Talk:Transition metal/Archive 1

four periods
I'm concerned at one change I have made. Previous text (emphasis mine):

This name comes from their position in the periodic table of elements, which represent the successive addition of electrons to the d atomic orbitals of the atoms as one progresses through each of the three periods.

My version (again, emphasis added):

''The name transition comes from their position in the periodic table of elements. In each of the four periods in which they occur, these elements represent the successive addition of electrons to the d atomic orbitals of the atoms.''

I'm not sure what was meant by three periods. Did it mean the three following periods, making four in all? Or was it just a mistake, and if so why am I the first to notice it? Or is there something I have misunderstood? Andrewa 20:35, 26 Jan 2005 (UTC)


 * This has now been explained to me. Four is the correct number (whew), the probable reason for the earlier version saying three is that all transition elements in the fourth period in which transition elements occur are radioactive, with all their isotopes having sufficiently short half-lives that exploring their chemistry is a bit problematic, my informant actually said most do not have any substantial chemistry but I suspect some of my old AAEC collegues would disagree here, they regarded positronium as having substantial chemistry and were exploring it on the big (to us) Van de Graaff.


 * The upshot is, while there were traditionally three periods of transition metals, now four are recognised... and there seems to be a consensus on that much, anyway. Andrewa 19:12, 17 July 2005 (UTC)

table of elements
I recommend that the table showing the transition metals be rearranged into horizontal periods and vertical groups like they would appear on the periodic table. I don't have enough wiki experience to try it for myself to see how it would look. If there is a good reason why the table is like this, I would at least like to know why. 164.58.8.58 17:42, 1 Mar 2005 (UTC)
 * No idea why the original author put it there, but it seems to me that a flipped table would squeeze out most of the running text. YMMV. --Christopher Thomas 19:43, 16 May 2005 (UTC)

Yes, the flipped table is too wide to run on the right side, but seems short enough to give its own space to. So I've changed:



to:

Please leave a message on my talk page if you want any additional formatting changes. -- Rachel 20:42, 15 August 2005 (UTC)

why there is only 8 groups in periodic table and not more?
I want to know why the outermost shell of atom only have at most 8 electrons?But the previous shell can have 18,32...? why a new shell is always started after 8 electrons? what is the difference between ion and atom?
 * Because a new shell is always started after 8 electrons even if there is room for more electrons to go in; the partly filled shell is completed later. (note this is only true for atoms, not ions) Physchim62 (talk) 15:03, 19 November 2005 (UTC)
 * Because, for an atom (not for an ion), the nd sub-shell is higher in energy than the (n+1)s sub-shell. Physchim62 (talk) 08:02, 20 November 2005 (UTC)
 * An atom has the same number of electrons as protons, and so has no electrical charge. An ion has more or fewer electons than protons, and so has an electrical charge. The energies of the different shells depends on the number of protons and on the number of electrons&mdash;the enrgies are different for each element, but the order is roughly the same. Physchim62 (talk) 08:12, 20 November 2005 (UTC)

Definition (again), zinc, scandium and now cadmium
See Wikipedia talk:WikiProject Chemistry. Andrewa 08:50, 4 February 2006 (UTC)

inconsistency
There seems to be an inconsistency in this article: Not all d'' block elements are transition metals. Scandium and zinc don't qualify...'', yet both scandium and zinc are listed in the table at the top of the article, and shown as transition elements in the periodic table. Scandium is stated to be a transition element in its article, zinc is not so described in the text but is in the infobox. Possibly the definition is not agreed by all authorities, or has changed recently? Andrewa 22:07, 17 Sep 2004 (UTC)


 * Whatever the historical cause, it seems that there are now two commonly accepted definitions of transition element and transition liquids. Although I am not a chemist I have had a go at fixing the article. It may still not be entirely accurate, and is not perfectly phrased, but I am confident that it is both better phrased and more accurate than what I started out with. Andrewa 14:07, 26 Jan 2005 (UTC)


 * I corrected this to the best of my knowledge. From looking at books and on the web, I still think 99% of all chemists consider scandium to be a transition metal.  Hence, I referenced the IUPAC definition, which would discludes cadmium.  I also did some general cleanup; the article still, however, clearly needs help.  Olin


 * The reason that some dont consider it a transition metal is because it actually fills up the 4s electron orbital rather than the 3d. Notice the exception for copper can chromium in the chart on Electron_configuration. All4One 19:32, 8 October 2006 (UTC)

From PNA/Chemistry

 * Transition metal - I raised some issues with this article on its talk page some months ago and got no response. I have now rewritten the introduction to be consistent with the usage of the term elsewhere in Wikipedia, notably in the periodic table and in the articles on the transition elements themselves. But I'm relying on high school chemistry, many years ago. In view of the technical nature of some of the material and the very significant changes I have made just to the introduction, I think the whole article needs a review by someone more knowledgable. I was going to list it for peer review but the function of that page is now linked to featured articles, and so now there doesn't seem to be better a place than this to request the old sort of peer review, which is what is needed. Andrewa 03:16, 27 Jan 2005 (UTC)

Shielding and Gold
While the article states: "The number of oxidation states of each ion increases up to Mn, after which they decrease. Later transition metals have a stronger attraction between protons and electrons (since there are more of each present), which then would require more energy to remove the electrons."

Would it not be more proper, this being a chemistry article and all, to invoke the concept of shielding, instead of beating around the bush.  Secondly, I was wondering should a discussion be done about golds aberrant yellow color. Which I have the understanding (from undergrad inorganic) is due to the 5d contraction as a result of relativistic mass coming into play. --PedroDaGr8 00:33, 22 April 2007 (UTC)

iron(V)
Iron in the picture is listed as having a common +5 oxidation state. I don't think that's right. I think it's absolutely extremely rare. Olin 19:32, 17 April 2007 (UTC)
 * The image is wrong in numerous other points as well. Someone give me a ping when I get back to France in a couple of days and I will get the data together for a corrected version. Physchim62 (talk) 21:25, 17 April 2007 (UTC)


 * I suggest using the figure from chapter 2 of Greenwood, which is more comprehensive as it also includes negative oxidation states. The current figure is unsourced, which makes me wonder who decided which oxidation states should be included as "common" and "less common". --Itub 12:05, 15 October 2007 (UTC)

Are noble metals also transition metals?
I saw the definition here to be: "More strictly, IUPAC defines a transition metal as an element whose atom has an incomplete d sub-shell". This is supposed to exclude zinc, cadmium and mercury and leave groups 3 to 11 in the definition. The noble metals (copper, silver and gold) however have also a filled d-shell (according to webelements.com). Why are they called transition metals as well then? Erwin 15:34, 3 September 2007 (UTC)


 * Because they easily form ions with incomplete d shells. --Itub (talk) 11:04, 21 November 2007 (UTC)

Are you serious?
Are you serious? You don't have a picture of a periodic table displaying which metals are the transition metals? I have to read to figure it out? How can you be serious? —Preceding unsigned comment added by 69.134.171.127 (talk) 02:00, 14 February 2008 (UTC)

Conductivity
It would be nice to get some general trend as to the conductivity of transition metals. Someone knowledgeable on this subject please add this into the main article. Thanks.  Gautam ''' Discuss 22:56, 15 May 2008 (UTC)

Regional spelling system
Following on from comments in the edit summaries regarding spelling. WP:ENGVAR has no preference for any spelling system but does require consistency throughout the article. This article has a mixture of British and American spellings. For cases where the subject is not identifiably either English or American ENGVAR says that the spelling should follow that of the first major contributor or the first contributor to make an edit that disambiguates the variety. The very first edit seems to be an import from Nupedia in 2001 with the edit summary spellinhg (sic). It is very short and has no words that disambiguate spelling other than the link to sulfur which is merely the name of the linked article. This is followed by a substantial series of edits by user:Sodium which is beyond doubt using the British spelling system. On that basis I would say the article should be standardised on British spelling. Does anyone else have any comments? Does anyone else care?  Sp in ni ng  Spark  02:09, 16 February 2009 (UTC)
 * I care! I care that we don't waste time arguing over it! Thanks for the research Spinningspark! There is a talk page template for this sort of question, British-English (and its various equivalents for other regional varieties): I won't hoist the Union Flag until others have had a chance to comment though. Physchim62 (talk) 08:52, 16 February 2009 (UTC)

Valence electrons
"Transition metals are metals with one or two valence electrons"-- should this be qualified with "typically", or otherwise expanded to account for Palladium? Tom239 (talk) 19:02, 8 March 2009 (UTC)
 * No, it needed to be deleted as patently untrue! The whole concept of "valence electrons" is a bit tricky for transition metals. Physchim62 (talk) 19:08, 8 March 2009 (UTC)

Groups A or B of periodic table? Both were correct.
Today user 67.165.30.215 changed the alternate labels of Groups 3-10 to read IIIB - VIIIB, and then user Shootbamboo reverted these labels to read IIIA - VIIIA. Actually as explained in Group (periodic table), both numberings are (or were) correct since the first is the old American system and the second is the old European system. The modern IUPAC numbering (Groups 1-18) was introduced in order to eliminate this confusion.

Since both the old numberings have been superseded by IUPAC, I think this article should mention either both or neither. I prefer neither - just number the transition metal groups from 3 to 12 (if Zn,Cd,Hg are included). Dirac66 (talk) 02:57, 13 May 2009 (UTC)
 * No strong preference here. -Shootbamboo (talk) 00:33, 14 May 2009 (UTC)
 * OK, thanks. I have opted for neither and retained only the modern IUPAC numbering (3-12), as in the intro paragraphs and in many other Wiki articles. Dirac66 (talk) 01:23, 14 May 2009 (UTC)

oxidation states of platinum
Platinum does have a +6 oxidation state, as in platinum hexafluoride, however, this isn't reflected in the table under "Variable oxidation states". Similarly, gold(V) fluoride also exists, showing that the post-group-8 trend in period 6 is higher than this table would indicate. Can someone update this table?&mdash;Tetracube (talk) 03:40, 25 June 2009 (UTC)


 * P.S. For that matter, platinum also has a +5 state, in (see the platinum hexafluoride article).&mdash;Tetracube (talk) 03:43, 25 June 2009 (UTC)

The +5 state is also found in the PtF6- anion, also mentioned in the PtF6 article. Dirac66 (talk) 22:17, 27 June 2009 (UTC)

Electronic structure exceptions
To Peter Gans: Your ongoing rewrite is in general very good. However the following sentence seems to be too general and ignore the exceptions:

The electronic structure of transition metal atoms can be written as ns2(n-1)dm, as the inner d orbital has more energy than the valence-shell s orbital. In compounds of the transition metals the situation is reversed so that the s electrons have higher energy.

I would suggest: The electronic structure of MANY transition metal atoms can be written as ns2(n-1)dm, as the inner d orbital has more energy than the valence-shell s orbital. In MOST IONS of the transition metals the situation is reversed so that the s electrons have higher energy.

Comments: MANY because Cr, Cu, Pd etc are exceptions. Pd in fact has no 5s electrons. IONS as for your examples. The orbital order in compounds is a much more complex subject; first of all the experimental results are for molecular orbitals which cannot always be identified with atomic orbitals. And MOST because there are exceptions too, especially the 1+ ions. Dirac66 (talk) 15:12, 25 August 2009 (UTC)
 * You are, of course, correct regarding exceptions for atomic orbitals. I also agree with your comment about orbitals in molecules. I think I has the divalent and trivalent ions in mind when I wrote that bit. With the lower and higher oxidation states covalency is much more important. I'll seek to clarify the text. Petergans (talk) 18:19, 25 August 2009 (UTC)

Sign posts on pages when not logged in
Why should you sign your posts?

How do you sign posts when not logged in? —Preceding unsigned comment added by Wd930 (talk • contribs) 01:29, 5 December 2010 (UTC)

You sign your posts since a record of a discussion should include information on who said what. To sign in without logging in, you could just sign manually by typing out your Wikiname.Dirac66 (talk) 03:56, 5 December 2010 (UTC)

Neutrality
I demoted the article from C-class to Start-class a while ago because of the fact that it mentioned the two alternative definitions of transition metal, only to dismiss one as "historical" although it is obviously still current, and not to discuss the other further. Lanthanum-138 (talk) 13:22, 7 May 2011 (UTC)
 * Perhaps the intro should not use the phrases "In the past" and "modern". I suggest the following changes in the intro to restore neutrality:

Dirac66 (talk) 15:32, 7 May 2011 (UTC)
 * 1) Change "In the past the term transition metal referred to any element ..." to "Some authors describe as a transition metal any element ..."
 * 2) Remove "modern" before "IUPAC" but place the IUPAC definition first.
 * Addressing these points. Lanthanum-138 (talk) 14:00, 12 May 2011 (UTC)
 * Done. Back up to C-class now. Lanthanum-138 (talk) 14:03, 12 May 2011 (UTC)
 * Ok, all is good now except for the reference to Jensen, who actually reviews both usages and several others dating back to 1920. I'll put that he has reviewed the history of the term. Dirac66 (talk) 14:22, 12 May 2011 (UTC)

Compounds
I would find it helpful if this article had a table giving for each transition metal the most common ions/oxidation states found in compounds. — Preceding unsigned comment added by Skysong263 (talk • contribs) 22:26, 19 December 2011 (UTC)

A user's comment
A user with IP address 207.160.218.253 put the following comment into the article itself. I removed it from the article, but it sounded well-meaning rather than intentional vandalism, so I'm copying it here. The comment said: "Transition metals change all the time. They just change from one metal to another. You can get a peice of gold and can get platinum or any of the transition metals. It has a cool rippleing effect." NOTE: I (user elysdir) know nothing at all about the topic nor about this particular comment, so please don't ask me about it. I'm simply moving another user's comment from the article body to the Talk page. --Elysdir 17:39, 30 November 2006 (UTC)


 * It was vandalism. Double sharp (talk) 07:53, 20 January 2012 (UTC)

The metals
So let's decide what metal should be considered transition. I think, groups 4-11 metals are unbeatably transition, so no more about them. I just don't understand why my version of 20 July 2010 was considered so wrong (no, it wasn't 100% right, I admit! But still better than that of today). 'Twas neutral; I've never heard Sc and Y to be not transition, so that's my dominant; but I recognize some may disagree so I mentioned it; Same thing on group 12 elements (but I guess I was some wrong there; only mercury is 100% transition since there's no a definition not allow it to be something else - read mercury(IV) fluoride; according to IUPAC, zinc and cadmium are not transition). Also, my words about group 3, periods both 6 and 7 were also ignored (where it was really neutral! I've spit on my own opinion these should be Lu and Lr, not La and Ac). Also, I guess, it should be mentioned that according to IUPAC, uranium is transition metal (along with thorium, cerium, curium, gadolinium, neptunium, protactinium (and elements of 3-11 groups plus mercury)), since their atoms have d electrons. Also, La, Ac and Lu also have d electrons but Lr doesn't, being (huh!) a main group element (or else but still not transition to IUPAC). Of course, it doesn't have to be article's base but at least should be mentioned.

But currently, instead, article names Sc and Y mostly considered not transition, not mentioning why they can be (I mentioned why they can be considered not transition). Lu and Lr aren't even mentioned at all, although they're at least same possible to be transition. And, what's worse, article says "Zinc, cadmium, and mercury are not transition metals." Mercury definitely is, as proven before. Zn and Cd may be, and may not be. I think saying "Zinc and cadmium can be counted as both transition and not transition, as they have no compounds with incomplete d shell but traditionally they can be counted transition. Mercury should be mostly considered transition but it was not known before 2007 that it can have incomplete d shell, so in some cases it is still counted not transition, and also in some cases can be as its two lighter homologues are not transition. Today, there is no definition which makes mercury not transition" or something like that. Hope, my words won't be missed--R8R Gtrs (talk) 17:38, 23 October 2010 (UTC)

Group 12
The debate over whether mercury should now be considered a transition metal is reviewed in the article on mercury(IV) fluoride. Since there are authoritative opinions on both sides of the question, I have changed the article to mention this controversy, as per Wikipedia NPOV policy, with a reference on each side.

For Cd and Zn no compounds have been prepared (to date) in oxidation states higher than II, so they are not considered as transition metals by the IUPAC definition.

I will think more about Group 3.Dirac66 (talk) 17:56, 24 October 2010 (UTC)

Group 3 and f-block
I have now revised the article concerning group 3 and the f-block. For Sc and Y every source I checked classifies them as transition metals, so I deleted the statement that they are not. For La-Lu and Ac-Lr I found three different opinions, so I have included all three. There seems to be no consensus on the classification of these elements. Dirac66 (talk) 23:57, 6 November 2010 (UTC)
 * states that neither Sc nor Zn are transition metals. It does not discuss the lanthanides and actinides. Double sharp (talk) 07:56, 20 January 2012 (UTC)

Not neutral, not logical, not complete
End of "Classification" section is biased against the Zn-Cd-Hg-are-not-transition-metals view. (And just what is the electron configuration of Hg+? If it has a full 6d shell, as I think it does IIRC, then the argument used is flawed in the first place.) Also, just because it is convenient to compare the Zn group to the transition metals doesn't mean that they are transition metals. Consider that the article also mentions Ca2+ along with Zn2+ as useful comparisons against transition metal ions; do we ever consider Ca a transition metal? And as for HgF4, it completely disregards Jensen's view that this is an exceptional compound and isn't characteristic of the element and so shouldn't determine the group (so calling the Zn group transition metals is like disregarding 99.999% of their chemistry in favour of 0.001% of it in a compound that is so unstable nobody will actually use it).

Yes, I'm currently high on Jensen ;-). But both views should be represented together, and the article should absolutely not call one of them "incorrect".

There's a related problem with logic in the Lu/Lr-are-group-3 paragraph. Just because La and Ac have exceptional s2f0d1 configurations doesn't make them d-block elements and doesn't make them transition elements. Thorium has electron configuration [Rn]6d27s2, yet no one calls it a transition metal. (Also, Lr's electron configuration isn't [Rn]5f146d17s2, it's [Rn]5f147s27p1, which makes any argument based on similar electron configurations rather weak here.) Double sharp (talk) 08:37, 3 August 2013 (UTC)

P.S. And the article never seems to mention the difference between d-block and transition metal even if you take the Lu/Lr-are-group-3-and-group-12-are-transition-metals-view; being in the d-block is an atomic property whose only requirement is that you have valence electrons in d-subshells, whereas being a transition metal is a chemical property whose requirement is that you show the typical chemistry of a transition metal. Hence, Mt, Ds, and Rg, not having shown any chemistry (it hasn't been tested yet), are not transition metals yet (until such time that experiments are carried out and they are found to behave as expected, of course). (Strictly speaking, since we don't know the electron configurations of anything above Rf, should we really label them in Block (periodic table) as being in the d- and p-blocks?) Double sharp (talk) 08:41, 3 August 2013 (UTC)

P.P.S. This is worse than I thought! At the beginning of the "Classification" section we have the statement that the d-subshell has higher energy than the s-subshell. Sloppy aufbau perhaps? They have about the same energy, and in fact the d-subshell is filled first: Sc has valence electron configuration 3d14s2; Sc+, 3d14s1; Sc2+, 3d14s0; Sc3+, 3d04s0. The additional electron in Sc2+ that Sc3+ does not have goes into 3d, not 4s!!! In fact they all enter 3d, but two get repelled into 4s (energetically worse for them but better for the entire scandium atom). No situation is reversed, as the article may tell you!!! (Also, in divalent and trivalent transition metal ions, there aren't any s electrons, so how can they have higher energy?) Pairs such as 4s/3d, 5s/4d etc. don't always have the first orbital with lower energy than the second, depending on what element you are talking about! (The same occurs for f-block elements, but that's not an issue for this page.) This would be a great article, if it would only explain things correctly... Double sharp (talk) 08:51, 3 August 2013 (UTC)
 * Elementary textbooks (and some editors) like the 3-12 definition because it is simple for students, but I agree with you that an encyclopedia article should be more neutral and nuanced. For now I have made the language a little more NPOV, removing the "incorrectly" for example. Also I noticed that the article incorrectly cited both Andrews and Jensen as saying that the synthesis of HgF4 shows that Hg is a TM; I checked the sources and this is Andrews' view but Jensen disagrees. Dirac66 (talk) 16:00, 5 August 2013 (UTC)

Assessment comment
Substituted at 09:11, 30 April 2016 (UTC)

Elements literally included by the IUPAC Gold Book definition

 * Fourth period: Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu
 * Fifth period: Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag
 * Sixth period: La, Ce, Gd, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg
 * Seventh period: Ac, Th, Pa, U, Np, Cm, Bk, Rf (the following elements do not have experimentally known electron configurations)

In particular, Lr ([Rn]5f147s27p1) cannot be considered a transition metal by this definition as it does not have an incomplete d-subshell, nor can it give rise to cations with such incomplete d-subshells. So if you wanted to follow IUPAC's definition here, the only possible choice for group 3 is for it to have scandium, yttrium, lanthanum, and actinium. Of course, one could argue that this is surely not the spirit of the definition. Double sharp (talk) 12:17, 8 July 2016 (UTC)

why on earth is the 4-11 definition given so much prominence
I should have thought it would be the least prominent! It appears to be mainly a UK thing and is the only one of the three most common ones (3-11, 3-12, 4-11) that is not allowed by IUPAC. IUPAC is flexible on group 12 but always says that either the element must have incomplete d-orbitals or it must form ions that do so. The first point forces group 3 in. Of course there are problems. If we take it literally, uranium is a transition metal but neodymium is not, and neither is lawrencium: probably not how most would define it. But there is no way to read this that excludes Sc and Y. Double sharp (talk) 03:40, 24 December 2015 (UTC)
 * (P.S. I'm trying not to be biased when I say this, because 4-11 is the definition I was taught.) Double sharp (talk) 06:08, 8 July 2016 (UTC)


 * I don't think the present article really intends to include a purely 4-11 definition. The paragraph to which I think you refer says The elements of groups 4-11 are generally recognized as transition metals, justified by their typical chemistry, i.e. a large range of complex ions in various oxidation states, coloured complexes, and catalytic properties either as the element or as ions (or both). The elements La–Lu and Ac–Lr and Group 12 attract different definitions from different authors. The phrase generally recognized means that everyone (or nearly everyone) includes the 4-11 elements, but that does not imply that anyone includes only the 4-11 elements. The next sentence means that there is disagreement about which of La-Lu, Ac-Lr and Group 12 should be included, as detailed in the following paragraphs.
 * The real confusion seems to be due to the fact that Sc and Y are not discussed properly here, but only briefly mentioned in one of the following paragraphs. But on reading the whole article, I think it is clear that Sc and Y are also included by (nearly) everyone. So I am going to explicitly mention Sc and Y as generally recognized in addition to groups 4-11. I hope this clarifies the article. Dirac66 (talk) 22:49, 10 July 2016 (UTC)

Greenwood and Earnshaw's properties of transition metals
To quote literally from page 905:

I would not take them too literally when it comes to the exclusion of the 6d metals, as they cover actinium together with the rest of group 3 (scandium, yttrium, and lanthanum) and they mention in the chapter on the actinides and transactinides that rutherfordium through copernicium form a fourth, 6d transition series (along, of course, with actinium).

Based on what they go on to cover, they appear to accept all members of group 3 to 12 as transition metals (Sc–Zn; Y–Cd; La, Hf–Hg; Ac, Rf–Cn). They have some more specific remarks on the borderline cases of group 3 and 12.

With regard to group 3, they specifically distance it from the "transition elements proper", while still not disputing their classification as such by (i), writing (p. 948):

The story is different for group 4, and thereafter remains different. Greenwood and Earnshaw do not refer very much to Hf because it is so similar to Zr. Now for p. 958!

Of course, the coordination chemistry is still a little different, as it is not helped very much by synergic &pi; bonding (too few d electrons). Although the MIV (M = Ti, Zr, Hf) ions are much smaller than the preceding MIII ions (M = Sc, Y, La), they are large enough to get to high coordination numbers like 8 for Zr and Hf, which is unusual for the transition metals. Additionally, Zr and Hf do not have aqueous chemistry in states below the maximum because these reduce water. But in general, the rich coordination chemistry of the heavier elements is enough for me to say that unlike Y and La, Zr and Hf are bona fide transition metals by fulfilling criterion (iii). The stories become normal from group 5 onward, where V is similar to Ti (although it prefers +4 to +5), and Nb and Ta anticipate the rich cluster compound chemistry of Mo and W. Already, +5 is much too high an oxidation state to allow any simple ionic salts, even for Nb and Ta.

A bit of weirdness starts to kick in again in group 11, the most ancient royal trio of copper, silver, and gold. They definitely fulfill (i), but only one valence electron is delocalised in their fcc lattice. Furthermore, if we look at the "are there partially-filled d-subshells" definition, silver stands out as its most common oxidation state is Ag+. The only aquo ions in here are Cu+ (not stable), Cu2+, Ag+, and Ag2+ (not stable). (Gold tends to occur as the form of square-planar [AuCl4]−, as the main route is dissolution of the metal in aqua regia.) Additionally, Cu+ and Ag+ complexes are of rather lower stability than those of Au3+, and the univalent coinage metals show coordination number 2 which is unusual in "transition metals proper (i.e. excluding Zn, Cd, and Hg)" (that word again!). Nevertheless, AgII is common enough that these elements should be considered transition metals.

Last of all is group 12, which never breaches the d subshell under standard conditions (HgF4 doesn't count). Yet there are still some points in their favour, mostly because of (iii): a quote from p. 1206 follows.

Hence, we can see that the transition elements may be taken to occupy groups 3–12, with groups 3–4 on the left side and 11–12 on the right side forming preludes and postludes connecting them to the main group. The lanthanides and actinides, coming between groups 3 and 4, similarly form part of this rising of the curtain for the main star of the show, the behaviour we all know and love from, most especially, iron. Double sharp (talk) 12:53, 4 August 2016 (UTC)
 * Very interesting summary of the views of Greenwood and Earnshaw, who have certainly written one of the leading current textbooks. Next question: what specific changes would you propose to the classification of elements in this Wikipedia article? Dirac66 (talk) 19:31, 6 August 2016 (UTC)
 * Firstly, we start only by a cold definition of what elements qualify to be considered as transition metals in the lede. We should also do something like what Greenwood and Earnshaw did by talking about some characteristic physical and chemical properties that are common to the vast majority of them. I realise we have this later but this should honestly be in the lede!
 * Then we can talk about, in the next section, what elements are generally considered under this term, and talk about how there are some borderline cases. Groups 3, 11, and 12 have had a history of not being included, and even group 4 shows some differences. The inclusion of the transactinides also needs a few caveats since the chemistry of Mt, Ds, and Rg has not yet been studied, and even for Ac as well as Lr–Cn it is still poorly known compared with the stable elements (plus Tc) in the first three rows. Additionally the group 3 issue spills over somewhat into here, depending on whether you consider La, Lu, or neither to be a transition metal, and whether this disqualifies them from being considered lanthanides.
 * I would also like to have descriptive physical and chemical profiles for each of the elements that is normally included, like what we have at post-transition metal (this will overlap for groups 11 and 12). This would be rather long and would have group-by-group summaries. We can skip sections such as history, production, and biological roles, since it is difficult to find a common thread running through all thirty-one of these elements that I usually think about when I hear "transition metal" (Sc, Y, La, Ac; Ti, Zr, Hf; V, Nb, Ta; Cr, Mo, W; Mn, Tc, Re; Fe, Ru, Os; Co, Rh, Ir; Ni, Pd, Pt; Cu, Ag, Au; Zn, Cd, Hg – I think of Rf–Cn predominantly as transactinides rather than transition metals). Anyway Fe dominates the whole block in these fields. (I think we can discuss the lanthanides and actinides all together in one single paragraph, raising arguments for their inclusion and exclusion, and looking at the specific cases of La and Lu, respectively Ac and Lr, at the front and back ends of the series.)
 * P.S. I think that all the group articles do not need to go into very much detail on sections such as history, production, and biological role. Look at the triad of Fe, Ru, and Os, for instance: Fe utterly dominates the others in these sections, and the only plausible reason to talk about all three together is their scientific properties. Cu, Ag, and Au are the only case when history makes sense to include together, but even then only Cu among this triad has a biological role. Even in alkali metal (which I mostly rewrote), the chemistry sections tend to nicely talk about the whole group (obviously, Fr excepted), while the later sections tend to be split neatly into paragraphs describing each element separately, since Li for example does not generally occur together with Na and K, but rather with Mg due to its similar size. Double sharp (talk) 06:10, 7 August 2016 (UTC)
 * Two comments:
 * The problem with starting with a cold definition of what elements qualify is to decide whose cold definition to use. There are several out there and Wikipedia is supposed to remain neutral in controversies - see WP:NPOV. If we want a single statement for the lede, it would have to be broad enough to include all the points of view. Perhaps we could say at the outset that there are various definitions which include all or some of Groups 3-12 plus the rare earths (or f-block). Then of course the Classification section can include the various schools of thought, including Greenwood and Earnshaw. Dirac66, 9 August 2016
 * I think you may have misunderstood what I was trying to say, so I'll try to rephrase it. Currently we do start with three cold definitions, which is good. I also like your idea of saying that all of the elements Sc–Zn, Y–Cd, La–Hg, and Ac–Cn have had the term applied to them. But we should IMHO also add some properties that these elements also share – a sort of justification for the definitions, if you will. After all, alkali metal says in its lede "The alkali metals are all shiny, soft, highly reactive metals at standard temperature and pressure and readily lose their outermost electron to form cations with charge +1." Can we not have something similar to describe the TMs? Double sharp (talk) 05:56, 30 August 2016 (UTC)
 * Yes, I will agree that it would be a good idea to also add a statement of the common properties of all (or most) transition metals. Dirac66 (talk) 13:44, 30 August 2016 (UTC)
 * I agree that we do not need to discuss the history, production and biological role of all the elements, which belong in the articles on each element. We should however retain the brief paragraph now at the end of the lede about Charles Bury, which belongs here because it pertains to all the transition metals. Dirac66, 9 August 2016
 * Agreed. There is no sense in talking about individual elements' history, production, and biological roles here, but anything relating to all of them is fair game. Double sharp (talk) 06:01, 30 August 2016 (UTC)

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

The RfC can be found here. Sandbh (talk) 23:12, 9 August 2017 (UTC)

is ion stable?
are ions sable since they have gained or lost electrons?


 * Please sign your posts on talk pages, even if not logged in. Andrewa 08:50, 4 February 2006 (UTC)
 * some are some arent. Porygon-Z 15:35, 3 December 2018 (UTC)

Mt, Ds, and Rg
They aren't classified as primarily Transition metal in the article, so why is it unknown if Hs is a transition metal and Cn is a post transition metal? Porygon-Z 15:55, 3 December 2018 (UTC)
 * Because, as I told you at Talk:Copernicium, experiments probing the chemistry of Mt, Ds, and Rg have not yet been done, but experiments probing the chemistry of Hs and Cn have (and they have led to rather clear conclusions, unlike those that have been done for Nh and Fl so far). As this article says: "Although meitnerium, darmstadtium, and roentgenium are within the d-block and are expected to behave as transition metals analogous to their lighter congeners iridium, platinum, and gold, this has not yet been experimentally confirmed." Double sharp (talk) 04:39, 5 December 2018 (UTC)
 * But it's odd that it goes from Hassium to Copernicium. Shouldn't it go in order? Porygon-Z 12:52, 5 December 2018 (UTC)

Move discussion in progress
There is a move discussion in progress on Talk:Alkali metal which affects this page. Please participate on that page and not in this talk page section. Thank you. —RMCD bot 06:14, 28 February 2019 (UTC)

Orphaned references in Transition metal
I check pages listed in Category:Pages with incorrect ref formatting to try to fix reference errors. One of the things I do is look for content for orphaned references in wikilinked articles. I have found content for some of Transition metal's orphans, the problem is that I found more than one version. I can't determine which (if any) is correct for this article, so I am asking for a sentient editor to look it over and copy the correct ref content into this article.

Reference named "Miessler": From HSAB theory: Miessler G.L. and Tarr D.A. "Inorganic Chemistry" 2nd ed. Prentice-Hall 1999, p.181-5 From Hydrogen:  From VSEPR theory:  

I apologize if any of the above are effectively identical; I am just a simple computer program, so I can't determine whether minor differences are significant or not. AnomieBOT ⚡ 01:28, 10 September 2020 (UTC)


 * Fixed. Dirac66 (talk) 02:22, 10 September 2020 (UTC)

Problems with the chart of oxidation states
This chart showing oxidation states of transition metals looks really nice:

https://commons.wikimedia.org/wiki/File:Transition_metal_oxidation_states.svg

but the chemist Matt Cliff tweeted:


 * "This chart is a little odd: Ru(II) and Ru(III) are the most common oxidation states in its coordination chemistry, and whether some of the rarer states are included or not is a bit strange."

I checked, and indeed Ru(II) and Ru(III) are common oxidation states not shown in the chart. So someone should fix this chart!


 * Update this has been edited now, thanks to John Baez for pointing the missing states and to Andel for fixing them. Dabed (talk) 17:52, 19 February 2022 (UTC)