Talk:Periodic table/Archive 10

This is an archive of past discussions about Periodic table. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page.

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Coming changes in visual presentation

The wiki PT is currently undergoing a great discussion about an update, both in colors and possibly in some categorization and structure issues. Everyone would be welcome to join the discussion on the issues related to the table to present itself, see here, and potentially the discussion focused on technical details of presentation, here.--R8R (talk) 22:51, 10 January 2016 (UTC)

Two separate topics are opened:

WT:ELEMENTS Metallicity categorization review (scientific side, category definitions)

WT:ELEMENTS Category Color Set review (presentation side, colors to be used)

-DePiep (talk) 11:16, 11 January 2016 (UTC)

Group 3 as (possibly borderline) transition metals

Can we make a case for this to rescue transition metal from its current problems, to get it behind the reasonable IUPAC definition (like Cotton and Wilkinson) of groups 3-11? Double sharp (talk) 03:59, 24 December 2015 (UTC)

On a quick look, the article seems to give a more or less balanced overview; what problems do you have in mind?--R8R (talk) 04:58, 24 December 2015 (UTC)

It keeps using the 4-11 definition as default, like in the first section ("eight groups") and its criticism of including group 3 (either Sc/Y/La/Ac or Sc/Y/Lu/Lr - I prefer the latter now) based on their behaviour as catalysts. All fine and well, but IUPAC demands you include group 3, so is there a way to refute the arguments against it? One of them is that the +3 state dominates their chemistry (um, yeah, but it's also true for Zr, Hf, Nb, and Ta with their group oxidation states, and lower states are shown at standard conditions - IIRC, CsScCl₃ is an example), and another is their behaviour as catalysts. Double sharp (talk) 14:53, 24 December 2015 (UTC)

P.S. If you ask me about the ion thing, BTW, I'm uncomfortable with it. If you look at Li, for example, its chemistry is utterly dominated by the Li⁺ ion where it gives up its only 2s electron to get the helium configuration of 1s². That does not make it a period 1 element because its ions have no electrons with n = 2. The electron that participates in reactions is a 2s electron! So for Sc, the fact that Sc³⁺ dominates its chemistry just means that its 3d electron has participated in its chemistry. It's not like Zn or Ga where nothing is going to let the d-electrons out. So if our idea of a transition element is one that uses electrons that are not from the outermost shell, then we have the 3-11 definition, where the f-block become inner transition elements as they give up their s-electrons and at least a single d- or f-electron.

So a reasonable definition might be that an element is a transition element iff it is in the d-block and has a chemically contributing inner shell (e.g. Sc turnings combusting to form the sesquioxide), and an element is an inner transition element iff it is in the f-block and has a chemically contributing inner shell (yes, I phrased it to take care of annoying cases like La, Gd, Ac, and Th, so that the d-electrons would count). This would mean that Lu is a lanthanide, but not an inner transition metal, but La is both (my excuse is that 4f is playing a role in La, whereas in Lu it is part of the core). There are thus 30 lanthanides and actinides (La-Lu, Ac-Lr) but only 28 inner transition elements (La-Yb, Ac-No).

All of this must be applied at standard conditions, of course, or we get absurdities like claiming K, Rb, and Cs to be transition metals.

The only trouble is that this bars Lr from TM status, because 7p is not an inner shell then. Troublesome! A possible way out is if the 6d configuration is a very low excited state: given the uncertainty in determining the correct configuration, this is probably the case. Then we do indeed have a chemically contributing 6d subshell that just happens to be empty in the ground state, like the case of 4f in La and 5f in Ac and Th.

The superheavy elements Cn, E113 (predicted), and Fl are PTMs until someone actually sees their 6d subshells breached. Until then, all we have are physical properties, which are in line with their groups and thus give a verdict of PTM.

Hence suggested colouring: same as now, but with Sc/Y/Lu/Lr as group 3, and with all of group 12 (Zn, Cd, Hg, and Cn) listed as PTMs. (Since we colour Ln/An and not ITM, and this is my OR definition after all, Lu and Lr are still coloured as a lanthanide and actinide respectively, but they would also be considered d-block elements.)

We would consider Lu and Lr to be the heavier members of group 3 by default, i.e. in all contexts except different ways to draw the periodic table. This is fine as all three versions are supported by numerous reliable sources, and we have to pick one. We might as well pick the best of them! ^_^

We also ought to do this sort of thing for the placement of H and He in another thread to determine our defaults. Although I suppose I can take the opportunity to say that because we are looking at standard conditions, putting He anywhere except over Ne is ludicrous for a default. Double sharp (talk) 15:19, 24 December 2015 (UTC)

P.S. I can't believe I forgot to define the blocks. Okay, here goes: an element is in the x-block (x = s, p, d, f, or g) if the outermost x-orbitals are (expected to be) chemically active in it. The precedence rules are: p, g, f, d, s. Hence La is in the f-block since 4f and 5d are both active and f precedes d. E113 is in the p-block since p beats everything: the same is true for C with both 2s and 2p. That covers the majority of cases, but falls down for group 12 as well as He and Ne. We presumably want group 12 in the d-block, as well as He in the s-block and Ne in the p-block; this puts group 12 in the s-block to get a bifurcating group 2 past Be, and there is no way to assign He and Ne to blocks until their nobility collapses. Double sharp (talk) 15:27, 24 December 2015 (UTC)

P.P.S. Oops. Lr. Actually it's not possible to create a precedence rule such that both Lr and E113 work because you need p to both be before d (for E113) and after d (for Lr). Obviously this is impossible, so here goes half my idea. I think my definitions of TM and ITM work, though. Double sharp (talk) 15:44, 24 December 2015 (UTC)

Scratch that: we are fine since 6d contributes to Lr's chemistry. Now only group 12, He, and Ne really create problems. Double sharp (talk) 21:18, 24 December 2015 (UTC)

Thanks for the Xmas gift. I'm slowly writing a response to your concerns about the transition metal article's focus on groups 4–11. There is more to this than what may be apparent. In the literature, the group 3 elements—and whether to treat them as d-block elements, transition metals or the other kind of transition metals—are the source of much categorical hand waving and contortion. Hope to post something soon. Sandbh (talk) 07:01, 5 January 2016 (UTC)

The group 4–11 focus

Abstract
In response to Double sharp's concerns, this post discusses the focus of the transition metal article on groups 4–11, and why this is not at odds with IUPAC or the literature. I conclude that colouring Sc and Y as transition metals is misguided since this is based on electron configurations rather than overall chemical, metallurgical and physical properties, and it Is the latter which informs how we colour categorise each element. (I count myself as having been misguided on this point until I thought at length about the issues raised by Double sharp.) I contend that Sc, Y and the lanthanides would be more relevantly colour coded as either "rare earths", "rare earth metals", "rare earths (lanthanides 57–71)" or "rare earth metals (lanthanides 57–71)".

Our transition metal article
I think the article uses the 4–11 definition because (a) Wikipedia categorizes only half of group 3 as transition metals; and (b) IUPAC says that group 12 elements are not always counted as transition metals. In these two senses the 4–11 definition is safe. The other sentence that uses the 4–11 definition is the second one in the Classification section, the one that says: "The elements of groups 4–11 are now generally [italics added] recognized as transition metals, justified by their typical chemistry, ie large range of complex ions in various oxidation states, coloured complexes and catalytic properties either as the element or as ions (or both)." Given the "generally" qualifier, this is a reasonably accurate statement.

A group 4–11 focus is not necessarily at odds with IUPAC as they are only definitive on d-block elements. The Red Book (2005 p. 51) says: "The elements of groups 3–12 are the d-block elements." That's definitive. And then it goes on to say, "These elements are also commonly referred to as the transition elements, though the elements of group 12 are not always included…". That's not definitive.† The d-block elements certainly are commonly referred to as transition elements but as well as group 12 not always being included, neither are group 3 or group 11 always counted as transition metals.

† IUPAC had earlier (in 1990) defined a transition element as "An element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell" i.e. groups 3–11. This guidance was superseded by the 2005 recommendation although it still appears in IUPAC's online Compendium of Chemical Terminology (The Gold Book).

Group 3 in the literature
The literature has a hard time dealing with group 3 as transition metals. More often than not authors have to either [1] mention that the group 3 elements don't characteristically behave like transition metals; or [2] treat them in the same vein as the lanthanides; or [3] deny they are transition metals in the first place.

Earnshaw and Harrington (1973, p. 52), say that it is group 4, rather than group 3, "in which the really characteristic transitional properties of variable oxidation state, color and paramagnetism are encountered."

Gschneidner (1975, p. 76) says of scandium that it…

"…is the lightest of the rare earth group of elements and is the first transition metal in the periodic table [i.e. in the electronic sense]…In its general chemical, metallurgical and physical behaviours it is similar to those observed for other rare earth metals, but there are a number of significant differences. These are in part due to its smaller size (5.4% smaller than the next larger rare earth, lutetium) and its larger electronegativity value (1.28 compared to 1.12–1.22, for the other trivalent rare earths)."

There is nothing particularly surprising about the fact that scandium exhibits some differences when compared to its heavier congeners. This is a reflection of what Jensen (1986, p. 506) describes as…

"…a systematic variation in the periodic table which shows that the elements in the first row of any new electronic block tend to show abnormalities relative to the elements in later rows of the same block, and that the degree of divergence decreases in the order s-block>> p-block > d-block > f-block…C–F are quite distinct compared to other p-block elements, and the same is true to a lesser degree for Sc–Zn relative to the heavier d-block elements."

Neither scandium nor yttrium meet the profile given by F. A. Cotton (2000, p. 1961):

"The chemistry of the transition elements is differentiated from that of the other (so-called main group) elements in several ways, of which the following three are perhaps most important.

(1) The transition elements typically form compounds in two or more oxidation states, and redox chemistry, including electrochemistry, is of major importance.

(2) The majority of transition element compounds have visible spectra (which are why they are colored) and the interpretation of these spectra provides a wealth of information concerning their electronic structures. A classic example is provided by the spectra of tetrahedral and octahedral complexes of cobalt(II), as shown in Fig. 2.

(3) A great many transition element compounds have one or more unpaired electrons and therefore have interesting and often useful magnetic properties. These magnetic properties range from simple Curie paramagnetism to those associated with high-temperature superconductivity."

Greenwood and Earnshaw (2002, p. 946), refer to the group 3 elements (Sc, Y, La, Ac) as having properties that might be expected for elements immediately following the strongly electropositive alkaline-earth metals and preceding the transition elements proper [italics added]". That is, they don't regard the group 3 elements as "proper" transition metals. A little earlier (p. 958) they say that, "whatever arguments may be advanced against the description to Sc, there is no doubt that Ti is a "transition metal".

In their methodical survey of structure-property relations in nonferrous metals, Russell and Lee (2005) proceed from left to right across groups 1–2 and 4–16 of the periodic table. They skip the group 3 metals as these are included with the lanthanides.

Simon Cotton, a noted author on lanthanide chemistry, has a few words to say about scandium as a supposed transition metal:

(1) "The first 3d metal, scandium is not a transition metal, but has significantly different properties, partly on account of its slightly greater size, forming complexes with higher coordination numbers (e.g. the aqua ion [Sc(H₂O)₇]³⁺). Its developing chemistry is that of a slightly smaller version of lutetium." (2011)

(2) With a colleague, he again criticizes its treatment as a transition metal: "More still needs to be known about scandium chemistry; it is still too often regarded as a 3d transition metal even though it is now clear that it is quite unlike 3+ [sic] transition metal species." (Cotton & Harrowfield 2012).

(3) He observes that the Group 3 elements are "frequently" treated together with the lanthanides (2006, p. 107).

Rayner-Canham and Overton (2006, p. 484–485) write that, "Although some people use the terms d-block elements and transition metals interchangeably, this is not strictly correct. Inorganic chemists generally restrict the term transition metal to an element that has at least one simple ion with an incomplete outer set of d electrons." According to these authors, the elements commonly considered as transition metals are found in groups 4–11. They discuss the group 3 elements and lanthanides together in another chapter, given resemblances in the chemistry of the two sets of elements.

In the case of our nearest "competitor", The Encylopædia Britannica Online, their entry for transition metals (F. A. Cotton 2014) says:

"Because scandium, yttrium, and lanthanum actually do not form compounds analogous to those of the other transition elements and because their chemistry is quite homologous to that of the lanthanoids, they are excluded from the present discussion of the main transition elements. Similarly, because zinc, cadmium, and mercury exhibit few of the properties characteristic of the other transition elements, they are treated separately (see zinc group element)."

Britannica's own 18-column colour-coded periodic table (2010) categorizes the group 3 metals as rare earth elements [!] while still noting that the lanthanides run from 57–71.

The 48 volumes of The Handbook on the Physics and Chemistry of Rare Earths (1978–2015+), which has Sc, Y and the lanthanides within its scope (Elsevier 2016), runs to more than 25,000 pages and is the longest continuously running series of books on any periodic table category that I'm aware of.

Conclusion
Of the d-block elements, only those in groups 4–11 have a well established reputation for exhibiting the important characteristics of transition metals. In the literature, the group 3 metals Sc and Y are routinely compared or treated with the lanthanides in terms of their chemical, metallurgical and physical properties.

Sure, when scandium is counted as a transition metal, this is rightly done in light of its electron configuration. And this needs to be noted in our transition metal article.

But the way we categorise the elements in our periodic table is not primarily based on electron configurations. Rather, we have a categorization scheme that is informed by overall chemical, metallurgical and physical properties. This needs to made clear in the caption to the periodic table in the lede, as per the example.

Viewed this way, the transition metal colouring of scandium and yttrium in our periodic table is damned incongruous. Scandium is more accurately coloured as a rare earth metal (which is an IUPAC approved category), along with yttrium and the lanthanides. This would not mean that scandium and yttrium are not transition metals; it only means that in the case of our colour-coded periodic table we choose to show the more representative category.

Similar to The Encyclopedia Britannica Online table, our rare earth metals category could read, "Rare earth metal (lanthanides 57–71)" or "Rare earths (lanthanides 57–71)" as I think it's worth retaining some mention of the lanthanides.

Actinium should remain coloured as an actinide. I mention this in the event that you're wondering why it shouldn't be coloured as a rare earth metal given it's similar to lanthanum in its comportment. Actinium and the actinides are worth retaining as a separate category in recognition of the radioactivity that characterizes the entire series, and the chemical effects this can induce in solids and solutions (Nash & Braley 2001, p. 13). Actinium, in particular, is an intensely radioactive metal, so much so that this contributes to its reactivity and makes it difficult to study in even milligram amounts (Katz & Seaborg 1957, p. 11; Cotton et al. 1999, p. 1142). The relativistic effects that become increasingly prominent in this part of the periodic table (Dholabhai 2008, p. 2) are another consideration.

References

Connelly NG, Damhus T, Hartshorn RM & Hutton AT 2005, Nomenclature of Inorganic Chemistry: IUPAC Recommendations 2005, RSC Publishing, Cambridge
Cotton FA, Wilkinson G, Murillo CA & Bochmann M 1999, Advanced Inorganic Chemistry, 6th ed., John Wiley & Sons, New York
Cotton FA 2000, "A millennial overview of transition metal chemistry", Journal of the Chemical Society, Dalton Transactions, pp. 1961–1968
Cotton FA 2014, Transition element, in Encyclopædia Britannica Online,
Cotton S 2006, Lanthanide and Actinide Chemistry, John Wiley & Sons, New York
Cotton S 2011, "Scandium, Yttrium & the Lanthanides: Inorganic & Coordination Chemistry", in Encyclopedia of Inorganic and Bioinorganic Chemistry, John Wiley & Sons, New York
Cotton S & Harrowfield JM 2012, "Lanthanides: Coordination chemistry", in DA Attwood, The Rare Earth Elements: Fundamentals and Applications, John Wiley & Sons, Chichester
Dholabhai PP 2008, "Probing the 5f electrons: A relativistic DFT study of americium surfaces", PhD thesis, University of Texas at Arlington, Proquest, Ann Arbor
Earnshaw A & Harrington TJ 1973, The Chemistry of the Transition elements, Clarendon Press, Oxford
Elsevier BV 2016, "Publisher Summary", Handbook on the Physics and Chemistry of Rare Earths, vol. 1
Greenwood NN & Earnshaw A 2002, Chemistry of the Elements, 2nd ed., Butterworth Heinemann, Oxford
Gschneidner Jr. KA 1975, "Physical metallurgy", in CT Horovitz et al. (eds), Scandium: Its Occurrence, Chemistry, Physics, Metallurgy, Biology and Technology, Academic Press, London, pp. 76–110
Jensen WB 1986, "Classification, Symmetry and the Periodic Table", Computers & Mathematics with Applications, vol. 12B, no. I/2, pp. 487–510
Katz JJ & Seaborg GT 1957, The Chemistry of the Actinide Elements", Methuen, London
Nash KL & Braley JC 2001, "Chemistry of radioactive materials in the nuclear fuel cycle", in KL Nash & GJ Lumetta (eds) 0000, Advanced Separation Techniques for Nuclear Fuel Reprocessing and Radioactive Waste Treatment, Woodhead Publishing, Oxford, pp. 3‒22
Rayner-Canham G & Overton T 2006, Descriptive Inorganic Chemistry, 4th ed., WH Freeman, New York, pp. 484–485
Russell AM & Lee KL 2005, Structure Property Relations in Nonferrous Metals, John Wiley & Sons, New York
The Red Book—see Connelly et al.

Sandbh (talk) 02:20, 13 January 2016 (UTC)

This is an interesting posting, indeed. I want to note a couple of points re group 3 (i.e., not a substantial re):

From Greenwood, another quote would be this: "Because of this, although each member of this group is the first member of a transition series, its chemistry is largely atypical of the transition elements." So, they do not question, while mentioning that some others do, that group 3 also belongs to the transition metals set. I think the word "proper" mostly relied not on properties alone, but also on group 3 being split from the rest of the d block, as they use the Sc-Y-La-Ac group 3 layout.

Cotton's arguments are not criteria; that is concluded from words "typically" and so on that he uses. As they stand, they're not universal: the multiple OS criterion does not apply to neighboring zirconium, and zirconium also commonly forms colorless/white compounds; both Y and Zr are paramagnetic; and this falls in line with the idea of how transition elements represent an actual transition, with group 3 standing at the very beginning of it.

Viewed this way, the current coloring matches the profile of the elements in question. Another point, which plays a greater role to me, is, the proposed scheme is not as user-friendly, as I will describe below. It must be remembered that Wikipedia is oriented towards a wide audience, far wider than the G&E book, for example. Since we (suppose) have two possible variants, the current scheme and the proposed scheme, and accuracy is considered fulfilled for both, it may be a better reason to stay with the current coloring because it is easier to understand. "This would not mean that scandium and yttrium are not transition metals" -- for many readers, it would mean exactly this. Many won't read; some will, and won't understand it. The current scheme has a more subtle problem, but the fact two group 3 elements are TMs and two aren't may ignite some thinking. We still have a very common category for the 4f elements (lanthanides). That said, the current scheme is okay. The proposed scheme, apart from its advantages, also has its great disadvantage: it visually unquestionably excludes group 3 from the TM series. Wider audience does not mean we have to simplify our material; but we need to make an editorial decision either way and both alternatives are correct. In such a situation, I think the current scheme is preferred; but I'd like to hear your reception to this thesis.--R8R (talk) 12:04, 14 January 2016 (UTC)
- Actually I think I'm with Sandbh this time. Scandium and yttrium do indeed appear to be much closer to the lanthanides than the rest of the transition metals, so I think it makes more sense to group them together to form the rare earth metals – a term that I think more people know than "lanthanides" today, judging by how often it occurs in the news. (Yes, I know the lanthanides probably are named as such in the periodic table in your first chemistry textbook, but I really doubt they will be mentioned for a long, long while. Poor lanthanides. They're so pretty!) Such a classification makes it easier to write about chemistry. If you look at Cotton's book, for instance, he covers Y explicitly together with all the lanthanides, as it is so close in behaviour to a heavy lanthanide. He covers Sc as a special case in its own chapter, but then he does the same for Pm, whose only problem is its radioactivity; so I think this shows that Sc's specialness mostly comes from it being so small, and that indeed it simply acts like a mini-Lu. (OTOH, he covers the actinides separately, because the radioactivity common to all of them does make a difference, and the increased relativistic effects play a huge role in the chemistry of these elements.)
- I think it is not too much of a demand on our categories that if we place element X into category Y, category Y must be the best possible fit for element X's properties. In particular, if there is a category Z that fits the properties of element X better, then it should be moved to category Z. Thus, the way I see it, Sc and Y are much closer to the lanthanides than the transition metals they currently are grouped with, so they should be moved to be categorised together with the lanthanides. This is even better supported by the fact that there is a standard name for scandium, yttrium, and the lanthanides: the "rare earth metals". (It's even IUPAC-approved!) Clearly, this categorisation has been thought to be needed by many reliable sources.
- I think getting the reader to follow the natural overlapping of these categories is a lost cause. Is lutetium a transition metal? If you follow the table explicitly, it isn't. If you follow the electron-configuration definition, it most certainly is. So already we have this problem. When faced with this, we should pick the most representative categories. According to the IUPAC 2005 Red Book, astatine is a halogen. Yet this is a poor fit for it, which is why we moved the halogens to simply being a group and not a category. According to the Red Book again, N is a pnictogen and O is a chalcogen; but you can bet that if I ever get around to rewriting those two articles, I am going to treat them separately as special cases and refer to the pnictogens and chalcogens as simply P–Bi and S–Po respectively (following what appears to be more common among chemists), because these (as specialist categories) are poor fits for N and O respectively. Their behaviour is too different!
- There are so many possible categories not shown on our table. We have chosen to limit ourselves to just ten, with one more that basically is "don't know". We had better then carve up the table to keep the most similar elements together.
- For the same reason, group 12 should be placed with the post-transition metals. Actually I might even advocate colouring Cn as a post-transition metal for now, as we know that physically acts like its lighter congeners. It is only the chemistry that is expected to be that of a transition metal, and we do not know that yet. All the experimental evidence we have is on physical properties, which fall on the side of PTM.
- (This is also why I am fine with keeping the status quo on the nonmetals; the polyatomic/diatomic/monatomic distinction does indeed correlate very well with many other properties, so that each element fits better in its own category than any other. I would also think that separating iodine from the other three halogens would be a grave mistake. This is one of the model examples of great group trends, at least if you ask astatine to politely decay before you begin your lecture. And I think dumping them all together results in a category that is much more diverse than the others: look at the dramatic difference between fluorine and selenium, two extreme cases. If you compared the extreme members of any other category, it wouldn't be that drastic a difference.)
- Naturally we should still retain mention of the lanthanides as being a thing, but increasingly I am thinking that the category (and main flagship article for it, with the detailed chemistry) should be the rare earths. Lanthanides could even be simply a redirect to a section of the rare earths, as they overlap so much. You'll notice that even in Greenwood and Earnshaw's attempt to cover group 3 separately from the lanthanides and actinides, he kind of cheats by looking at La in both the group 3 and lanthanide chapters. (He can get away with this more easily for Ac, covering it mostly only in the group 3 chapter, as that group's chemistry is more diverse.) Double sharp (talk) 14:07, 14 January 2016 (UTC)
  - P.S. I'm sorry for always referring to Greenwood and Earnshaw 1st edition! The reason is that I just can't seem to find my copy of the 2nd edition anywhere, and I've been looking for a while. It'll probably turn up eventually, but for now I'm using this. If my memory serves me right, details have changed on just about every page, but the general structure is intact, so it should be safe to use this on categorisation topics. Double sharp (talk) 14:09, 14 January 2016 (UTC)

Four new elements

7th periode is now completed. Someone should add info... --Obsuser (talk) 21:13, 5 January 2016 (UTC)

It's mentioned several times, earliest is the last paragraph of the lead section (including mentioning the recnet-news aspect) and then with more detail at the end of the History section. What additional info would you like to see? Alternately, you should be able to edit the article if you have some ideas. DMacks (talk) 21:33, 5 January 2016 (UTC)

I got news on 5th January 2016 and IUPAC formally recognized them about 5 days earlier. My bad. --Obsuser (talk) 22:55, 15 January 2016 (UTC)

rm Type I-II-III references

I have started to remove all Type I-II-III references (namings for group 3 variants):

- They are OR (no source lists them as such)

- Their categorisation base is broken (like: Type a = by color, type z = by length)

- There is no need or usefulness for any reader to shortify these concepts into a local code. Essentially saying "Group 3 = ..." does the job.

- More cleanup=clarification can be done.

Must say, very disappointing having to enforce this upon Sandbh's edits. -DePiep (talk) 00:20, 24 January 2016 (UTC)

Origin of the Sc|Y|*|** table

Any idea who originated this form?

I was looking at The Internet Database of Periodic Tables today, to so how far this version went back. The first tables that caught my eye were Seaborg's of 1944 and 1945. I mention him because his actinide hypothesis was quite influential. Before that there is Deming's table of 1923 which popularized the 18-column form. Earlier yet there is Meyer's Periodisches System der Elemente of 1918 but this is an 8-/18-column hybrid. It may be that although there were predecessors, Deming's 1923 table was the candle that lit the fire. Or will my question be similar to attempting to find the source of the Nile/Amazon? Sandbh (talk) 11:37, 21 January 2016 (UTC)

I added a note (#12) to the article that addresses this question. Sandbh (talk) 12:04, 22 January 2016 (UTC)

Not read the sources yet. Anyway: Graphs-By-Heros are not defining:

- Mendeleev put uranium in group VI (Reihe 12). Th in Reihe 12 (group IV). You maintain?

Mendeleev's assignment of Th to group IV and U to group VI was a reasonable decision in its time. But effectively no one has been doing this since Seaborg's actinide hypothesis became universally adopted just after World War Two. Sandbh (talk) 10:25, 27 January 2016 (UTC)

- Seaborg 1946 did not bother about the graphic issue. Nor about group 3 composition.

Agree. Neither has IUPAC bothered with the graphical issue. Nevertheless, the Sc|Y|*|** table is one of the three most common forms. Sandbh (talk) 10:25, 27 January 2016 (UTC)

S, you float from "PT in RS x shows it [so proof]"to "[Fringe I found] defines it" (quite a point here: what are actually the sources for all those wallpapers?).

Again, Sandbh, you abuse editors energy to make your moving fog point: that a graph in an (otherwise) RS proves "group3=32 elements". That is your core thinking error. Eric Scerri does not even mention your OR assumption.

Please take note of the 'abuse of editors energy' thng. -DePiep (talk) 23:18, 23 January 2016 (UTC)

DePiep, let me be clear on what you are saying. I will do this in small questions so that there is no confusion:

Q1. I think you're saying that a Sc|Y|*|** table, from a graphical point of view, implies there are 32 elements in group 3. Is that right? Sandbh (talk) 10:23, 24 January 2016 (UTC)

A1: re "from a graphical point of view" No, not by some "view". BY FACTUAL PRESENTATION. There is no choice for the reader. The graph says: "column header 3 = 32 elements". -DePiep (talk) 22:14, 24 January 2016 (UTC)

Q2. Do you think that showing 32 elements in group 3 is factually wrong? Sandbh (talk) 02:18, 25 January 2016 (UTC)

A2: It was great, in 1946! How could I disagree with Seaborg?

Now back to your point: when do you digest & apply my answer? -DePiep (talk) 22:09, 25 January 2016 (UTC)

I'm trying to digest your answer by seeing if I can follow your logic. I'm doing this by asking more questions. It's a slow process but will be worth it if both of us can be 100% clear on each other's position. Sandbh (talk) 23:13, 25 January 2016 (UTC)

I've answered dozens of times, including A1 here: A Sc|Y|*|** table states (not just suggests or optionises) that there are 32 elements in group 3. Irrespective on whether drawn in 32-col or 18-col format. It was introduced ca 1946 by Seaborg to allow for actinides/f-block etc. By then is was great, by today it is historical. You (Sandbh) may have found two or three sources that actually base that group 3 has 32 elements (after I pushed you, remember), but that only moves the 3=32 fact from "wrong" into "fringe". When you sourced the other two group-3-options (20 sources), you yourslef did not even find or noted that 3=32 is a viable third statement.

Confusingly enough (for you that is) you keep mixing this topic with the "18- or 32-col PT" thing. A3: Find a wall, bang your head 3 times against it, then leave this mixing behind. -DePiep (talk) 23:32, 25 January 2016 (UTC)

Q3. Are the following 14 sources, which refer to the Ln and An being part of group 3, reliable(?):

As noted by User:Burzuchius, "In Russian chemical literature, the statement that all the lanthanides and actinides belong to the "transitional subgroup of group III" (=group 3, as opposed to the "main subgroup of group III"=group 13) is frequent; the Great Soviet Encyclopedia and the Chemical Encyclopedia state so."

Fine (1978, pp. 702–707) has a six page section called THE 32 ELEMENTS IN III B [his formatting, not mine] which includes a Sc|Y|*|** periodic table with the 32 elements in question shaded. Fine LW 1978, Chemistry, 2nd ed., The Williams & Wilkins Company, Baltimore

"Scandium (Sc), yttrium (Y), the lanthanides and actinides constitute subgroup B of group III in the periodic table."—Luckey TD & Venugopal B 1978, Metal toxicity in mammals: Chemical toxicity of metals and metalloids, Plenum Press, p. 101

"Both the lanthanoids and actinoids are considered to be part of group IIIB, the scandium subgroup." ; "The lanthanoids and actinoids…are often counted with group IIIB."—Russell JB 1980 General chemistry, McGraw-Hill Higher Education, pp. 161, 641

"The carbides of Group 3, ie, Sc, Y, the lanthanides, and the actinides, are opaque."—Stoll WM & Santhanam AT 1992, "Carbides (Industrial Hard)", in Kirk-Othmer Encyclopedia of Chemical Technology, 4th ed., vol. 4, Bearing Materials to Carbon, John Wiley & Sons, New York, p. 844

Williams et al. (1996, p. 10) features a periodic table with the f block elements marked as "Lanthanides (Group 3)" and "Actinides (Group 3)".—Williams RJP et al. 1996, The natural selection of the chemical elements: The environment and life's chemistry, Clarendon Press

"The 28 lanthanides and actinides together make up about one quarter of the periodic system as it is now known, with 109+ elements. Together with the four related elements Sc, Y, La and Ac, they all belong to transition group III, which is thus the largest subgroup in the period table."—Wiberg N 2001, Inorganic chemistry, Academic Press, p. 1645

"The lanthanides and actinide elements are all metallic and are formally members of Group 3 of the Periodic Table."—Barrett J 2002, Atomic structure and periodicity,' The Royal Society of Chemistry, Hoboken, New Jersey, p. 80

"Group 3 elements…include the lanthanides and actinides."—Byrne CH 2002, "Speciation in seawater", in AM Ure & CM Davidson (eds), Chemical speciation in the environment, Blackwell Science, pp. 322–357 (332)

"Modern group numbering runs from 1 to 18, with the f blocks being subsumed into group 3."—Cox PA 2002, Inorganic Chemistry, 2nd ed., Bios Scientific Publishers, p. 11

Quadbeck-Seeger (2007) shows a 32-column table, and says in a footnote, "all lanthanides and actinides belong to group 3."—Quadbeck-Seeger HJ 2007, World of the Elements: Elements of the World, Wiley-VCH, Weinheim, inside cover

Enghag (2008, p. 65) uses a Sc|Y|La|Ac table and above the lanthanides he says, "Lanthanides (the 14 elements between lanthanum and hafnium (period 6, group 3)". Above the actinides he says, "Actinides (the 14 elements after actinium, thorium-lawrencium (period 7, group 3)."—Enghag P 2008, Encyclopedia of the Elements, Wiley-VCH, Weinheim

"The 30…elements…at the bottom of the periodic table belong to the lanthanide and actinide series found in group 3 of the periodic table."—Ganfalvi G 2011, "Heavy metals, trace elements and their cellular effects", in G Ganfalvi (ed.), Cellular effects of heavy metals, Springer-Science+Business Media, pp. 3–28 (7)

— Sandbh (talk) 05:51, 26 January 2016 (UTC)

You keep jumping from one foot on the other. Have you decided on whether this graph defines group 3 or just suggests it (see Q1-A1)? At the moment, the "suggestion" is relegated to reference #13 only. (Background of this daily alternating is that you keep relating the two issues. If you want to get things clear, it's your turn to conclude). -DePiep (talk) 11:27, 27 January 2016 (UTC)

I would personally say that drawing Sc/Y/*/** absolutely implies that all 15 lanthanides and all 15 actinides are group 3. (Is this a valid characterisation of your stand, DePiep?) I think that the above is evidence that 12 of these 14 sources (a rather significant number) intentionally wanted to show 32 elements in group 3, so that this implication of Sc/Y/*/** would have to be taken seriously as a legitimate variant (albeit not a good one). However, if one looks at the periodic tables in Holleman and Wiberg, as well as Enghag, we get a strange inconsistency. They use a Sc/Y/La/Ac table, and yet treat group 3 as having 32 elements. One can't have it both ways. (My favourite source, Greenwood and Earnshaw, is consistently Sc/Y/La/Ac. It disappoints me somewhat that the German standard text contains this inconsistency...) Double sharp (talk) 11:45, 27 January 2016 (UTC)

A group does not actually exist; it's a theoretical construct invented by us humans for classification purposes. As such, we humans can define the term to be whatever we want.

 2              3               4
|Ca| |Sc                    |  |Ti|
|Sr| |Y                     |  |Zr|
|Ba| |La Ce Pr ....... Yb Lu|  |Hf|

An example of how this could be. This is a self-consistent model.--R8R (talk) 13:36, 27 January 2016 (UTC)

Yes, that is consistent. What is not consistent is putting La alone under Y in group 3, and then proclaiming that the other 14 lanthanides are also members of group 3. Double sharp (talk) 14:31, 27 January 2016 (UTC)

As R8R is drawing the group 3 here [completed into a PT], it defines 32 elements in there. If R8R wants to convey some other 'theoretical construct', he should draw a different graphical construct. -DePiep (talk) 16:07, 27 January 2016 (UTC)

Well, the two Russian sources I have mentioned (the Great Soviet Encyclopedia and the Chemical Encyclopedia) are also somewhat inconsistent: they consider the lanthanides and actinides to be group III elements in the text and in the 8-column table, but they also show the 32-column Sc-Y-La-Ac form, and in that table, the label "IIIb" is placed above the Sc column only.Burzuchius (talk) 21:31, 27 January 2016 (UTC)

Thanks for detailing this. Not devastating for these encyclopedias (it happens 'most commonly, for dozens of years, re group 3). But in this thread it is core: text-does-not-match-graph. -DePiep (talk) 00:23, 28 January 2016 (UTC)

If I was a general reader I would agree with Double sharp. Drawing Sc/Y/*/** will nearly always imply that all 15 lanthanides and all 15 actinides are in group 3. Greenwood & Earnshaw (2nd ed.) struggle a bit with this. In their periodic table each element box is 11 mm × 11 mm. In the two boxes under Y they show La* and Ac†. But each of these boxes is only 10mm wide. There is are two empty pillboxes between La and Hf and between Ac and Rf that are each 1 mm wide and 11 mm high. *Ce to Lu, and †Th to Lr are shown at the foot of their table. Thus it looks like they say 32 elements in group 3 or do they? In their mighty text they imply that only Sc, Y, La and Ac are in group 3. Sandbh (talk) 10:39, 28 January 2016 (UTC)

Saw this only just now. Sandbh, don't get distracted into a mud. That is IUPAC behaviour. -DePiep (talk) 20:51, 28 January 2016 (UTC)

Q4. Placeholder for a question I haven't worked out yet

"The lanthanides and actinides have been of so little relative importance that they have not been given group numbers."—Dickerson et al. 1979, Chemical principles, Benjamin/Cummings Publishing Company, p. 268

"There are no group numbers assigned to this portion of the table, because similarities within each period are more important than any vertical relationships."—Siebring BR & Schaff ME 1980, General chemistry, Wadsworth Publishing Company, p. 128

"The lanthanides and actinides are metallic, and they give up a number of electrons equal to their group number, IIIB."—Becker RS & Wentworth WE 1989, General chemistry, Houghton Mifflin, p. 202

"The f block does not have group numbers."—Olmsted J & Williams G 2002, Chemistry: A molecular science, 3rd ed., John Wiley & Sons, p. 292

"The inner transition elements (also called lanthanides and actinides) are metals that have no group numbers."—Hughes KJ & Kelter PB 2002, Student study guide to accompany Chemistry: A world of choices, McGraw-Hill, pp. 28–29

"We'd like to resume with a discussion of the lanthanide and actinide elements. These elements, while assigned no group numbers, are…shown below the main body of the periodic table."—Krishnamurthy N & Gupta CK 2004, Extractive metallurgy of rare earths, CRC Press, p. 460

"In the case of the 15LaAc form…the 30 elements are treated not as a separate independent electronic block but rather as degenerate members of group 3 of the d-block. The two boxes below Sc and Y…contain either the atomic numbers 57–71 and 89–103 or the symbols La–Lu and Ac–Lr, respectively, thus indicating that all 30 of the elements in the footnote belong in just those two boxes. Expanding such a table into a 32 column table would require one to stretch the boxes for Sc and Y so that they span all 15 of the inserted columns. This interpretation goes back to the 1920s and the original electronic interpretation of the so-called rare earth elements, as shown in the 8-column table in Figure 1 taken from Ephraim’s textbook of 1929 (5), and was later reformatted in terms of an 18-column table and extended to the actinoids by Seaborg (6). In the case of the lanthanoids it was based on the assumption that all of them had, as per Sc and Y, a common (n – 1)d¹ns² valence configuration and a maximum possible oxidation state of 3+, their only differences being the presence of a variable, but chemically insignificant, [noble gas](n – 2)f^xcore. As shown in my original article, all of these assumptions are now known to be false (7). Many of these elements have (n – 2)f^xns² valence configurations and exhibit maximum oxidation states greater than 3+, thus making their assignment to group 3 of the d-block chemical nonsense. 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."—Jensen WB 2008, "The Periodic Table: Facts or Committees?", Journal of Chemical Education, vol. 85, no. 11, 1491–1492

— Sandbh (talk) 22:30, 27 January 2016 (UTC)

Sandbh, you're expected to respond to my 11:27, 27 January 2016 post. (If you got distracted by intermediate posts possibly OT: don't let yourself be). DePiep -00:14, 28 January 2016 (UTC)

Yep. I expect to be able to do this later today. Sandbh (talk) 03:41, 28 January 2016 (UTC)

PT graph versus structure

Won't explain it too much. A diff graphic PT is NOT the same as a diff structure PT. (eg bg colors, font type, 18/32 cols versus Janet's Left Step, spiral, ADOMAH). Ask me if you do not get this. (I edited it this way, btw) -DePiep (talk) 00:38, 24 January 2016 (UTC)

DePiep, in general I like your edits. Will have a closer look later. Sandbh (talk) 02:50, 24 January 2016 (UTC)

I still like them. I tidied the Group 3 constitution variants section, removed some redundant text and fixed some mistakes. How does it look now? Sandbh (talk) 11:41, 24 January 2016 (UTC)

Like what you like. Won't help our Reader. Just say: "Group 3 = ...". Now repeat. -DePiep (talk) 22:11, 24 January 2016 (UTC)

Article section Periodic_table#Group_3_constitution_variants would be great when presented in 32-col form. -DePiep (talk) 01:33, 31 January 2016 (UTC)

Downwards and backwards

Today Sandbh pushed their /sandboox version of this article into live. Repeatedly I have pointed to flaws and errors in this version, but for some months the editor did not bother to reply or base their changes on sound arguments. In short, and as an incomplete list, this is wrong in the article (all topics + arguments can be found above).

Using the wording "Standard form" and "Long form" (eg in top image): not sourced (=OR), not correct, and misleading. On top of this, there are two viable forms for group 3, and nowhere is explained why this version would be "standard". Actually, the current "standard form" (ie mostly used in serious sources) is an other one (namely, putting 32 elements in group 3—incorrectly, see below).

Good point. Scerri (The Periodic Table, 2007, p. 21) says, "The standard form of the periodic table has also undergone some minor changes regarding the elements that mark the beginning of the third and fourth rows of the transition elements. Whereas older periodic tables show these elements to be lanthanum (57) and actinium (89), more recent experimental evidence and analysis have put lutetium (71) and lawrencium (103) in their places. It is also interesting to note that some even older periodic tables based on macroscopic properties had anticipated these changes." How does that look? Sandbh (talk) 09:26, 25 December 2015 (UTC)

I've edited the article to emphasise that the concept of a "standard" form refers to the 18-column form, of which there are three main variants. Does this help? Sandbh (talk) 23:24, 25 December 2015 (UTC)

"Does this help" - No, no 'help'. "Standard form" is a useless, misguiding old concept. There is no "standard" from, and no authority can claim it to be (Which is why you can not source it). The reader is helped into a trainaccident this way, because you introduce the subliminal point: what is not standard, then? Just leave out those relative, indecisive and outdated judgemental wording. Don't use = no need to explain. Oh and claiming a Standard unbsourced is OR/POV. -DePiep (talk) 08:23, 5 January 2016 (UTC)

The article sources Eric Scerri on this point and his book on the history and significance of the periodic table. Sandbh (talk) 22:34, 5 January 2016 (UTC)

Another OR. Scerri does not define "the standard", let alone in a way you do here. The word "standard" form is used for many variants (historical ones included), even covering the wrong "third" variant. In situations it also refers to the scientific form (be it 18- or 32-colomn) to differentiate it from scientific variants like Janet's Left Step. As such it is useless as an identifier for a particular form. Proof: the Scerri source you point to says: "The standard form of the PT has also undergone some minor changes re the elements re.." (i.e., not stable in history), all this in an larger description of (1) the single law of periodicity, 2. graphic variants, and 3. scientific variants (together ~700 he says). So Scerri does not define this "standard". And as we know, Scerri does not so consistently over his publishings. -DePiep (talk) 08:53, 8 January 2016 (UTC)

In section "#Different periodic tables": introducing "Type I, II, III" denominations. These do not exist as such in literature (unsourced, so OR). There is no need to deviate from descriptive wording like "Group 3 is ...".

I added a sentence to say that these labels (of convenience) are used only for the purposes of the article. Sandbh (talk) 11:18, 25 December 2015 (UTC)

Wrong classification setup. After the two well sourced, structural variants having Group 3 is SC, Y, La, Ac en Group 3 = Sc, Y, Lu, Lr, a third from appears that is not sourced and is not a new structural variant. Tellingly, it is labeled "[Group 3 =] Sc, Y, and markers": markers are elements? At best, the third form can be described as a sloppy, careless version. But actually it is a wrong version (nowhere in the sources it is claimed that group 3 has 32 elements; and so of course nowhere in the article can this be referenced or described). This is more like dumb, uncritically copying the sloppyness of a source into prominence. I checked two sources Housecroft and (not in the article but used on this talkpage) the IUPAC Red Book: none states that that is a description of group 3. Tellingly, Housecroft chapters skip groups 3–12. Mixing up two scientific variants with a third graphic droodle is amateuristic approach.

You may have missed my previous post to this page. Fine (1978, pp. 702–707) has a six page section called THE 32 ELEMENTS IN III B [his formatting, not mine] which includes a Type III periodic table with the 32 elements in question shaded.

Fine LW 1978, Chemistry, 2nd ed., The Williams & Wilkins Company, Baltimore [post by Sandbh, I assume]

And this singles source [fringe] you [POV] promote [OR] into mainstage science, even transposing Fine's statement to be the base for all other such PTs like IUPAC? -DePiep (talk) 08:13, 5 January 2016 (UTC)

No, the practice of extending Group 3 membership to rope in the lanthanides and actinides is not fringe, although Jensen disparages it as noted in the article per your concerns. Here some further examples from the literature: "The lanthanides and actinide elements are all metallic and are formally members of Group 3 of the Periodic Table." Barrett J 2002, Atomic structure and periodicity, The Royal Society of Chemistry, Hoboken, New Jersey, p. 80 • "The carbides of Group 3, ie, Sc, Y, the lanthanides, and the actinides, are opaque." Stoll WM & Santhanam AT 1992, 'Carbides (Industrial Hard)', in Kirk-Othmer Encyclopedia of Chemical Technology, 4th ed., vol. 4, Bearing Materials to Carbon, John Wiley & Sons, New York, p. 844 Sandbh (talk) 22:19, 5 January 2016 (UTC)

Wait wait. So you have this one (one) source that actually does describe group 3 being 32-element, and it is not in the article? At least, do you admit/agree that the current sources (including Housecroft I could check) do not support the claim? Those sources must be removed then. -DePiep (talk) 08:39, 5 January 2016 (UTC)

The current sources are examples of type III Sc|Y|*|** tables. Whether or not they address or imply that group 3 is comprised of 32 elements is irrelevant since they are cited only to illustrate examples of the type III table. As explained in the article, Jensen has criticised some presentations of type III tables for implying that all the Ln fit in the single box below Y. Sandbh (talk) 23:55, 5 January 2016 (UTC)

This describes your sin. Their graphs state group 3 = 32 elements, and their text does not source it. From this, you conclude these 'sources' "define" a new variant. Qoud non. -DePiep (talk) 08:40, 13 January 2016 (UTC)

Their graphs can be read to imply that group 3 has 32 elements or they can be read to imply that 57–71 and 89–103 fit between the s-block and the rest of the d-block, in an ambiguous manner. Either way I'm only describing a variant, warts and all, that is widely used in the literature, as observed by Clark and White (2008) in "The Flyleaf Periodic Table", Journal of Chemical Education 85 (4): 497. This article prompted a flurry of responses from other authors including Jensen, Scerri and Phillip Stewart (of Chemical Galaxy fame) none of whom criticized Clark and White's finding that there were three main types of periodic table, including Sc|Y|*|**. Sandbh (talk) 06:20, 16 January 2016 (UTC)

"Their graphs can be read to imply ... or" - no, not 'can be'. 'Must be' is the right wording. These graphs undisputedly, unambiguously state column3/group3=32 elements. You can not talk some out of it.

"none of whom criticized" - that is not enough. Even stronger, it supports the claim that group3=32 elements is not sourced. -DePiep (talk) 10:13, 17 January 2016 (UTC)

Here are two more examples of authors who say there are 32 elements in group 3: Enghag P 2008, Encyclopedia of the Elements, Wiley-VCH, Weinheim, p. 65: He uses a Sc|Y|La|Ac table! Quadbeck-Seeger HJ 2007, World of the Elements: Elements of the World, Wiley-VCH, Weinheim, inside cover: he shows a 32-column table, and says in a footnote, "all lanthanides and actinides belong to group 3". Those two are in addition to the previously mentioned examples (Fine 1978; Barrett 2002; Stoll and Santhanam 1992). I pass no judgement as to the merits of saying group 3 has 32 elements. I simply note this is done by some authors. Sandbh (talk) 11:32, 17 January 2016 (UTC)

From [https://en.wikipedia.org/w/index.php?title=Wikipedia_talk:WikiProject_Elements&diff=698795789&oldid=698794912 from WT:ELEM, continued here:

About 'Quarkonium' News from Eric Scerri - Sandbh

Great. [...]

Second: Scerri announces a IUPAC taskforce (his, so to speak) into the constitution of Group 3. That is good news. I also note that with this, he does not even mention Sc/Y/*/** being group 3. Well, if it takes IUPAC to get rid of it as a serious PT construction, so be it. But we can shaft it on sound grounds today. -DePiep (talk) 02:36, 8 January 2016 (UTC)

The main problem with Sc/Y/*/** is that while you will see people using it, they don't seem to agree what it means. As a result it is difficult to critique it because you cannot start critiquing a form until you are sure what it is supposed to mean. Thus we use Jensen's assumption of its meaning (though you will hear people saying "oh, it's to keep Ln/An together" or "oh, obviously La and Ac are primary since they are the first" or any number of strange things to justify it). Nonetheless, I would still say that from personal experience, the unequivocal Sc/Y/La/Ac beats it in popularity.

As popular as it is, though, we seem to be stuck with it for now. If IUPAC actually makes a decision, though (hopefully on Sc/Y/Lu/Lr), then we could probably get away with downgrading Sc/Y/*/** from "Type III" to an unnumbered form, mentioned due to its history of usage, but as a side thing to be critiqued and immediately thrown out as a thing. Double sharp (talk) 03:30, 8 January 2016 (UTC)

"... what it is supposed to mean". No, there is no question about it: it graphically says that group 3 has 32 elements and that Sc, Y border both their period elements left and right. And 99/100 sources who publish a Sc/Y/*/** do not base that statement on scince but bad editorship (it is not described as such in those same sources that draw Sc/Y/*/**). In this, these are an unRS. The real problem with Sc/Y/*/** is that people here keep using & pushing that drawing as a third, scientific variant for group 3. I oppose, and Scerri does not even mention it (also not in his earlier papers). -DePiep (talk) 08:40, 8 January 2016 (UTC)

The single usage of the 18-column form, omitting the 32-column form completely, is an editorial choice and a POV. I agree with Scerri: as a modest question, please keep atomic numbers in order (done) and give us the 32-column form (not done).

I'll have a look at this. It seems odd not to say anything about the 32-column form in the Different periodic tables section. Sandbh (talk) 10:26, 25 December 2015 (UTC)

32-column PT is not different from its 18-column form. It is the same PT, presented different form. The scientific statements are the same, and must be. Examples of a different PT are : Janet's Lewft Step, ADOMAH, and hundreds of other structural variants. -DePiep (talk) 08:07, 5 January 2016 (UTC)

I've added a 32 column table and accompanying text. Sandbh (talk) 23:34, 26 December 2015 (UTC)

In Russian chemical literature, the statement that all the lanthanides and actinides belong to the "transitional subgroup of group III" (=group 3, as opposed to the "main subgroup of group III"=group 13) is frequent; the Great Soviet Encyclopedia and the Chemical Encyclopedia state so. In Russia, the terms "lanthanides" and "actinides" (or, more frequently, "lanthanoids" and "actinoids") are usually understood to mean Ce to Lu and Th to Lr; but the arrangement of the footnotes in the 8-column table (as R8R Gtrs has already said in some talk pages, it is still common in Russia, slowly being superseded by the 18-column table) may be either 14CeTh or 15LaAc. Hydrogen in Russian 8-column tables is normally shown in groups I and VII; either with full information in group I, parenthesized and without information in group VII, or vice versa.Burzuchius (talk) 20:05, 26 December 2015 (UTC)

Very interesting, Burzuchius. Do these two sources give a base or primary source for this statement? Scientific reasoning? Sandbh is dearly in need of a second source support for these fringe graphics. So far, all sources but one (one) do not support their own wrongful group-3=32-elements presentation.

... but the second part of your answer suggests this: coming from the 8-column PT, adding f-block columns 19–32 may not be that accurately done. All in all, we are not interested in how the elements are drawn into a source's PT, but whether the drawing is conform its textual statements. If not, the drawing is a misleading fraud, and can not count as a 'source' for a 32-element group 3. -DePiep (talk) 08:32, 5 January 2016 (UTC)

I mean the explicit statement, not just the drawings. For example: "The rare earth elements are a family of 17 elements of group III of the periodic system, comprising scandium, yttrium, lanthanum and the lanthanoids..." (Chemical Encyclopedia, 1994 [1]). I think the reasoning is the following: the lanthanides are very similar in their properties, and they all have the common oxidation state +3. Some of them can have +4, especially cerium, but they are not very much like group IV. After all, the rule "maximal oxidation state is equal to the group number" already has exceptions in the 8-column table: Cu, Ag, Au are in group I, but they can have oxidation states more than +1. And the principle "one cell, one element" in the 8-column PT is violated by the triads in group VIII. The actinides are placed in group III by analogy with the lanthanides, although the early actinides (Th, Pa, U, Np, Pu) are not very much like lanthanides.Burzuchius (talk) 13:33, 5 January 2016 (UTC)

For sake of the argument, I assume your 'I think the reasoning is ...' (OR) can be replaced by the original sources. That says by now we have two sources that claim so explicitly (that is: sourced as a scientific statement). btw, the Ce exception and others is weighed quite heavy elsewhere on this page. This assumption does not validate presenting the group 3 = Sc/Y/*/** variant as mainstream PT. Already a dozen sources (Scerri, Jensen come to mind) do explicitly not mention this one, which can be counted as a counter-source (so sources: going below zero this way!).

I state (working hypothesis) that 99/100 PT's that show Sc/Y/*/** do so out of sloppyness/unknowingly. To make matters worse, these PT's do not re-graph into 32-column form without exposing the fraud. This is bad for every reader and scolar in the field. -DePiep (talk) 09:06, 8 January 2016 (UTC)

The article keeps pushing (silently, but predictably it will be added later) that group 4–group 17 continue below into the footnoted elements.

DePiep (talk) 09:00, 25 December 2015 (UTC)

I don't think f-block group numbers (however these look) will ever happen unless elements occupying the next row of the f-block are synthesised i.e. in the vicinity of 141 onwards. Sandbh (talk) 11:49, 25 December 2015 (UTC)

It disturbs me that the group 3 issue is covered twice: once in "Common form variants" and again in "Period 6 and 7 elements in group 3". Double sharp (talk) 08:17, 5 January 2016 (UTC)

This may be unavoidable since the reason why there are three common types of 18-column table arises from the group 3 issue hence it is mentioned in the first section. The controversy is then explored in the second section. I'll have another look at this. Sandbh (talk) 00:00, 6 January 2016 (UTC)

Sandbh there are three common types of 18-column table arises from the group 3 issue - Nonsense. Unsourced, synthesis, incorrect synthesis (because you are mixing up two grouping 'rules' into one set), no consensus, mixing up editorial chooices with scientific bases, introducing fringe for mainstream, bad and judgemental qualifying (eg pushing 'common'), and so bad loads onto the reader. -DePiep (talk) 09:36, 6 January 2016 (UTC)

What changes would you like to see in the article? Sandbh (talk) 10:29, 6 January 2016 (UTC)

1. Remove the third 'variant' (Sc/Y/*/**) completely from the article. Not a mainsteam scientific variant, more a bad graphic inherited habit. Lacks sources. Could be a section in PT History, adding: Why does your classroom PT not look like WP's?

DePiep, is this still your position? Sandbh (talk) 10:53, 2 February 2016 (UTC)

2. Throughout the article(s), maintain a split within all 'variants' wrt scientific variant (ie structurally different: like Janet's), and graphically different (like 18/32-col for the same group3=Sc/Y/Lu/La PT). Those graph variants should be reduced to a minimum, basically saying in this article: "these two graphs (18, 32) are the same PT".

I believe this has been done? Sandbh (talk) 10:53, 2 February 2016 (UTC)

3. (Have not checked whether this is done bad today, but we should aim for it:) clearly explain that & why we choose to show the Sc/Y/Lu/La variant as the standard group3 variant (enwiki wide). In a section, not in the lede. Group 3 can have more on this all.

Done Sandbh (talk) 10:53, 2 February 2016 (UTC)

4. Remove "Type X" naming. Is not mainstream, and not needed because the description "group 3 = ..." already says it, and more directly at that. The description (definition) is required anyway.

Done Sandbh (talk) 10:53, 2 February 2016 (UTC)

5. Remove all historical/indecisive/ambiguous/relative graph definitions like long form, standard form, medium-long form, etc. Sources are inconsistent between them, relative naming adds complexity in understanding, it is loaded with historical changes. In short: there is no "standard form". -DePiep (talk) 10:47, 8 January 2016 (UTC)

-DePiep (talk) 10:40, 8 January 2016 (UTC)

In general, the literature refers to 8-column tables as the short form, 18-column tables as the modern, standard, common, popular, medium, or medium long form and 32-column tables as the long or expanded form. I propose to explain this in the article rather than not saying anything at all, given how frequently these terms are encountered. Sandbh (talk) 10:53, 2 February 2016 (UTC)

Thank you DePiep; I'll respond to each of the above items. Sandbh (talk) 11:16, 8 January 2016 (UTC)

Thx. I request we pause this thread for some weeks, because I don't have the time to add serious background for this (it is just telegraph-style now). For more thorough argumentation, I want to re-read the article, the whole thread and use/read linked sources etc. But these weeks I'm bizzy in RL. You are free to ponder the seeds I planted, of course ;-). -DePiep (talk) 11:30, 8 January 2016 (UTC)

Sandbh, another (similar) question here you did not answer. Your pattern? -DePiep (talk) 01:27, 31 January 2016 (UTC)

DiPiep, have I addressed all of your requests/question?

No you have not. Need to ask? Shortcut to Q2: just read & react for starters (I was about to repeat my boilerplate fact but hey). -DePiep (talk) 22:50, 2 February 2016 (UTC)

Remove semi-protection?

Looks like it's been in force for some 5 years now. Perhaps now would be a good time to test the waters again? Palosirkka (talk) 09:04, 15 February 2016 (UTC)

Palosirkka Nah, the article is featured, and we don't want people messing it up. --Fazbear7891 (talk) 02:57, 18 February 2016 (UTC)

Secret chars in Iodine? An injection hack?

In the main table, Element 53, Iodine, has two hidden characters surrounding the abbreviation "I". I copy/pasted them into wordpad direct off the webpage, and they showed up as rectangular boxes, which I believe is the substitute box shown when the font does not have a symbol to display. I pressed CTRL+U, went the the source, and copy/pasted that as well, and the same thing showed up. (Oddly, they show only as spaces in notepad and the source display. Only wordpad showed them as rectangular boxes.)

What are those special chars? Is someone trying a really lame injection hack? Hopefully someone can investigate. DrZygote214 (talk) 06:09, 3 April 2016 (UTC)

The characters are thin spaces -  . I expect they are there since the letter "I" is so thin that without the thinspace to make it wider, it would be very difficult to get your cursor exactly on the "I" in order to click to the article. For comparison, here are two links, first with the thin spaces I and without them I. I suspect the difference in clickability would be even more significant in a smaller font. YBG (talk) 06:33, 3 April 2016 (UTC)

As YBG writes, added to make the click area wider. However, since copy/paste catches them it is a bad trick. Probably should be done by css (<span> or so). -DePiep (talk) 10:23, 3 April 2016 (UTC)

New element names

Today four elements were given official names: elements 113, 115, 117 and 118: ^[1] The table needs to be updated. — Preceding unsigned comment added by Dwisehart (talk • contribs) 20:26, 10 June 2016 (UTC)

From IUPAC: "The IUPAC Inorganic Chemistry Division has reviewed and considered these proposals and recommends these for acceptance. A five-month public review is now set, expiring 8 November 2016, prior to the formal approval by the IUPAC Council." (emphasis added)

Individual articles have already been updated. No more changes about these names on Wikipedia until proposed name become official. Dhrm77 (talk) 20:36, 10 June 2016 (UTC)

Semi-protected edit request on 17 June 2016

This edit request to Periodic table has been answered. Set the |answered= or |ans= parameter to no to reactivate your request.

Add Element number 113, nihonium, Elements 115 and 117, moscovium and tennessine, and Element number 118, oganesson,

http://www.scientificamerican.com/article/4-new-elements-get-names1/ http://iupac.org/cms/wp-content/uploads/2016/06/Press-Release_Naming-Four-New-Elements_8June2016.pdf http://www.nature.com/news/four-new-element-names-proposed-for-periodic-table-1.20069 http://www.bbc.com/news/science-environment-35220823 198.52.13.15 (talk) 09:24, 17 June 2016 (UTC)

Not done Read the IUPAC press release carefully: the elements are not yet named; the names have been suggested, but they will be formally approved later, after November 8.--R8R (talk) 09:35, 17 June 2016 (UTC)

Regarding note 15

If you look at the tripositive ions that make up so much of their chemistry, though, instead of the neutral atoms, Sc/Y/La/Ac looks favoured intsead, as it is always right (Ce³⁺ is [Xe]4f¹, and so on), whereas with Sc/Y/Lu/Lr you have to start counting at zero f electrons. Just a note. (^_^) Double sharp (talk) 08:28, 23 June 2016 (UTC)

Hydrogen

Why is hydrogen sometimes isolated from the rest of the table? 108.66.232.241 (talk) 17:17, 5 November 2016 (UTC)

Please note that talk pages are for discussing how to improve this encyclopedia, no for general discussion of the subject matter. YBG (talk) 21:59, 5 November 2016 (UTC)

Regarding hydrogen in group 1

We mention the reasons for all the placements but the best one? (・・? Anyway, the reason for this one is that if you look at hydrogen, by far the most important part of its chemistry is H⁺, losing an electron, theoretically creating a naked proton (OK, so you never see it because the proton instantly gets solvated) and becoming the foundation of acid–base chemistry. It is markedly unhappy about being an anion in hydrides, because the single proton cannot easily control two electrons, and it is even less happy about being a hydrogen radical. So if we are going to place it in a periodic table, Li is the closest element in the second row. Be, B, N, O, and Ne are strangers to it; C only has the electronegativity in common (the other major properties of group 14, like the tendency to catenate, are totally absent in H – also because carbon needs to share so many electrons to be happy with an octet, whereas H can just shed its only one); and hydrogen is unhappy about having to dress up as a halogen with the electropositive metals (sometimes going so far as to form intermetallic alloy-like compounds with metals instead). Therefore a placement in group 1 reflects an Li-like model of hydrogen chemistry – much better than a C-like model or a F-like-model, and even better than throwing up one's hands in disgust and proclaiming that the periodic law does not apply to this singular case among the elements. Of course it is a "zeroth-row anomaly", even bigger than Li vs Na; there is no "lithium bonding", at least no significant one. But Li is the best fit. Double sharp (talk) 15:43, 30 July 2016 (UTC)

the constitution of group 3 task force

Sigh, not that silly argument again. Of course if you compare the two tables presented without split d-blocks Sc/Y/Lu/Lr wins because it keeps the atomic-number sequence, but that's unfair! Nobody supporting Sc/Y/La/Ac wants to have Ce appear before La in the table! Rather, they mean that the d-block is split, with group 3 (Sc/Y/La/Ac) first, then the lanthanide and actinide series, and then group 4 (Ti/Zr/Hf/Rf). Thus the sequence in period 6 is Cs (under Rb), Ba (under Sr), La (under Y), Ce (under nothing), Pr, etc., Yb, Lu, Hf (under Zr), Ta (under Nb), etc., Rn (under Xe).

If this is the choice being presented, I have no doubt that (1) IUPAC will recommend Sc/Y/Lu/Lr, and (2) the silliness of the argument will prompt everyone to ignore them, and brand Sc/Y/Lu/Lr similarly as a silly choice by association (even if it is not silly in reality). Double sharp (talk) 06:13, 31 July 2016 (UTC)

Would you be interested in passing on this feedback Eric Scerri? Sandbh (talk) 12:54, 31 July 2016 (UTC)

Perhaps it would be better if you wrote it, because I would find it difficult to describe the mockery of a Sc/Y/La/Ac table posted there as anything more polite than "stupid". I would greatly prefer it if this task force did not try to make Sc/Y/Lu/Lr win by such lame arguments as atomic number triads (*), or by comparing it against straw men, but instead tried to do something like your previous excellent work at examining the evidence on both sides, having made clear what those sides actually are.

(*) I still stand by atomic number triads being a lame argument. It would seem to recommend a placement of H on top of F at the head of the halogens, when we know perfectly well that its chemistry is predominantly cationic (H⁺ being the foundation of acid-base chemistry, while H⁻ being a readily deformable species), and therefore that a placement of H over Li accords better with the chemistry of H. It is not for nothing that hydrogen chemistry is often called the chemistry of the proton. Besides, if you argue that Y/La/Ac does not form a perfect triad while Y/Lu/Lr does, where are we with Sr/Ba/Ra vs. the silly Sr/Yb/No? Not every group of three elements in a column will form a perfect triad. (And if one argues that we should keep the blocks together; well, that does not disallow Sc/Y/La, since all of them have the ds² configuration, and in fact are more similar to the trend in Ca/Sr/Ba – as should be expected because the chemistry of Sc, Y, and La is much more like that of a main group than a transition group.) Double sharp (talk) 08:34, 4 August 2016 (UTC)

Thank you for the kind words. Will you be OK if I bring the above thread to his attention? Sandbh (talk) 12:47, 4 August 2016 (UTC)

Yes, I think that would be OK. I ought to make it clear that I fully support the aims of the task force, because the confusion over the composition of group 3 has gone on for far too long without a resolution. With that in mind, I think that it should be looking only at forms of the periodic table that people actually use. Double sharp (talk) 13:02, 4 August 2016 (UTC)

I genuinely share a desire for a fair process since it's probably going to eventually be a big deal. I genuinely don't like the choice as it is presented, with an important alternative substituted for something none would support. I, however, don't think triads---that is, if I understand "triads" correctly: elements in the d-block, periods 5 through 7---are lame: elements in these triads are known to be very similar across early TM groups: Hf/Zr/Rf, Nb/Ta/Db, etc. And the argument that Y/Lu/Lr forms a good triad is a valid one, since group 3 is a d-block group. Comparison with group 2 is not correct, as elements from groups 4, 5, etc. have a full f-shell. Not the case of group 2. (I just came here for the sake of fairness; I'm not going to argue for either solution, at least for now.)--R8R (talk) 17:39, 4 August 2016 (UTC)

No, the triad argument I was presenting is not the one about properties, which I agree is not lame at all. It is that in the case of Z for Y, Lu, and Lr, 71 is the average of 39 and 103, whereas for Y, La, and Ac, 57 is not the average of 39 and 89. This, I think, is a bit lame, because it is not clear what this has to mean for the chemistry. Indeed an argument based on these triads for H puts it at the top of the halogens, where it looks very uncomfortable! Double sharp (talk) 23:46, 4 August 2016 (UTC)

P.S. Rf and Db show significant differences from Hf and Ta, like Lr does from Lu. OTOH, Fr, Ra, and Ac all show about-faces in the trends of physical properties going down their groups, so this is not a very conclusive argument. Double sharp (talk) 10:24, 5 August 2016 (UTC)

I see. By itself it means nothing, right. (And I'll skip a discussion on what follows from that today if you don't mind.)--R8R (talk) 11:55, 5 August 2016 (UTC)

P.S. "Rf and Db show significant differences from Hf and Ta, like Lr does from Lu. OTOH, Fr, Ra, and Ac all show about-faces in the trends of physical properties going down their groups" is a valid argument of its own, isn't it. I, however, still regard the group 3 debate as not purely scientific, but also dependent on context, so I'll just observe what the IUPAC does on the matter. Besides, the arguments have been said over and over. You just have to decide what you want to emphasize.

It would be strong if it continued in the d-block with Sg, Bh, and Hs, but it doesn't; these three are similar to their lighter homologues W, Re, and Os. W to Sg even shows an about-face in some of the trends involving complex formation; furthermore, Os to Hs also shows one in tetroxide volatility. So I think this is not actually that strong an argument.

I always thought of the group 3 debate as simply a matter of which classification is more generally useful, since no one disputes that Y has similarities to both La and Lu (although in the latter case, it is more of a general similarity to all the late lanthanides from Gd onward due to its size, rather than specifically Lu; whereas in La's case, neither of the neighbouring elements are similar to Y, while La is). The choice is then which relationship to display as primary, like magnesium to calcium, and which not to display as secondary, like magnesium to zinc. No one is disputing the truth of both, but one must take precedence. Since this is also similarly a size issue, and one of the most important trends in the table is increasing size as one travels further down the groups, I similarly favour lanthanum under yttrium as it conforms to this trend, explaining the similarity of yttrium to lutetium (and, even more so, holmium, which nobody suggests to put under Y) by means of the lanthanide contraction, just like how the d-block contraction makes Zn more similar to Mg. This favours an s-block-like trend over a d-block-like trend down group 3, but this is justified since the generally high reactivity and limited coordination chemistry of the rare earths is quite similar to those of the alkaline earths and is significantly different from that of the transition metals proper. (Besides, group 11 does not show a trend similar to that of groups 4 to 10, so the argument that group 3 must conform too is somewhat weakened.) Double sharp (talk) 14:35, 5 August 2016 (UTC)

Lanthanides and actinides as main group elements

P.S. Even in 1995, R. Bruce King's Inorganic Chemistry of Main Group Elements includes H, groups 1-3, the lanthanides and actinides, and groups 12-18. Double sharp (talk) 05:26, 15 August 2016 (UTC)

Curious. Does he say why the Ln and and An are counted as main group elements? That seems like a step too far. Sandbh (talk) 06:59, 15 August 2016 (UTC)

He explicitly says in the preface that "the main group elements...are defined here to include all the elements except for the d-block transition metals", and further goes on to talk about Sc, Y, Zn, Cd, and Hg as well in groups 3 and 12. Regarding the lanthanides, he writes "[since] the f orbitals are relatively uninvolved in chemical bonding, lanthanide chemistry is predominantly the chemistry of highly electropositive metals in the +3 oxidation state, just as the chemistry of the alkali metals and the alkaline earth metals is the chemistry of highly electropositive metals in the +1 and +2 oxidation states, respectively.... In fact, in many respects the trivalent Ln³⁺ ions...functions like a trivalent version of the heavier alkaline earths, namely strontium and barium." He also writes earlier that "The divalent lanthanide ions, namely Eu²⁺, Sm²⁺, and Yb²⁺...resemble Sr²⁺ and Ba²⁺ except for the ease of oxidation to the trivalent state."

I actually do sympathise significantly with the inclusion of the lanthanides. I would question the inclusion of the actinides, on the other hand, and even he admits that that is questionable "since, in contrast to the lanthanides, the actinide f orbitals plays a significant role in actinide covalent bonding." His excuse is that "comparison of the chemistry of lanthanides and actinides is instructive", which I think is a fair point, even if I think it should have been limited to a brief aside on how the actinides do not act like the lanthanides after Ac until we reach Cm.

He also writes "The chemistry of thorium is largely the chemistry of a single diamagnetic oxidation state with a noble gas configuration, namely +4, like many group elements such as aluminum. The chemistry of uranium is considerably more complicated than that of thorium, but uranium(VI) with the noble gas configuration and uranium(IV), two oxidation units lower, are the two most important oxidation states as in many main group elements such as tin, lead, antimony, and bismuth." I must say that I am not completely convinced, because this argument for Th would seem to work as well for Zr and Hf; additionally, the coordination chemistry of the early actinides is much more like that of the transition metals. (Also, U³⁺ is accessible, if very reducing. I can't argue with his supporting statement that UO⁺
₂ is very susceptible to dissociation to U⁴⁺ and UO²⁺
₂ in aqueous solution.) I understand that if we count by numbers and turn a blind eye to radioactivity, more of the actinides act like main group metals (Ac, Th, Pa, Cm, Bk, Cf, Es, Fm, Md, No, Lr) than like transition metals (U, Np, Pu, Am). However, when we look at those that are actually available in the average lab, it is rather inconclusive with Th acting like a main-group element and U like a transition metal. He also makes an argument regarding organometallic chemistry, which comes from the high electropositivity that characterises the left end of the periodic table: "almost all [the] organometallic compounds [of the lanthanides and actinides] are highly sensitive to air and water, like organometallic compounds of the alkali and alkaline earth metals but unlike many air- and water-stable organometallic derivatives of the d-block transition metals." Double sharp (talk) 08:06, 15 August 2016 (UTC)

P.S. He also has an interesting terminology of hyperelectronic and hypoelectronic elements, the former having "more than four valence electrons for a four-orbital sp³ manifold", the latter not. He seems to be referring mostly to the right side of the transition metals instead of the electropositive left side, so that the former would be the elements of groups 15–18 and the latter groups 12–13, with group 14 as an intermediary. He sees an "ionic divide" at group 18; a "covalent divide" at group 14; a "composite divide" at group 11; a "transition metal divide" at group 6; and an essential change in character between groups 3 (+ Ln and An) and 4 in his preface. In keeping with this, the order in which he discusses the groups is hydrogen; 14; 15; 16; 17; 18; 13; 1; 2; 12; 3, including Ln and An. Double sharp (talk) 08:45, 15 August 2016 (UTC)

P.P.S. ...and despite the 1995 date, his periodic table picture shows nothing beyond lawrencium, element 103, which closes off the actinide series. (Actually, I daresay that that is where the periodic table would end for an average chemist, for whom the last useable element is uranium, and the remaining actinides are only included so that we see a complete row to parallel the lanthanides. In fact, I distinctly remember seeing a simple introduction to chemistry at a bookstore just a decade ago, whose periodic table stopped at uranium...) Double sharp (talk) 13:07, 15 August 2016 (UTC)

P.P.P.S. Can't believe I forgot to mention it, but his periodic table (p.xx) is 14CeTh (Sc/Y/La/Ac), though he explicitly says that La is a lanthanide and Ac is an actinide. For him, the transition metals span only groups 4-11. Being written in 1995, the heaviest element then known was Rg, and his periodic table ends at Lr; so he need not consider Cn possibly acting funky, or the one minute exception of HgF₄, which has about as much relevance to Hg chemistry as does CoF⁺
₄ to Co chemistry, being known only as an unstable cation, kept in isolation from any other species, away from a normal chemical environment. Double sharp (talk) 05:48, 17 August 2016 (UTC)

8 elements with no category listed

Mt, Ds, Rg, Nh, Mc, Lv, Ts, and Og appear to not be marked at all in the table. Mt, Ds, and Rg are clearly transition metals, Nh, Mc, and Lv are post-transition metals, Ts is a halogen, and Og is a noble gas. Why aren't they marked as such in the table listed? 108.66.234.9 (talk) 14:04, 3 November 2016 (UTC)

Because there is a difference between empirically known properties and predicted ones, and the chemistry of these elements has not yet been investigated (there are plans to investigate them in the future). If you paid attention to that distinction you might actually learn something. You might even stop putting up unreliable sources on Talk:Extended periodic table and actually gain enough necessary competence to actually be a help and not a hindrance. Double sharp (talk) 14:11, 3 November 2016 (UTC)

P.S. They are not yet Nh, Mc, Ts, and Og. Would it kill us all to wait a few more days for IUPAC approval of those names? Double sharp (talk) 14:13, 3 November 2016 (UTC)

There are? Can you give me a link?--R8R (talk) 17:24, 3 November 2016 (UTC)

10.1021/cr3002438 Double sharp (talk) 02:41, 4 November 2016 (UTC)

In the same terrain, did you seen this article on relativistic effects "breaking" periodicity 10.1021/jacs.5b11793} ? Sandbh (talk) 03:14, 4 November 2016 (UTC)

Yes, although I am not particularly surprised given that this is simply a "super" inert pair effect that goes beyond the one you already see down near the bottom of groups 12 through 18. BTW, Cr₂ is not sextuply-bonded either. Double sharp (talk) 04:36, 4 November 2016 (UTC)

New names for elements

Nihonium and symbol Nh, for the element 113, Moscovium and symbol Mc, for the element 115, Tennessine and symbol Ts, for the element 117, and Oganesson and symbol Og, for the element 118. https://iupac.org/iupac-is-naming-the-four-new-elements-nihonium-moscovium-tennessine-and-oganesson/ — Preceding unsigned comment added by 195.3.129.182 (talk) 07:38, 9 November 2016 (UTC)

The IUPAC said (in the cited article) "A five-month public review is now set, expiring 8 November 2016, prior to the formal approval by the IUPAC Council." So now the 5 months is over, and it is time for the IUPAC to evaluate the public comments they have received. When they have done that, they will announce it, and when they do, WP editors will have a fair amount of work to do. But not just yet. YBG (talk) 07:58, 9 November 2016 (UTC)

I can well understand why the wait is just a little longer than those who read "8 November" might have accepted. If they had put up a press release, it would have been swamped by all the US election coverage. Double sharp (talk) 08:14, 9 November 2016 (UTC)

Group 3 RfC

An RfC on the composition of group 3 is still open at Template talk:Periodic table#RFC: Should this table follow the IUPAC version for lanthanides, and actinides?. -DePiep (talk) 05:41, 17 November 2016 (UTC)

Group 3 options do not create a different structure as Janet does

Currently, by TOC, the article has these sections:

5 Different periodic tables
   5.1 Group 3 constitution variants
   5.2 Periodic tables by different structure
6 Open questions and controversies
   ...
   6.4 Placement of hydrogen and helium
   6.5 Groups included in the transition metals
   6.6 Period 6 and 7 elements in group 3
   6.7 Optimal form

I think that the linked sections § 5.1 and § 6.6 are overlapping, redundant even. In short: 5.1 does not create a different periodic table structure. It is just one of the open questions, as is "§ 6.4 Placement of hydrogen and helium". OTOH, Janet's Left Step periodic table has a different structure (periodic rows by n + 𝓁 not classically by n).

We could simply remove § 5.1 and upgrade § 5.2 into 5 (into its == level section). Group 3-issues can be and should be described in § 6.6. Since the multiple group 3 options require as many different graphs, when required that could be explained in the graph section (presentation form). -DePiep (talk) 10:33, 29 November 2016 (UTC)

^ http://iupac.org/iupac-is-naming-the-four-new-elements-nihonium-moscovium-tennessine-and-oganesson/

[1] ttp://iupac.org/iupac-is-naming-the-four-new-elements-nihonium-moscovium-tennessine-and-oganesson/

[1]