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Some of the superheavies might reach that too – Rf appears to be [Rf(H2O)84+ (10.1016/j.nuclphysa.2015.07.013). Admittedly chemistry beyond Lr is quite recent and sketchy. Double sharp ( talk) 16:08, 8 April 2017 (UTC)
FWIW, discussion below has led to the conclusion that we shouldn't discuss superheavies in this article. There we have only theory in the absence of experimentally clear confirmation (or in one case, Rf, just supposition based on similarity of the observed behaviour to the lighter homologue Hf). Also the predictions are very patchy, and calculations become pretty difficult because of need to take into account relativity, and the whole subject seems to be veering off from the focus of the article. Basically, it is a similar case to astatine. This sort of thing is probably better discussed in the individual element articles as almost totally predicted chemistry and indirect evidence. Double sharp ( talk) 07:35, 16 December 2020 (UTC)
I have copied the discussion (below) here to open it up to a wider audience. The issue concerns the placement of Al in the list of metallic elements, shown in a partial long-form periodic table. I proposed the unconventional layout shown below as being more suitable for the subject matter of the article. Both the traditional and proposed layouts have advantages and disadvantages. The layout chosen depends in which criteria are regarded as being more important. What is undeniable is that the atomic number of Al is one more than that of Mg, which is a good reason for placing these elements next to each other. The discussion is opened out to see if a consensus can be reached.
The issue is: which layout should be used in this article for the table of metallic elements. Petergans ( talk) 10:57, 18 May 2018 (UTC)
Li | Be | ||||||||||||||||||||||||||||||
Na | Mg | Al | |||||||||||||||||||||||||||||
K | Ca | Sc | Ti | V | Cr | Mn | Fe | Co | Ni | Cu | Zn | Ga | Ge | ||||||||||||||||||
Rb | Sr | Y | Zr | Nb | Mo | Tc | Ru | Rh | Pd | Ag | Cd | In | Sn | Sb | |||||||||||||||||
Cs | Ba | La | Ce | Pr | Nd | Pm | Sm | Eu | Gd | Tb | Dy | Ho | Er | Tm | Yb | Lu | Hf | Ta | W | Re | Os | Ir | Pt | Au | Hg | Tl | Pb | Bi | Po | At | |
Fr | Ra | Ac | Th | Pa | U | Np | Pu | Am | Cm | Bk | Cf | Es | Fm | Md | No | Lr | Rf | Db | Sg | Bh | Hs | Mt | Ds | Rg | Cn | Nh | Fl | Mc | Lv | Ts | Og |
(Copied from User talk:Double sharp|talk)
I placed Al in group 3 because, in this context of ions in solution it makes more sense. This is not the normal layout convention, but then, neither is the long-form periodic table. Further, there is an explanation in the article, copied below, as to why Al may be considered together with Sc rather than with Ga in terms of periodicity.
I won't undo your edit; please do so if you can accept the motivation for putting Al in group 3 rather than in group 13. Petergans ( talk) 09:13, 15 May 2018 (UTC)
@ Petergans: I again do not think the new layout [1] is an improvement. Firstly, all of these groupings of elements are already apparent on a normal periodic table. Secondly, the transactinides are omitted despite there having already been some aqueous chemistry done on Rf, Db, Sg, and Hs. Thirdly, I remain unconvinced that the changes are actually going to help understanding. For example, if we are going to duplicate La and Ac, then why not Y which behaves like a heavy lanthanide? And again, putting Al on top of Sc neglects the greater similarity of the structure and solvation of the Al3+ cation to the Ga3+, In3+, and Tl3+ cations rather than to the Sc3+, Y3+, and La3+ cations. I completely disagree that Al having an atomic number one more than Mg is a good reason to put them next to each other; otherwise one could use the same reasoning to put Ti and Zr over Ce, as I have previously noted. Pending further discussion I have restored the previous standard 18-column layout, which seems to have remained mostly constant for almost seven years since June 2011 when an IP editor moved Al to its usual position above Ga.
Perhaps we might find a larger audience for this discussion at WT:CHEM? Double sharp ( talk) 15:34, 20 May 2018 (UTC)
Petergans has changed the periodic table picture shown back to his preferred layout; I have moved Al back to being on top of Ga (this time more consistently), because I'm still not convinced that moving it to above Sc is more useful in this context – not the least because the 6-coordinate structure of Al3+ is similar to that of Ga3+ and In3+, but not that of Sc3+ and Y3+. Even papers specifically focused on the topic of metal ions in aqueous solution do not make this change (e.g. 10.1351/PAC-CON-09-10-22). Double sharp ( talk) 12:12, 24 October 2018 (UTC)
It is a fact that the atomic number of Al is one more than the atomic number of Mg. In the present context, it makes sense for these two elements to be shown next to each other and for Al to be above Sc. If this was a periodic table, I would accept the conventional layout, but it is not; the elements in the top right corner are missing from this table as they are not metallic. Petergans ( talk) 13:01, 24 October 2018 (UTC)
I see that labels of static vs dynamic are used in connection to the methods of determination. I think that a more explanation is required for these qualifiers. Perhaps dynamic is intended as a synonym for kinetic or transport properties, from what it can be noticed.-- 5.2.200.163 ( talk) 14:07, 20 June 2018 (UTC)
I think that the article should mention the explicit expression of the hydration number as a function of radial distribution function, which I see mentioned in the article.-- 5.2.200.163 ( talk) 14:23, 20 June 2018 (UTC)
I think it would be necessary to add details about the determination procedure of the residence time of solvent in the first solvation shell.-- 109.166.139.84 ( talk) 21:59, 24 October 2019 (UTC)
The newly added book inserted as Further reading seems to contain such info.-- 109.166.139.84 ( talk) 00:32, 25 October 2019 (UTC)
I see there are some specs re water exchange kinetics, which deserve some questions/clarifications. How is the aqua ion concentration determined?-- 109.166.139.12 ( talk) 21:53, 18 November 2019 (UTC)
Also how is the constant k determined as first-order rate constant? By using a graph concentration of aqua ion [A] vs time, [A](t) which is supposed to be (approximately) a linear function?-- 109.166.139.12 ( talk) 22:09, 18 November 2019 (UTC)
There is another aspect needing clarification, two inconsistent statements about the dimension of rate constant k:
"The unit of the rate constant for water exchange is usually taken as mol dm−3s−1. The half-life for this reaction is equal to loge2 / k. This measure is useful because it is independent of concentration. It has the dimension of time. The quantity 1/k, equal to the half life divided by 0.6932, is known as the residence time or time constant."
-- 109.166.139.12 ( talk) 22:42, 18 November 2019 (UTC)
The inconsistency is between the dimension amount (of substance)/(volume*time) of k and the dimension time for 1/k.-- 109.166.139.12 ( talk) 23:00, 18 November 2019 (UTC)
In the first sentence "rate constant" should be replaced with "reaction rate".-- 109.166.139.12 ( talk) 00:53, 19 November 2019 (UTC)
I see in the article some statement re the determination of hydration number of metal ions by using ion transport number. Some more details are needed.-- 109.166.139.12 ( talk) 21:11, 19 November 2019 (UTC)
If this were a periodic table, I would agree with you, but it is not: it is a table showing which elements are metallic, as its title specified. In this context, placing Al, on its own, above Ga looks odd, and there is nothing in the article text to explain why it is there. At User:Petergans/sandbox I have toyed with the idea of using a standard layout and colouring the non-metallic elements red, but everything I tried was unsatisfactory in one way or another. Petergans ( talk) 11:37, 14 December 2020 (UTC)
@ Petergans: Do you think we should go a little bit further about what happens for these metals? Currently we have just a short uncited remark. My understanding is that in some cases (e.g. W) simple aqua cations are hard to find, even though of course W is chemically clearly a metal, because of tendencies towards cluster formation in the lower oxidation state where cations are likely. FWIW the Persson paper on structures ( doi: 10.1351/PAC-CON-09-10-22) lists Nb, Tc, Ta, W, and Re as lacking aqueous cationic chemistry (for Nb and Ta, I guess it is because to a first approximation these metals have only the +5 oxidation state as the usual one). Unfortunately, I haven't found theoretical studies for this region like I have for the ones near the metal-nonmetal dividing line. Double sharp ( talk) 07:31, 16 December 2020 (UTC)
Surely there should be a section on lanthanides and actinides? Conjecture should be avoided, so perhaps the heavier actinides might be omitted from the table of elements that form metal ions. Petergans ( talk) 21:32, 3 February 2021 (UTC)
The table has been re-organised to long form; this removes possible controversy over the position of lutetium etc.. Early transition metals in rows 2 and 3 are marked as not forming aqua-ions.
Do germanium, arsenic, antimony and bismuth in low oxidation states form aqua-ions? Sources available to me do not give any information. Petergans ( talk) 11:21, 13 April 2021 (UTC)
Asterisks given to Ge, Sb, Po at the dividing line, as well as strong radioactives Fr, Ra, and Es-Lr.
As for transactinoids, aqueous chemistry has only been done for Rf, Db, Sg, and Hs. Given the congeners, though, one should not really expect to see aqua ions for these, and indeed such were not studied in detail. So, actinoids seems a good place to stop. Double sharp ( talk) 08:24, 15 April 2021 (UTC)
See Talk:List of ions in aqueous chemistry for further discussion relating aqua-ions. Petergans ( talk) 11:39, 25 July 2021 (UTC)
I wonder if hydronium ought to be explained briefly, given how most introductory chemistry books cannot resist writing "H+". Double sharp ( talk) 04:12, 14 April 2021 (UTC)
This article mainly discusses metal cations containing water as the ligand. What about anions and metal cations with different ligands? Some of them are also stable in aqueous solution. -- Leiem ( talk) 06:37, 17 August 2021 (UTC)
Electrochemical potentials vary significantly on pH, especially the case where an ionic aquo species (-OH or H3O+) is part of the equation. Solvation in water also affected by pH.
This article glosses over Anion Solvation. Sort of important in e.g. Battery chemistry or Electroplating that Anion mobility plays a part. TaylorLeem ( talk) 01:33, 29 December 2021 (UTC)
Here. Maybe some updates should follow. Double sharp ( talk) 15:28, 28 November 2022 (UTC)
![]() | A fact from Metal ions in aqueous solution appeared on Wikipedia's
Main Page in the
Did you know column on 31 March 2011 (
check views). The text of the entry was as follows:
| ![]() |
![]() | This article is rated C-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||
|
Some of the superheavies might reach that too – Rf appears to be [Rf(H2O)84+ (10.1016/j.nuclphysa.2015.07.013). Admittedly chemistry beyond Lr is quite recent and sketchy. Double sharp ( talk) 16:08, 8 April 2017 (UTC)
FWIW, discussion below has led to the conclusion that we shouldn't discuss superheavies in this article. There we have only theory in the absence of experimentally clear confirmation (or in one case, Rf, just supposition based on similarity of the observed behaviour to the lighter homologue Hf). Also the predictions are very patchy, and calculations become pretty difficult because of need to take into account relativity, and the whole subject seems to be veering off from the focus of the article. Basically, it is a similar case to astatine. This sort of thing is probably better discussed in the individual element articles as almost totally predicted chemistry and indirect evidence. Double sharp ( talk) 07:35, 16 December 2020 (UTC)
I have copied the discussion (below) here to open it up to a wider audience. The issue concerns the placement of Al in the list of metallic elements, shown in a partial long-form periodic table. I proposed the unconventional layout shown below as being more suitable for the subject matter of the article. Both the traditional and proposed layouts have advantages and disadvantages. The layout chosen depends in which criteria are regarded as being more important. What is undeniable is that the atomic number of Al is one more than that of Mg, which is a good reason for placing these elements next to each other. The discussion is opened out to see if a consensus can be reached.
The issue is: which layout should be used in this article for the table of metallic elements. Petergans ( talk) 10:57, 18 May 2018 (UTC)
Li | Be | ||||||||||||||||||||||||||||||
Na | Mg | Al | |||||||||||||||||||||||||||||
K | Ca | Sc | Ti | V | Cr | Mn | Fe | Co | Ni | Cu | Zn | Ga | Ge | ||||||||||||||||||
Rb | Sr | Y | Zr | Nb | Mo | Tc | Ru | Rh | Pd | Ag | Cd | In | Sn | Sb | |||||||||||||||||
Cs | Ba | La | Ce | Pr | Nd | Pm | Sm | Eu | Gd | Tb | Dy | Ho | Er | Tm | Yb | Lu | Hf | Ta | W | Re | Os | Ir | Pt | Au | Hg | Tl | Pb | Bi | Po | At | |
Fr | Ra | Ac | Th | Pa | U | Np | Pu | Am | Cm | Bk | Cf | Es | Fm | Md | No | Lr | Rf | Db | Sg | Bh | Hs | Mt | Ds | Rg | Cn | Nh | Fl | Mc | Lv | Ts | Og |
(Copied from User talk:Double sharp|talk)
I placed Al in group 3 because, in this context of ions in solution it makes more sense. This is not the normal layout convention, but then, neither is the long-form periodic table. Further, there is an explanation in the article, copied below, as to why Al may be considered together with Sc rather than with Ga in terms of periodicity.
I won't undo your edit; please do so if you can accept the motivation for putting Al in group 3 rather than in group 13. Petergans ( talk) 09:13, 15 May 2018 (UTC)
@ Petergans: I again do not think the new layout [1] is an improvement. Firstly, all of these groupings of elements are already apparent on a normal periodic table. Secondly, the transactinides are omitted despite there having already been some aqueous chemistry done on Rf, Db, Sg, and Hs. Thirdly, I remain unconvinced that the changes are actually going to help understanding. For example, if we are going to duplicate La and Ac, then why not Y which behaves like a heavy lanthanide? And again, putting Al on top of Sc neglects the greater similarity of the structure and solvation of the Al3+ cation to the Ga3+, In3+, and Tl3+ cations rather than to the Sc3+, Y3+, and La3+ cations. I completely disagree that Al having an atomic number one more than Mg is a good reason to put them next to each other; otherwise one could use the same reasoning to put Ti and Zr over Ce, as I have previously noted. Pending further discussion I have restored the previous standard 18-column layout, which seems to have remained mostly constant for almost seven years since June 2011 when an IP editor moved Al to its usual position above Ga.
Perhaps we might find a larger audience for this discussion at WT:CHEM? Double sharp ( talk) 15:34, 20 May 2018 (UTC)
Petergans has changed the periodic table picture shown back to his preferred layout; I have moved Al back to being on top of Ga (this time more consistently), because I'm still not convinced that moving it to above Sc is more useful in this context – not the least because the 6-coordinate structure of Al3+ is similar to that of Ga3+ and In3+, but not that of Sc3+ and Y3+. Even papers specifically focused on the topic of metal ions in aqueous solution do not make this change (e.g. 10.1351/PAC-CON-09-10-22). Double sharp ( talk) 12:12, 24 October 2018 (UTC)
It is a fact that the atomic number of Al is one more than the atomic number of Mg. In the present context, it makes sense for these two elements to be shown next to each other and for Al to be above Sc. If this was a periodic table, I would accept the conventional layout, but it is not; the elements in the top right corner are missing from this table as they are not metallic. Petergans ( talk) 13:01, 24 October 2018 (UTC)
I see that labels of static vs dynamic are used in connection to the methods of determination. I think that a more explanation is required for these qualifiers. Perhaps dynamic is intended as a synonym for kinetic or transport properties, from what it can be noticed.-- 5.2.200.163 ( talk) 14:07, 20 June 2018 (UTC)
I think that the article should mention the explicit expression of the hydration number as a function of radial distribution function, which I see mentioned in the article.-- 5.2.200.163 ( talk) 14:23, 20 June 2018 (UTC)
I think it would be necessary to add details about the determination procedure of the residence time of solvent in the first solvation shell.-- 109.166.139.84 ( talk) 21:59, 24 October 2019 (UTC)
The newly added book inserted as Further reading seems to contain such info.-- 109.166.139.84 ( talk) 00:32, 25 October 2019 (UTC)
I see there are some specs re water exchange kinetics, which deserve some questions/clarifications. How is the aqua ion concentration determined?-- 109.166.139.12 ( talk) 21:53, 18 November 2019 (UTC)
Also how is the constant k determined as first-order rate constant? By using a graph concentration of aqua ion [A] vs time, [A](t) which is supposed to be (approximately) a linear function?-- 109.166.139.12 ( talk) 22:09, 18 November 2019 (UTC)
There is another aspect needing clarification, two inconsistent statements about the dimension of rate constant k:
"The unit of the rate constant for water exchange is usually taken as mol dm−3s−1. The half-life for this reaction is equal to loge2 / k. This measure is useful because it is independent of concentration. It has the dimension of time. The quantity 1/k, equal to the half life divided by 0.6932, is known as the residence time or time constant."
-- 109.166.139.12 ( talk) 22:42, 18 November 2019 (UTC)
The inconsistency is between the dimension amount (of substance)/(volume*time) of k and the dimension time for 1/k.-- 109.166.139.12 ( talk) 23:00, 18 November 2019 (UTC)
In the first sentence "rate constant" should be replaced with "reaction rate".-- 109.166.139.12 ( talk) 00:53, 19 November 2019 (UTC)
I see in the article some statement re the determination of hydration number of metal ions by using ion transport number. Some more details are needed.-- 109.166.139.12 ( talk) 21:11, 19 November 2019 (UTC)
If this were a periodic table, I would agree with you, but it is not: it is a table showing which elements are metallic, as its title specified. In this context, placing Al, on its own, above Ga looks odd, and there is nothing in the article text to explain why it is there. At User:Petergans/sandbox I have toyed with the idea of using a standard layout and colouring the non-metallic elements red, but everything I tried was unsatisfactory in one way or another. Petergans ( talk) 11:37, 14 December 2020 (UTC)
@ Petergans: Do you think we should go a little bit further about what happens for these metals? Currently we have just a short uncited remark. My understanding is that in some cases (e.g. W) simple aqua cations are hard to find, even though of course W is chemically clearly a metal, because of tendencies towards cluster formation in the lower oxidation state where cations are likely. FWIW the Persson paper on structures ( doi: 10.1351/PAC-CON-09-10-22) lists Nb, Tc, Ta, W, and Re as lacking aqueous cationic chemistry (for Nb and Ta, I guess it is because to a first approximation these metals have only the +5 oxidation state as the usual one). Unfortunately, I haven't found theoretical studies for this region like I have for the ones near the metal-nonmetal dividing line. Double sharp ( talk) 07:31, 16 December 2020 (UTC)
Surely there should be a section on lanthanides and actinides? Conjecture should be avoided, so perhaps the heavier actinides might be omitted from the table of elements that form metal ions. Petergans ( talk) 21:32, 3 February 2021 (UTC)
The table has been re-organised to long form; this removes possible controversy over the position of lutetium etc.. Early transition metals in rows 2 and 3 are marked as not forming aqua-ions.
Do germanium, arsenic, antimony and bismuth in low oxidation states form aqua-ions? Sources available to me do not give any information. Petergans ( talk) 11:21, 13 April 2021 (UTC)
Asterisks given to Ge, Sb, Po at the dividing line, as well as strong radioactives Fr, Ra, and Es-Lr.
As for transactinoids, aqueous chemistry has only been done for Rf, Db, Sg, and Hs. Given the congeners, though, one should not really expect to see aqua ions for these, and indeed such were not studied in detail. So, actinoids seems a good place to stop. Double sharp ( talk) 08:24, 15 April 2021 (UTC)
See Talk:List of ions in aqueous chemistry for further discussion relating aqua-ions. Petergans ( talk) 11:39, 25 July 2021 (UTC)
I wonder if hydronium ought to be explained briefly, given how most introductory chemistry books cannot resist writing "H+". Double sharp ( talk) 04:12, 14 April 2021 (UTC)
This article mainly discusses metal cations containing water as the ligand. What about anions and metal cations with different ligands? Some of them are also stable in aqueous solution. -- Leiem ( talk) 06:37, 17 August 2021 (UTC)
Electrochemical potentials vary significantly on pH, especially the case where an ionic aquo species (-OH or H3O+) is part of the equation. Solvation in water also affected by pH.
This article glosses over Anion Solvation. Sort of important in e.g. Battery chemistry or Electroplating that Anion mobility plays a part. TaylorLeem ( talk) 01:33, 29 December 2021 (UTC)
Here. Maybe some updates should follow. Double sharp ( talk) 15:28, 28 November 2022 (UTC)