand. The article has been reviewed by three PhDs and accepted for publication by Eric Scerri, a world authority of the periodic table. Scerri is also the chair of the IUPAC Group 3 project.

Double sharp knows all this, yet chooses to go ahead with the RFC. So much for taking into account "reliable sources that focus on the matter." So much for extending me the courtesy of professional respect. So much for working collegiately within WP:ELEMENTS.

Here again is a continuation of his pattern of unacceptable behaviour.

Most of the rest of the editors who have voiced their opinions for Lu, it seems to me, do so on the basis of a personal preference or a very limited grasp of the full extent of the arguments and literature involved in this case.

I'm not holier than anyone. I do claim, along with Double sharp, to have maintained a depth of familiarity and interest in this question since at least 2016. In my case I've been arguing the question with Scerri, on and off, since 2008. And along the way, Double sharp and I have changed our minds about Group 3 as we both learnt new things along the way.

As Jones (2010) has written:

"Scientists should not lose sleep over the hard cases. As long as a classification system is beneficial to economy of description, to structuring knowledge and to our understanding, and hard cases constitute a small minority, then keep it. If the system becomes less than useful, then scrap it and replace it with a system based on different shared characteristics."
Jones 2010, Pluto: Sentinel of the outer solar system, Oxford University Press, p. 171

As Schwerdtfeger, Smits & Pyykkö (2020) wrote:

"Fuzzy concepts like chemical similarity often lead to unnecessary disputes concerning the PTE."
Schwerdtfeger P, Smits OR & Pyykkö P, 2020, "The periodic table and the physics that drives it". Nature Reviews Chemistry, vol. 4, pp. 359–380

That is why we have an IUPAC Group 3 project team, to assess the literature and address these unnecessary disputes.

And the IUPAC project team has reported that, based on a survey of chemistry textbooks and other sources, that the La form dominates by a 4:1:1 margin, where the two 1's are the *-** form and the Lu form.

As Scerri wrote:

"…the majority of textbook and other periodic tables in the 18-column format show the elements of this group as scandium, yttrium, lanthanum and actinium…"

Scerri ER 2020, "Recent attempts to change the periodic table", Philosophical Transactions A, here

As WP:Elements member R8R wrote:

"…I'll say that the 4:1:1 consideration will be very important for the upcoming RfC, especially given that it's something that can be found on IUPAC's official website. I agree that consistency with literature is of the uttermost importance for Wikipedia if literature itself goes shows such a consistency; Wikipedia is meant to be a tertiary source. It'll be the thing that will hold me from supporting the motion on WP right now…--R8R (talk) 16:51, 19 July 2020 (UTC)"

Precisely.

The way ahead, as I see it, is (1) cancel the RFC until my article appears on line; and (2) Double sharp and I to agree on a balanced introduction to a new RFC, should Double sharp wish to proceed with another RFC. Failing this I will take up the matter on WP:AN. --- Sandbh (talk) 03:27, 21 July 2020 (UTC)

The supposed consistency of the literature has been addressed above by noting that most reliable sources focusing on the issue support Lu, and that the 4:1:1 for La:Lu:* is of questionable relevance due to (1) Google results showing instead 1:1:4 for periodic tables, (2) general ambiguity resulting from * appearing in the same cell as La, and the fact that (3) there are some things that have been demonstrated many times in reliable sources but tend not to be taken up by textbooks, e.g. the refutation of d orbital involvement for hypervalent molecules. Incidentally, in the article Sandbh links to, Scerri supports Lu under Y.
I have added a thread at WP:AN#Dispute on an RFC. Double sharp (talk) 04:17, 21 July 2020 (UTC)
To address Sandbh's concern about length, I have removed the long bottom-up explanation of periodicity, leaving only the arguments. Since we have been arguing about this for nearly seven months now at WT:ELEM, I think trying to create a balanced introduction to a new RFC that will please both of us may well be futile because our approaches diverge very early: many arguments that one of us consider decisive are not considered so by the other. However, I have absolutely no objection to him adding his own view of the background next to mine. Double sharp (talk) 04:58, 21 July 2020 (UTC)
On the "supposed" consistency of the literature

Here is what Double sharp neglects to mention.

Mathias (1969) grumbled about La in group 3 being the most popular form. Myers, Oldham and Tocci (2004, p. 130) found La and Ac to be the most popular form of periodic table, a sentiment echoed by Clarke and White (2008); and Lavelle (2008; 2009). My article (Vernon 2020) will reiterate this.

Clark RW & White GD 2008, "The flyleaf periodic table", Journal of Chemical Education, vol. 85, no. 4, p. 497
Lavelle L 2008, "Lanthanum (La) and actinium (Ac) should remain in the d-block", Journal of Chemical Education, vol. 85, no. 11, pp. 1482–1483, doi: 10.1021/ed085p1482
—— 2009, "Response to misapplying the periodic law", Journal of Chemical Education, vol. 86, no. 10, p. 1187, doi: 10.1021/ed086p1187
Mathias BT 1969, "Systematics of superconductivity", in PR Wallace (ed.), "Superconductivity: Proceedings of the Advanced Summer Study Institute on Superconductivity", McGill University, Montreal, vol. 1, Gordon and Breach, New York, pp. 225−294
Myers RT, Oldham KB & Tocci S 2004, Holt chemistry, Holt, Rinehart and Winston, Orlando
Vernon RE 2020, "The location and composition of Group 3 of the periodic table", Foundations of Chemistry, open access (in press)

As noted, IUPAC and Scerri have confirmed this. Double sharp knows it but neglects to mention it. There is no support in the literature for his WP:OR interpretation.

Scerri has noted (pers. comm.) that he distinguishes between his personal view as a chemist, and his role as the chair of the IUPAC Group 3 committee. Once again Double sharp demonstrates that he does not know what is going on here.

I reject Double sharp's assertion that it would not be possible for is to reach agreement on a balanced approach to an RFC. Once again he resorts to unwarranted—act of desperation—escalation i.e. 1. the hack work on our periodic table; 2, this RFC; 3. unilateral escalation to WP:AN. 08:05, 21 July 2020 (UTC)

Last try at being reasonable

@Double sharp: So, are we going to cancel this RFC and come up with an NPOV version, suitable for another RFC post online publication of my article, or are you going to waste everyone's time and some poor WP:ADMIN's? Sandbh (talk) 08:19, 21 July 2020 (UTC)

@Sandbh: RFC tag removed (I understand this withdraws the RFC).
Now I have stepped back and thought about it. I have gone overboard, and I apologise for it. I am still not at all convinced by your arguments and believe the Lu form is significantly better. However, since I also believe helium over beryllium is significantly better, yet recognise that that approach has no chance to become the default on WP, I am willing to let this one go provided we add notes to the relevant articles like what I did on helium explaining that there is a dispute. So, I have decided not to start a new RFC even after your article is published.
I do not wish to discuss the issue further on WP at present. Everything relevant has already been said far too many times, and it seems unlikely that either of us are going to change our minds if it is said more times. It is also true that the fact that most textbooks discuss Sc, Y, La, and Ac together is, for Wikipedia, probably definitive at this moment. So, let's drop the issue until and unless IUPAC decides eventually on Lu under Y. In that circumstance, I think no one will argue that an RFC will be justified, but we do not have it at the moment.
Respectfully, Double sharp (talk) 08:51, 21 July 2020 (UTC)

Discussion

  • Neutral on the change but Strong support that the periodic table article should show both forms and give some (brief!) discussion of why some reliable sources use La and others Lu. There is no such thing as the periodic table, it has been presented in numerous forms over the years and Wikipedia should reflect that. However there is only one periodic table article and we need to put a summary there reflecting WP:NPOV on the various forms. Michael D. Turnbull (talk) 11:37, 20 July 2020 (UTC)
Now Against the change after the useful clarification that we are really only talking about the appearance of Wikipedia templates like {{Periodic table}} (See top of this RFC thread). We should stick to the same version as IUPAC currently endorse, i.e. IUPAC (2018-12-01). "PERIODIC TABLE OF ELEMENTS". since that's what most readers would expect. (Even British chemists don't use sulphur now, only sulfur.) Michael D. Turnbull (talk) 13:49, 20 July 2020 (UTC)
Actually it is not quite true that IUPAC endorses the form. They write on their website "While IUPAC has no recommendation for a specific form of the periodic table, i.e. 18-column or 32-column format, the version here presented is in the conventional long form and is yours to use."
Now I can see the argument for using * under Y as that's what IUPAC shows on their webpage, even if they seem to be planning to change it away from * under Y eventually. But it does make things awkward for the 32-column forms encountered in {{Compact periodic table}} etc. Will scandium and yttrium have to be stretched over 15 columns? The only way it becomes less awkward is if we change those to the 18-column form too. Which is a bit odd as the 18 and 32 column forms are supposed to be saying the same thing in a different layout. Double sharp (talk) 13:56, 20 July 2020 (UTC)
  • Strong support on changing to Lu as per arguments above. I was involved in the discussion itself as a minor participant. ― Дрейгорич / Dreigorich Talk 12:29, 20 July 2020 (UTC)
  • Support change to Lu per arguments above; I also was a minor participant in the group 3 megathread. I would also like to comment that the IUPAC standard is intended to be deprecated (that is why this RfC does not consider Sc-Y-*-*;(not originally considered here but later added) it is possibly even more incorrect to place all 30 inner transition metals below Sc and Y, and it still doesn't address how to structure the 32-column table), and the remaining arguments strongly suggest that Lu is the better choice. ComplexRational (talk) 14:11, 20 July 2020 (UTC)
    • @ComplexRational: BTW, I just added Sc-Y-*-** as an option since Michael D. Turnbull is in favour of it. So now it is not accurate anymore that the RFC does not consider the option. It is however correct that I am against that option. ^_^ Double sharp (talk) 14:18, 20 July 2020 (UTC)
  • Extremely strong oppose (I have to make this prominent to balance and counteract the supports above) Just about all the arguments are irelevant and we should just use the traditional form with La and Ac under Y. If needed we can use the place holder * or **. Graeme Bartlett (talk) 07:52, 21 July 2020 (UTC)
  • Illegitimate RFC due to breaching Neutral point of view, Verifiability, No original research, and Lack of civility. Sandbh (talk) 08:15, 21 July 2020 (UTC)
    @Sandbh: RFC tag removed (I understand this withdraws the RFC).
    Now I have stepped back and thought about it. I have gone overboard, and I apologise for it. I am still not at all convinced by your arguments and believe the Lu form is significantly better. However, since I also believe helium over beryllium is significantly better, yet recognise that that approach has no chance to become the default on WP, I am willing to let this one go provided we add notes to the relevant articles like what I did on helium explaining that there is a dispute. So, I have decided not to start a new RFC even after your article is published.
    I do not wish to discuss the issue further on WP at present. Everything relevant has already been said far too many times, and it seems unlikely that either of us are going to change our minds if it is said more times. It is also true that the fact that most textbooks discuss Sc, Y, La, and Ac together is, for Wikipedia, probably definitive at this moment. So, let's drop the issue until and unless IUPAC decides eventually on Lu under Y. In that circumstance, I think no one will argue that an RFC will be justified, but we do not have it at the moment.
    Respectfully, Double sharp (talk) 08:51, 21 July 2020 (UTC)
The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Periodic Table of Elements Misnamed for 150 Years

The table is not periodic. The elements are. The correct name is the table of periodic elements. Chemistry is a precise science and it seems incredible that every chemist in the English speaking community has overlooked this for 150 years.

The Table of Periodic Elements should replace the improper but universal Periodic Table of The Elements.

This is my original finding based on the rule that an adjective modifies the immediately following noun, viz., table.

I am the source, John Jaeger, Irvine, California. — Preceding unsigned comment added by SpiderMBA (talk • contribs) 21:38, 9 September 2020 (UTC)

No. First, WP:ORIGINAL. Second, WP:COMMON. Third, a table of periodic elements is accurately described as periodic, by association. Jtrevor99 (talk) 20:35, 12 September 2020 (UTC)
What is "periodic elements"? -DePiep (talk) 21:13, 12 September 2020 (UTC)

That expression is rarely found in the literature. For a 1994 example: “Pure elements being electroplated are numerous. Fig. 4 shows in a Mendele'v table of periodic elements, those elements (bold) which can be electrodeposited from aqueous solutions.” doi:10.1080/00202967.1994.11871029

That said, the elements do not show periodicity or an approximate repetition of properties until they are ordered according to their atomic number. Once so ordered the sequence can be arranged into e.g. a table or a spiral or a pyramid, and so on. Since periodicity is not an intrinsic property of the elements such as e.g. density or ionisation energy or electron affinity, the convention is to associate the adjective (periodic) with the arrangement (table, circle, octagonal prism, whatever) rather than the elements, since it is the arrangement that crystallises periodicity, not the other way round. Sandbh (talk) 12:01, 13 September 2020 (UTC)

Yes, as I understand it. The table (arrangement) is periodic (or: has periodicity), not individual elements. -DePiep (talk) 12:05, 13 September 2020 (UTC)
If we say "table of periodic elements, it implies that there are some other sort of elements which could not be described as periodic. But if periodic properly describes any elements, it describes then all, so this is not a plausible way to describe the elements.
On the other hand, if we say "periodic table of elements" it implies that there are other sorts of tables that cannot properly be described as periodic. And there are! The elements can be listed alphabetically, or by abundance (Abundance of the chemical elements), or by year of discovery (Timeline of chemical element discoveries §§ Ancient discoveries​ and Modern discoveries. Even a linear presentation be atomic number without the rows and columns to show periods and groups can hardly be said to be periodic.
So it is entirely appropriate to call it the periodic table of elements. YBG (talk)`
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