User talk:Petergans

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Activity in ternary solutions

Do you happen to know some sources containing tables with activity coefficients for ternary solutions like for instance sugar-salt-water?--188.26.22.131 (talk) 17:46, 18 February 2013 (UTC)[reply]

Sorry, I can't help with this request. Petergans (talk) 20:41, 18 February 2013 (UTC)[reply]

Scerri figure 6

Eric Scerri, 2012. Equals demo Pganbs-1 above. "Group 3" number is added.

Periodic table, variant Eric Scerri (2012) figure 6

	1	2	3		4	5	6	7	8	9	10	11	12	13	14	15	16	17	18
1	H																		He
2	Li	Be												B	C	N	O	F	Ne
3	Na	Mg												Al	Si	P	S	Cl	Ar
4	K	Ca	Sc		Ti	V	Cr	Mn	Fe	Co	Ni	Cu	Zn	Ga	Ge	As	Se	Br	Kr
5	Rb	Sr	Y		Zr	Nb	Mo	Tc	Ru	Rh	Pd	Ag	Cd	In	Sn	Sb	Te	I	Xe
6	Cs	Ba	La	*	Hf	Ta	W	Re	Os	Ir	Pt	Au	Hg	Tl	Pb	Bi	Po	At	Rn
7	Fr	Ra	Ac	**	Rf	Db	Sg	Bh	Hs	Mt	Ds	Rg	Cn	113	Fl	115	Lv	117	118
				*	Ce	Pr	Nd	Pm	Sm	Eu	Gd	Tb	Dy	Ho	Er	Tm	Yb	Lu
				**	Th	Pa	U	Np	Pu	Am	Cm	Bk	Cf	Es	Fm	Md	No	Lr

Added to WT:ELEM by Double sharp (talk) 15:28, 30 October 2013 (UTC) Copied here -DePiep (talk) 15:19, 14 December 2013 (UTC)[reply]

Please Help

Happy New Year to all

De Piep: I think you misunderstand my intentions. I want to put a proposal up for discussion in the wider community. I would like to present a clear choice along the lines of (crudely)

proposal

current

Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson

The essence of my proposal will be

• Element names in their respective boxes, with actual element highlighted.
• No atomic number or atomic mass
• No colour coding of element boxes
• No before and after side-bars
• No links to other elements

proposal

H

He

Li

Be

B

C

N

O

F

Ne

Na

Mg

Al

Si

P

S

Cl

Ar

K

Ca

Sc

Ti

V

Cr

Mn

Fe

Co

Ni

Cu

Zn

Ga

Ge

As

Se

Br

Kr

Rb

Sr

Y

Zr

Nb

Mo

Tc

Ru

Rh

Pd

Ag

Cd

In

Sn

Sb

Te

I

Xe

Cs

Ba

La

*

Hf

Ta

W

Re

Os

Ir

Pt

Au

Hg

Tl

Pb

Bi

Po

At

Rn

Fr

Ra

Ac

**

Rf

Db

Sg

Bh

Hs

Mt

Ds

Rg

Cn

Fl

Lv

*:

Ce

Pr

Nd

Pm

Sm

Eu

Gd

Tb

Dy

Ho

Er

Tm

Yb

Lu

**:

Th

Pa

U

Np

Pu

Am

Cm

Bk

Cf

Es

Fm

Md

No

Lr

I do not have the capability to create this kind of graphic. All I can do is produce it as a wikitable like my preferred one, above. That's why I have asked for your help.

I want to propose a familiar form of the periodic table whose sole function is to show the position of an element within it. Properties, such as atomic number and atomic mass, are listed as separate items in the chembox and don't need to be duplicated. All discussion about which group an element belongs to etc., which may or may not be controversial, belongs elsewhere in the chembox, or the body of the article. Petergans (talk) 18:04, 1 January 2014 (UTC)[reply]

About PT structure & content (the science). You propose column Sc/Y/La/Ac. That is in the group 3 discussion at WT:ELEMENTS. The discussion is still open, and you and WP:CHEM were invited long ago. A core of that discussion I have written here above. But no way I will support any fork of that discussion. (still, as I said at WT:ELEM, if such a structure is the outcome of the discussion, or it is needed somewhere to illustrate a point, I'll be happy to make it).

About the formatting/tablelayout you propose. I see no advantage in 1. unclickable elements, 2. omitting group numbers and period numbers, 3. omitting the unnamed elements (like element 113).

None of these two topics you mention here are proposed at WT:ELEM. If you have a special usage for this one (both structure and format), please point to the page and the topic for any usefullness. As is said in the WT:ELEM discussion, within a topic anything is possible to explain something (see for example Chemical_element#Abundance). But not for the vanilla PT we use. -DePiep (talk) 12:15, 3 January 2014 (UTC)[reply]

Adding. Above I pointed to Template:Periodic table (nutritional elements). That was to illustrate that we can mark any specific grouping of elements, related to a topic. I just noticed that that PT has a Sc/Y/La/Ac column (and no group, period numbers). That aspect I did not want to illustrate. If and when the content discussion at WT:ELEM about group 3 is closed as proposed, that PT structure will be changed into a vanilla PT. (A Sc/Y/La/Ac column can be present in a PT in an article section where that variant is described). -DePiep (talk) 14:51, 3 January 2014 (UTC)[reply]

One question

Why not show the unnamed elements 113, 115, 117, and 118 on the table? Double sharp (talk) 08:46, 20 January 2014 (UTC)[reply]

Cardinal cubic B-spline

Hi Petergans,

the file http://en.wikipedia.org/wiki/File:Cardinal_cubic_B-spline2.png shows a cardinal cubic B-spline with a maximum value of 4 at its center. To my understanding the maximum value should be 2/3. But as I'm new to splines I'm not sure about it. — Preceding unsigned comment added by 78.43.252.123 (talk) 21:04, 1 February 2014 (UTC)[reply]

Leeds meetup

Hi Peter, the second Leeds meetup will be held on 15 March - see here. Hope to see you there, Bazonka (talk) 21:15, 24 February 2014 (UTC)[reply]

Pitzer ion interaction

Thanks for your feedback on Pitzer ion interaction I have WP:PRODed the article. ~KvnG 21:27, 7 March 2014 (UTC)[reply]

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Structure of electrolytic Solutions - 1959 book

Hello, Petergans! I want to ask seeing your various edits re electrolytes and chemical thermodynamics whether the full text of the source Structure of electrolytic Solutions - editor W. J. Hamer cited on activity coefficient#Concentrated solutions of electrolytes is accessible to you (perhaps at your institution's library)? Thanks.--82.137.9.95 (talk) 15:39, 15 September 2016 (UTC)[reply]

No, it is not Petergans (talk) 08:41, 16 September 2016 (UTC)[reply]

Data source for hydrolysis graphs

Do you have a cite for these graphs:

• File:BeHydrolysis.png
• File:AlHydrolysis.png

I'd love to have higher quality graphs (I can generate them if I had a data source) and/or get them onto commons for wider availability, but we need some reference for the underlying science first. DMacks (talk) 05:12, 25 November 2016 (UTC)[reply]

I created these graphs using my program HySS, which is available as freeware at http://www.hyperquad.co.uk/hyss.htm . There is a link to the publication that describes the chemical and mathematical basis of the program on the that page. I still have the source code. Vector graphics were used to create the images, so that they are scalable. Any suggestions for improvement will be welcome. Please contact me by e-mail (address on the Hyperquad web-site). I can then send you the data files that were used to create the diagrams. Alternatively I can send the numerical data from which the diagrams can be created.Petergans (talk) 11:49, 25 November 2016 (UTC)[reply]

Acidity and basicity constants for metal hydroxides

Hi. I would be interested in your comments on my recent post at Talk:Acid dissociation constant/Archive 1#Basicity and acidity constants in infoboxes for metal hydroxides ?. Dirac66 (talk) 23:54, 18 December 2016 (UTC)[reply]

Merger discussion for Inorganic anhydride

An article that you have been involved in editing—Inorganic anhydride—has been proposed for merging with another article. If you are interested, please participate in the merger discussion. Thank you. --HighFlyingFish (talk) 23:15, 16 June 2017 (UTC)[reply]

Equilibrium Constant

Hi Petergans,

Thanks for the courteous message. I was on the fence regarding whether it is necessary to define reaction quotient. In the end I gave a simplified definition in the first paragraph for the sake of completeness (just as I gave a one sentence definition of what equilibrium means.)

I felt that it is for the benefit of novice readers (with only a rudimentary knowledge of chemistry) to at least know that the reaction quotient is a number varying over time that depends on concentration values. Otherwise, the whole article is incomprehensible, unless they read the reaction quotient page in some detail.

I think if you can further simplify the intro paragraph, please do so, but at least a vague description of what a reaction quotient is should be given.

Alsosaid1987 (talk) 16:27, 19 November 2017 (UTC)[reply]

Hi Petergans:

I'm afraid I have to disagree with your viewpoint in this. I understand what dynamic equilibrium means, and I'm afraid you are the one who has a misconception. If you look at the overall rate constant at which a reaction reaches equilibrium (assuming first-order in both directions), it is (k+k'), and thus, equilibrium is reached via first order decay (i.e., e^(-(k+k')t)). Mathematically speaking, this never reaches 0, and this point was emphasized by R. G. Bergman in his lectures at UC Berkeley. Of course, there is a point at which instrumentation is no longer able to detect any changes, and for practical purposes, a reaction is considered to be complete after 5 half-lives.

This is not dumbing down. I edited the previous version, because some definitions (specifically Kc) contradicted the IUPAC Green and Gold book's definitions. (Being mathematically inclined, I could not tolerate the errors in dimensionality.) Also, I specifically emphasized that for practical systems studied in the laboratory, the time to reach equilibrium is indeed finite for all intents and purposes.

I edited the previous version of this article due to numerous inaccuracies. I am striving for readability in the intro and accuracy in the main body.

Please do not revert just because you found one objectionable statement. Edit!

By the way, I am perhaps not as senior as you are, but I am also an expert in the field as Assistant Professor of Chemistry at the University of Pittsburgh, having previously completed graduate and postdoctoral training at UC Berkeley and MIT, respectively.

Alsosaid1987 (talk) 16:26, 20 November 2017 (UTC)[reply]

150.212.127.88 (talk) 15:51, 20 November 2017 (UTC)[reply]

Hi Petergans,

Just to remind you of the mathematics of the kinetics of an equilibrating system: Consider A<->B with forward and backward rate constants k and k'. And let x=[A]_0-[A]. Then we can write the differential rate law as dx/dt=k([A]_0-x)-k'([B]_0+x). It's not hard to show from there that the integrated rate law is ln((k[A]_0-k'[B]_0)/(k[A]_0-k'[B]_0-(k+k')x))=(k+k')t. Now let x_eq=[A]_0-[A]_eq. At equilibrium dx/dt=0, so the differential rate law gives k[A]_0-k'[B]_0=(k+k')x_eq. Substituting into the integrated rate law gives our final result: [A]-[A]_eq=([A]_0-[A]_eq)e^(-(k+k')t).

This is a result that is quoted in works like Anslyn and Dougherty's Modern Physical Organic Chemistry. Thus, if you accept the view that it takes an indefinite number of half-lives for a radioactive element to decay to nothing, then this is the same. Of course, in real life, if one starts with a mole, then after log_2(N_A * 1 mol) or approximately 79 half-lives, then one would expect only a single atom to be left. The idea of a half-life is not really meant to be applied to a single particle (it could decay in the next moment, or it could last forever). I don't really want to discuss the philosophy... Perhaps "infinite" is a slightly misleading term, but one cannot give a definitive time at which the process is "over". I hope this clarifies things!

Best, Alsosaid1987 (talk) 05:13, 24 November 2017 (UTC) 67.186.58.77 (talk) 05:12, 24 November 2017 (UTC)[reply]

Hi Petergans,

For the equilibrium constant article, I have rewritten the first part of the basic definitions and properties section (with the IUPAC gold book as a guide). Hopefully, this rewritten form should address your concerns.

Best, Alsosaid1987 (talk) 07:41, 24 November 2017 (UTC)[reply]

Hi Petergans,

I would also like to get a sense of why we are in disagreement. There may indeed be a difference between solution and gas phase equilibria, but I think there may be some more fundamental disagreements.

I, as well as the Chem Ed NZ article, derived the kinetics of A<->B type equilibria. I don't think you dispute the fact that mathematically, the result is that equilibrium is approached via exponential decay. I infer that you believe at a certain point, this equation no longer reflects what's going on inside the reaction flask. So I ask you, at what point do you think the exponential approach to equilibrium concentrations breaks down, and for what reason. I would also kindly ask you to provide a source. Note that just because several textbooks you consulted did not explicitly address this question of "how long does it take to reach equilibrium", that does not imply that these textbooks endorse your view that equilibrium is reached at a definitive time.

Secondly, I realize that not all sources state the same (see below), but the IUPAC explicitly states that K_c has units of concentration to the negative power of the particle number change. This is stated on pg. 73 of the Green Book. I do not disagree that for the purposes of Delta G = -RT ln K, one must use a dimensionless version of K. However, that is the purpose of the activity-based thermodynamic equilibrium constant. This is also why we must careful distinguish the concentration, partial pressure, and thermodynamic equilibrium constants. According to the IUPAC, they do not have the same dimensions, and only the last one is unitless by definition.

Note that your current definition of K_c is inconsistent. You describe K_c as K times a quotient of activity coefficients. However, at the same time you state that K_c is a quotient of concentrations. Because activity coefficients are all unitless, these two statements cannot both hold, and that is why I tagged them as inconsistent.

I note that Atkins and dePaula indeed define K_c to be unitless, by defining it such that all concentrations are first divided through by the standard concentration of 1 mol/L, so that numbers going into the quotient all all unitless. However, that is not the IUPAC's definition.

I hope you carefully consider and address these points.

Happy Christmas,

Alsosaid1987 (talk) 19:23, 25 December 2017 (UTC)[reply]

I don't disagree with the kinetic approach. The point of disagreement is with the speed of reaction. When determining equilibrium constants the data are obtained by means of a (generalized) acid/base titration. Most reactions are extremely fast; one waits only a few seconds between titrant additions.^§ Some reactions are noticeably slower, e.g. Ca,Mg with EDTA, but still not requiring more than a minute or so between additions. Incidentally, regarding gas-phase reactions such as the synthesis of ammonia, for the purposes of this article one must assume that a catalyst is present, if needed, to attain equilibrium in a reasonable time. § Most determinations these days are done with autotitators which measure the rate of change of pH after a titrant addition and trigger the addition of more titrant when the rate falls below a predetermined value. Petergans (talk) 20:47, 25 December 2017 (UTC)[reply]

Petergans (talk) 20:47, 25 December 2017 (UTC)[reply]

Excess chemical Potential and electrochemical potential

Hi, I posed a question on in the Wikipedia but there seems to be no expert around who could answer my questions. You appear to me as the expert I want to consult in this question :)

How are the Excess chemical Potential and electrochemical potential related. Let s say I have a solution of Ions of given concentration. Then for every type of Ion, I may provide an excess chemical potential. This excess chemical potential tells me how much e.g. the electrostatic interaction (between the Ions) alters the ideal chemical potential of that kind of ion type. If I write down the Free enthalpy of the system ${\displaystyle G=U-TS+pV=\sum _{i}\mu _{i}N_{i}}$ will I have to add an additional term for the electric potential(${\displaystyle +\sum _{i}z_{i}F\Phi \cdot N_{i}}$) or is it sufficient to write ${\displaystyle \mu _{i}=\mu _{i,ideal}+\mu _{i,excess}}$ ? If the last thing is sufficient, when will I need to add the extra term for the electric potential to the free enthalpy ${\displaystyle G=U-TS+pV=\sum _{i}(\mu _{i}+z_{i}F\Phi )N_{i}}$, where ${\displaystyle {\overline {\mu }}:=(\mu _{i}+z_{i}F\Phi )}$ is the electrochemical potential. Or will the electrochemical potential just give me ${\displaystyle \mu _{i}=\mu _{i,ideal}+\mu _{i,excess}}$? I would really, really appreciate your help and would hope that wikipedia explains this to it s readers. Kind Regards! --129.69.120.91 19:16, 16. Apr. 2018 (CEST) — Preceding unsigned comment added by 129.69.120.91 (talk) 12:13, 3 May 2018 (UTC)[reply]

Sorry, I can't help. My specialty is inorganic chemistry, not physical. Petergans (talk) 18:53, 3 May 2018 (UTC)[reply]

Do you have an idea, whom I could ask? :) --129.69.120.91 (talk) 19:47, 3 May 2018 (UTC)[reply]

This is a very specialized question. I suggest you approach a University professor, but I fear that he will only point you to an advanced textbook. Petergans (talk) 07:35, 4 May 2018 (UTC)[reply]

Osmotic coefficients for multisolute solutions

Hi Petergans! I see that you are the creator of the osmotic coefficient article. Can you mention an example, perhaps from inorganic mixtures of salts in aqueous solution, of using the osmotic coefficient (and their corresponding expressions) for each of the solutes from a mixture of dissolved salts in a solvent like water? Thanks.--109.166.136.19 (talk) 12:47, 13 June 2018 (UTC)[reply]

Speedy deletion nomination of Silicic acid

Hello Petergans,

I wanted to let you know that I just tagged Silicic acid for deletion in response to your request.

If you didn't intend to make such a request and don't want the article to be deleted, you can edit the page and remove the speedy deletion tag from the top.

You can leave a note on my talk page if you have questions.

Xx236 (talk) 08:48, 31 July 2018 (UTC)[reply]

According to you wish I have created Silicic acid as a redirect. I don't know the subject, please verify.Xx236 (talk) 09:47, 31 July 2018 (UTC)[reply]

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Solubility equilibrium — Stoichiometry vs Charge

Hello, I'd like to know why my edit was reverted. The charges are listed for ApBq as (p A[q+] + q B[p-]) but for Tin(IV) Sulfate (or Manganese(IV) Carbonate or etc.), this is untrue. The stoichiometric coefficients give the reduced fraction, so for a metal ion like Sn4+ and an anion like (SO4)2- you have Sn(SO4)2 but the ion charges are 4:2 not 2:1

If you dislike my nomenclature of arbitrarily using "n" for the stoichiometric-to-charge multiple, what variable would you prefer? (For the record, using "p" as in the 1:1 expression above is probably extremely confusing as p is used everywhere else for the stoichiometric coefficient of the first ion, which would be 1 in the case of all three AgCl, CaSO4, and FePO4. The multiple must be its own variable, however we write it.) --RProgrammer (talk) 10:23, 12 September 2018 (UTC)[reply]

Metal ions in aqueous solution

Hello, I have a few comments concerning my edit you reverted:

1. Metal ions in aqueous solution the molybdenum(IV) species formulated as [(H₄O)-Mo-Mo-(OH₄]^4+ Wrong change of oxidation state from II to IV.

I agree that I was wrong about the oxidation number. Please consider, however, that the formula [(H₄O)-Mo-Mo-(OH₄]^4+ is clearly wrong.

As to the correction of the references, I simply checked the original sources: for ref 14 the doi is: 10.1016/S0898-8838(08)60017-3; and for ref 15: 10.1098/rspa.1983.0136

Regards, --Albris (talk) 15:19, 10 November 2018 (UTC)[reply]

Already corrected. Petergans (talk) 22:03, 10 November 2018 (UTC)[reply]

Confusing introductory section on Osmotic pressure

Hello!

While reading the article on osmotic pressure, I noticed that after your edit the introductory part of the article is no longer about osmotic pressure, but about osmosis. The definition of osmotic pressure as of 21/01/2019 isn't stated in the article at all anymore.

I presume removal of definition and the current state of introduction are accidental and should be reverted or corrected while retaining potential other edits? If you don't have plans to rework it further, I will copy the relevant parts from this revision and edit it where necessary.

Greetings,

Argyreia nervosa (talk) 22:03, 21 January 2019 (UTC)[reply]

Done Argyreia nervosa (talk) 15:30, 27 January 2019 (UTC)[reply]

Silicic acid deletion

Hi,
Last year I spent many hours cleaning up the jumble of articles on silicic acid and silicates. Read dozens of articles, etc.
It seems that you were unhappy with that work and nominated the entire page for deletion. However, the overwhelming consensus of that discussion was "keep".
Yet, someone apparently blanked that page anyway, with the result that it was speedily deleted -- and all my work, including the page's history, was lost.
Then the page was re-created but as a link to orthosilicic acid. Which however is just one of the silicic acids.
Then you added a section on silicic acid to orthosilicic acid. Which does not make sense either.
I will try to ask the administrators to recover whatever is possible from the lost material. I hope that, if you have objections to my (or anyone else's) hard work, you will take the time to discuss it, before simply deleting it.
All the best, --Jorge Stolfi (talk) 11:19, 27 March 2019 (UTC)[reply]

I agree, the final section should have been integrated with the introduction. I will look after this. For the rest, I'll put this page on my watch list.

There is a more general problem arising from the traditional use of the term "silicic acid" for silicon dioxide. My feeling is that the placing the section "Oceanic silicic acid" here is questionable; perhaps it belongs in the article silica.

Please note: I am not the person who performed the deletion. Petergans (talk) 22:36, 28 March 2019 (UTC)[reply]

I have asked to be mailed the original contents of silicic acid and will then think about what should be done with those pages.
Meanwhile, who uses "silicic acid" as a synonym of SiO₂? Mineralogists speak of high-silica rocks as "acidic", but I don't recall even them using "silicic acid". It seems as strange as referring to PbO₂ as "plumbic acid".
By the way, it seems that the double Si=O bond is very unstable. Which would mean that SiO₂ is actually an hypothetical molecule that cannot really exist, whether in the solid state or in solution! Even the "metasilicic acid" HO−(Si=O)−OH now seems unlikely; in water, an isolated molecule of it should immediately turn into orthosilicic and remain so.
By the same reason, the oligomers that form when silicates are acidified cannot possibly have exposed Si=O groups. On the surface of such a cluster, there should be only −OH groups attached to silicon atoms. Inside the cluster, the silicon atoms must be connected to each other by −O− bridges, as in quartz and polymeric silicates.
Makes sense? I recall at least one recent article that had studied the structure and growth of those oligomers. i don't recall whether I managed to use and reference it in the article. I hope I have saved the ref somewhere...
All the best, --Jorge Stolfi (talk) 04:05, 31 March 2019 (UTC)[reply]

Use of the name "silicic acid" for SiO₂ is still common for commercial products, as you will find if you Google the term. As to the non-existence of Si=O, this is a very old story. The main factor is the ease of formation of polymeric silicate structures. By contrast, X=O is well established in compounds of phosphorus (V), sulphur(VI) and chlorine(VII); the relative energy of the 3d orbital is lowered in those high oxidation states, so that it can take part in bonding. Petergans (talk) 09:17, 31 March 2019 (UTC)[reply]

I googled "silicic acid" and the first commercial offer that came up was a Sigma-Aldrich catalog page. However, the formula they give is not SiO₂ but rather the "metasilicic acid monomer" O=Si(OH)₂.
Now, I don't know what is in that bottle,

I agree. Who knows what is in the bottle. I know for certain that the formula O=Si(OH)₂ is wrong. I have searched the web and Sigma-Aldrich appears to be the only source for this formula. (PG)

but it is definitely not SiO₂ (because they would have said so if it was), nor O=Si(OH)₂ (because of that "impossible" Si=O double bond). Most likely it is dried "silica gel" with the approximate elemental formula SiO₃H₂. Which is probably a mix of mostly linear polymeric silicic acids with −Si−O− backbone and OH side groups, either cyclic (starting with the dimer [SiO(OH)₂]₂, "disilicic acid") or linear capped with −Si(OH)₃ ends (starting with [(HO)₃Si−]₂, "pirosilicic acid". There may be more complicated branched and polyciclic structures too, as well as some Si(OH)₄ "orthosilicic acid"; but those two must predominate to achieve the elemental formula.
So I am still disputing the claim that "silicic acid" is commonly understood to mean SiO₂.
The existence of silicic acids in solutions of "silica" can be deduced from what are the possible bonds between Si, O (or O^−), and H, and from the empirical fact that acidified sodium silicate solutions take hours or weeks to polymerize and form perfectly transparent hydrogels. Those old papers that you deleted also give evidence based on boiling point, permeability, and such, of the existence of low-molecular-weight "silicic acids" in those solutions, especially after the counterions like Na^+ have been removed by ion-exchange resins.
(It is disconcerting that you blithely erase material that is backed by those apparently careful experiments published in journals, just because they are "old", and then tell me to check commercial catalogs for evidence that "silicic acid" is just another name for silica...)
Given that now ortho- and pyrosilicic acids have been obtained as stable solids, I think that the ball is in the other court: claims that those acids do not exist in aqueous solution should be backed by references to convincing experiments. Would you not agree?
In fact, if there is a substance that is "bogus", "purely unsubstantiated conjecture", it is SiO₂! With those two double Si=O bonds, that molecule would be extremely unstable. I doubt that it exist anywhere, except perhaps as a very rarefied vapor at very high temeratures, or some other exotic environment. The smallest neutral molecule with that elemental formula that looks like it might exist is the cyclic hexamer [SiO₂]₆: six SiO₄ tetrahedra, each sharing an edge (two oxygens) with each of its two neighbors.
So maybe I should blank the silicon dioxide article and replace it by a redirect to unobtanium... 😀
I will try to rebuild the silicic acid article and subsidiary pages, hopefully with enough references to pacify the non-believers. May I ask that you please do not delete my work again without discussion?
All the best, --Jorge Stolfi (talk) 18:56, 8 April 2019 (UTC)[reply]

What I deleted were references to unreliable material from the literature prior to 2017. That is the year when Si(OH)₄ was synthesized. Petergans (talk) 20:05, 8 April 2019 (UTC)[reply]

• Why are those old papers "unreliable material"? A substance that has not been isolated in pure solid form may still exist, and may be confirmed to exist in many ways other than isolation. Even if it is only conjectured to exist, but with reasonable arguments, it still deserves an article.
  Are there any recent articles claiming that those preparations described in old articles do not contain silicic acids, but something else? I don't recall seeeing any...
  I edited cobalt(III) chloride recently. Some old articles claim to have synthesized it, but later articles explicitly say that whatever those guys got was not CoCl₃. So of course I did not rely on those old claims. But other slightly "less old" articles identified it in vapor at ~800 C, and they seemed very carefully done, so of course I had to use those. That compound, like NO₂, definitely exists -- even if it has not been isolated pure or as a bulk solid, and may never be. --Jorge Stolfi (talk) 11:14, 11 April 2019 (UTC)[reply]

Before that, the term "silicic acid" was used generically for silicon dioxide and related substances, such as "silica gel". Petergans (talk) 20:05, 8 April 2019 (UTC)[reply]

• Well, I still dispute that claim. Those who believed in the existence of silicic acids would obviously not do that. Those who did not believe in them would call silica "silica": why would they call it "silicic acid"? --Jorge Stolfi (talk) 11:14, 11 April 2019 (UTC)[reply]

It is still used today with many products of the cosmetics industry. Petergans (talk) 20:05, 8 April 2019 (UTC)[reply]

• Ah, so maybe that mis-naming is specific to the cosmetic industry? Do you mean those "exfoliaton" creams? I can imagine that calling the abrasive ingredient "silicic acid" could be more chic than calling it "silica"... --Jorge Stolfi (talk) 11:14, 11 April 2019 (UTC)[reply]

My edits were based on the fact that situation has now changed.

I have revised the whole article in my sandbox and will post the revision after completing this message. Plase check my user page for some useful personal information. Petergans (talk) 20:05, 8 April 2019 (UTC)[reply]

• OK, I will wait. Meanwhile, note that the descriptions of the hydrothermal method for making synthetic quartz crystals assume that the silica in solution is orthosilicic acid

Not so. There is no need to speculate as to what species are present in solution. All that matters is that the dissolution and recrystallization do occur.

• (because "colloidal silica" particles could not form crystals). Also, consider what silicon compounds could be present in those solutions that one gets by acidifying solutions of sodium silicate, or removing the Na by ion exchange.

That's speculation. What is known is that all attempts to make solution with higher concentration's of silicic acid have failed as a precipitate forms. Put quantitatively, at higher concentrations, the equilibrium

Si(OH)₄ (solution) ⇌ SiO₂xH₂O (solid)

favours the precipitate because of its low solubility.

• PS. I have known your qualifications for quite a while; but we are not disagreeing on chemical facts, are we? The issue is entirely which facts are appropriate for Wikipedia, and how to present them. Since wikipedia is meant for non-specialists, the opinion of non-specialists should have some weight too, wouldn't you agree? 😊
  All the best, --Jorge Stolfi (talk) 18:03, 11 April 2019 (UTC)[reply]

Conjecture and speculation have no place in Wikipedia. Predictions based on known facts are OK, like Pauling's prediction of a pK value for Si(OH)₄. Petergans (talk) 10:35, 12 April 2019 (UTC)[reply]

Concerns

This text is not appropriate for obvious reasons "The chemistry, formulation, mechanisms of action and pharmacodynamics have been reviewed".[1] It is a bland statement that says nothing. Best Doc James (talk · contribs · email) 18:27, 20 April 2019 (UTC)[reply]

A summary of the contents in a review article is not inappropriate. Petergans (talk) 23:00, 20 April 2019 (UTC)[reply]

Not sure what you mean? Providing key points from the review is appropriate. Simple saying a review was done does not really add much. Doc James (talk · contribs · email) 23:27, 20 April 2019 (UTC)[reply]

Additionally, this is a medical claim "Bis(8-Aminoquinoline) derivatives have been shown to be specific for the chelation of copper and to restore copper homeostasis in the brain of Alzheimer's patients."

What text in the source supports it? Robert, Anne; Benoit-Vical, Françoise; Liu, Yan; Meunier, Bernard (2019). "Chapter 2. Small Molecules: The Past of the Future in Drug Innovation?". In Sigel, Astrid; Freisinger, Eva; Sigel, Roland K. O.; Carver, Peggy L. (Guest editor) (eds.). Essential Metals in Medicine:Therapeutic Use and Toxicity of Metal Ions in the Clinic. Vol. 19. Berlin: de Gruyter GmbH. pp. 17–48. doi:10.1515/9783110527872-008. ISBN 978-3-11-052691-2. {{cite book}}: |editor4-first= has generic name (help); |journal= ignored (help)</ref>

Can you please provide a quote. Please note that patients are people, mice are not patients. Doc James (talk · contribs · email) 19:06, 20 April 2019 (UTC)[reply]

The first sentence above is, in effect, a direct quote from the article that you cite above, which I have read. I have also taken the citation referring to tetradentate monoquinoline compounds from that chapter. My perspective is based on inorganic chemistry - see my talk page for details. Without such chemistry the development of new metal-targeting drugs (copper in this case) would be all but impossible. Unfortunately it takes many, many years of laboratory, animal, pre-clinic and clinical trials before new chemical compounds can be approved for clinical use. Petergans (talk) 22:56, 20 April 2019 (UTC)[reply]

Okay I am not seeing that text and have looked through the paper.

Can you provide me a quote? Agree research on new medications takes a long time. Thanks Doc James (talk · contribs · email) 23:32, 20 April 2019 (UTC)[reply]

This is not a medical claim. Specificity in this context refers to binding selectivity. Measured binding constant values are given in the cited article; they are the basis for the prediction that the ligands should remove very much more copper than zinc from the brain. Petergans (talk) 08:09, 21 April 2019 (UTC)[reply]

Polonium 210 Half Life

Hi Petergans! Looking back on our to-and-fro on this issue:

• Apologies if some of my comments were unappreciative of your efforts and good intentions. I disagree with your interpretation, but civility costs nothing.

• I don't get that the precision quoted is an "impossible howler". You may be right, but it could be frustratingly difficult to get your interpretation through Wikipedia with its restrictions on Original Research. It would be unfortunate if this degenerates into a revert war, wouldn't it? I'm not sure if the right venue to thrashing out this issue would be the Talk:Polonium-210 page (probably) or one of our personal talk pages. My experience of Wikipedia makes me guess that it's best, for the moment, to leave the page with the 138.376 figure that you find objectionable.

• I didn't have to look up the 138.376 figure! It's now ground into my memory! People wonder why we argue like this, but win or lose we learn new things en route, right?

Ewen (talk) 18:45, 1 August 2019 (UTC)[reply]

Burgess 1978 chapter 5 Solvation numbers

Hello, Petergans! I have noticed your edits at ion association citing the book by Burgess book/source, especially chapter 5 re solvation. Therefore I ask you whether the mentioned chapter contains some formulae and derivations similar to those which can be encountered at talk:solvation shell#Solvation number. Thanks--109.166.139.84 (talk) 21:00, 22 October 2019 (UTC)[reply]

Water exchange residence time in metal aquo complexes

Hello! I see that the metal ion aquo complex articles mention terms such as "water exchange residence time". How do you consider the addition of more details in these articles, from sources like Burgess and the mentioned 1973 book by Felix Franks re Aqueous Solutions of Simple Electrolytes?--109.166.139.84 (talk) 01:09, 25 October 2019 (UTC)[reply]

Lead(II) nitrate has been (negatively) edited under your name

Hi Petergans,

The Lead(II) nitrate page, an old Featured Article of the Wikiproject Chemicals, has recentely been edited under your name, removing very significant sections of the text. Assessing these, I can hardly see that this has been fully intentional, as the quality of the article has grossly deteriorated. As such, logically, the article is now FA Review, and I would like to re-instated the deletions that you (and many others) have done. Please comment if you have significant other intentions, or if those deletions were indeed unintentional. Wim van Dorst (talk) 13:24, 26 October 2019 (UTC).[reply]

This article was featured on March 8, 2007. An article concerning a single chemical compound would not be acceptable as an FA today. The lede as it stands is not an accurate summary of the contents. The use of lead nitrate has been largely discontinued because of toxicity concerns. Petergans (talk) 10:15, 27 October 2019 (UTC)[reply]

• Thanks for your reply, Peter. The facts you state are fully true. Yet, I would appreciate to learn what your intentions were (and are) regarding the bold editing that you did, leaving the article so abbreviated, also with significant information removed. Are you not done yet? Wim van Dorst (talk) 13:47, 27 October 2019 (UTC).[reply]

My intention was to remove repetitious material. The lead should summarize contents of wide significance; repetition of content word for word is very poor practice. Petergans (talk) 14:26, 27 October 2019 (UTC)[reply]

(Just in case you didn't notice, DePiep is regrettably suspended until March. So don't expect a reply anytime soon). --John Maynard Friedman (talk) 17:36, 15 January 2020 (UTC)[reply]

acetic.png

in acetic.png does pOH follow pOH + pH = 14?

Yes. When there is an equilibrium H^+ + OH^- = H₂O it follows that [H^+][OH^-]=10^-14. There is an underlying assumption, that the concentration [H₂O] is independent of pH, which is valid for all but the most concentrated solutions. Petergans (talk) 20:13, 15 January 2020 (UTC)[reply]

Not sure what this does?

[2] best Doc James (talk · contribs · email) 11:23, 10 January 2020 (UTC)[reply]

It's obvious. It ensures that the table is right-justified. I guess that we are using different web-browsers and that you already saw it as right-justified on the screen, whereas I saw it as left-justified. Petergans (talk) 20:01, 15 January 2020 (UTC)[reply]

"mol dm-3"

Regarding this edit, I want to remind you that I did not ignore your old comment on my talk page and actually have replied to it, providing enough information to support my opinion that "mol/L" (or "mol/l") should be preferred to "mol dm^−3" (and surely to its crippled representations "mol dm^-3" and "mol dm-3"). But you have never explained why you don't consider my arguments valid. Anyway, I can reiterate that "mol/L" (or "mol/l") is perfectly acceptable in terms of SI rules and IUPAC recommendations, convenient and commonly used (in particular, in most Wikipedia articles), so there is no reason to write it as "mol dm^−3". — Mikhail Ryazanov (talk) 03:14, 16 April 2020 (UTC)[reply]

Petergans, I have answered to your new comment on my talk page. If for some unknown reason you prefer to discuss there instead of continuing here. — Mikhail Ryazanov (talk) 21:58, 16 April 2020 (UTC)[reply]

Coactive nonmetals and halogen nonmetals

G’day Petergans

I write to gauge your thoughts about a proposal to change the nonmetal categories appearing in our periodic table from {reactive nonmetals} and {noble gases} to {coactive nonmetals} {halogen nonmetals} and {noble gases}

thank you, Sandbh (talk) 07:28, 10 August 2020 (UTC)[reply]

*     *     *

Context. There has been some discussion about nonmetal categories at WP:ELEMENTS.

I suspect most active members of that project (including me) would agree to divide the reactive nonmetals i.e. the nonmetals other than the noble gases, into two relatively clear and self-descriptive categories. However, since the WP periodic table was created, we haven't found a good way of doing this.

I caveat the expression "relatively clear" by what we say in our periodic table article:

"Placing elements into categories and subcategories based just on shared properties is imperfect. There is a large disparity of properties within each category with notable overlaps at the boundaries, as is the case with most classification schemes."

That said, didactically speaking, the use of "natural" classes or clusters to organise information supports content processing.

In Wikipedia history, the categories of "other nonmetals" and halogens are the two most enduring nonmetal categories used in our periodic table. That was until we started complaining about what a non-informative category name "other nonmetals" was.

Now, the halogen category is consistent with the traditional aspect of teaching the periodic table by contrasting the alkali metals with the halogens.

Long story short, we don’t currently have a halogen category because we weren't able to satisfactorily characterise the other nonmetals as something other than {other nonmetals}. So we decided that they and the halogen nonmetals would collectively be the reactive nonmetals.

Developments. A couple of articles in the peer-reviewed literature have prompted me to revisit this question. The first is "Metals are not the only catalysts", in Nature. The second is "Organising the metals and nonmetals", in Foundations of Chemistry (disclaimer: 1, authored by me; 2, the scheme I propose is not the same as that in this article).

The upshot is that the other nonmetals can be characterised by their:

1. tendency to form covalent or polymeric compounds;
2. prominent biological roles;
3. proclivity to catenate i.e. form chains or rings;
4. multiple vertical, horizontal and diagonal relationships;
5. uses in, or as, combustion and explosives;
6. uses in organocatalysis; and
7. dualistic Jekyll (#2) and Hyde (#5) behaviours

The first six properties of the nonmetals in this part of the periodic table are documented in the literature. #7 is an observation by me.

Coactive. In light of properties 1, 3, 4 and 6, I suggest the term "coactive nonmetals" would be a good way of referring to the other nonmetals. The remaining nonmetals (F, Cl, Br, I) then become the halogen nonmetals, thus restoring the pre-eminence of this category. Here, we show astatine as a post-transition metal since condensed astatine is expected to be a full-fledged FCC metal.

"Coactive" means, "acting in concert; acting or taking place together". That seems like a good adjective wrt the covalent compounds of H, C, N, O, P, S and Se. For their polymeric compounds, e.g. of H, N, O or S, the connection is to the linked nature of their repeating structural units. That is how the literature tends to deal with the nonmetals, except that it has no common term for the first category. There is also the catalytic conation of "coactive".

The literature. Bear in mind the expression coactive nonmetals is not found in the literature.

That said, the complementary term "coactive metal" is found in literature, in the following senses:

• "…adding a coactive metal (such as Pt, Ir, or Rh metal)"
• "The same set of experiments was performed in presence of other co-active metal ions Fe +2, Fe +3, Co +2, Ni +2, Mn +2, Cd +2, Ca +2, Mg +2…".
• "It is of great interest and challenging to improve new catalysts that consist of any of those components and new active metal component (ie co-active metal, promoter)."

There are several other references in the literature to "co-active" elements, materials or substances, including manganese, iron, nickel, cobalt and plutonium.

In the endeavours by WP:ELEMENTS to nail the other nonmetals, we will have now gone full circle from the original {other nonmetals and halogens} → {polyatomic nonmetals and diatomic nonmetals} → {reactive nonmetals}. Now we have a putative categorisation scheme for going from {reactive nonmetals} → {coactive nonmetals} and {halogen nonmetals} that would fulfil the worthy intentions of our predecessors.

Question: Is "coactive nonmetal" a neologism or is it a descriptive phrase, c.f. "coactive metal"? If there are coactive metals does this suggest there are coactive nonmetals? The other nonmetals category is well enough seen in the literature. The covalent-polymeric, biological, catenative, interlinked, combustive/explosive, and organocatalytic properties of the nonmetals in this part of the periodic table are documented in the literature. Historically, and as noted, the "other nonmetals" category is the most enduring nonmetal category used in the Wikipedia periodic table, until we started complaining about what a non-informative category name this was. Do we now have enough content, in pursuit of a better encyclopedia, to support a change back to a binary categorisation of the nonmetals as coactive (formerly other) nonmetals, and halogen nonmetals? ♦

Periodic table (aqueous chemistry)

Dear Petergans

I've edited the article to say that, "No agents producing complexes or insoluble compounds are present other than HOH and OH^− ", and added a citation. Per Greenwood & Earnshaw, p. 1161, [Pt(H₂O)₄]₂^+ is a complex of Pt^II, and does not therefore count as I understand it (thank you for the page number). I have therefore re-reverted your edit. If there are any more errors please let me know and I'll fix them. Sandbh (talk) 00:01, 17 July 2021 (UTC)[reply]

I don't understand why Pt(II) has been excluded. Anyway, there are numerous other inconsistencies in the table, which arise from the wide range of oxidation states that are included. Many of the irregularity of the periodic trends in this table are incomprehensible. Also there are contradictions with the table shown in the article's introduction. For example, there was no relevant information for the trans-actinides beyond Californium at the time I wrote that section. Petergans (talk) 08:15, 17 July 2021 (UTC)[reply]

Pt^+2, in pure aqueous solution, is not there as it does not appear in any of the sources cited. Schweitzer & Pesterfield (2010, p. 332) say, "Reaction of AgClO₄ with PtCl₄^−2 gives the Pt^+2 cation." Since the table is about stable cationic or anionic species, within the range of pH 0 to 14, −3 to 3 V, there certainly will be cases of multiple oxidations states e.g. Cr^2+ at > –0.9 V and Cr^3+ at > –0.42 V. Neither water nor the elements care about irregularities that may be regarded by humans as incomprehensible. The data are what the data are. Data past Cf is available from e.g. Wulfsberg 2018 (p. 310). Sandbh (talk) 07:51, 18 July 2021 (UTC)[reply]

"Preparation and Properties of the Tetraaqua-Platinum(II) Ion in Perchloric Acid Solution, Elding, Lars Ivar (1976) Inorganica Chimica Acta 20(1) p.65-69". This demonstrates that the table is unreliable. Petergans (talk) 08:14, 18 July 2021 (UTC)[reply]

Thank you for the cite. The table only applies to aqueous solutions in which no agents producing complexes or insoluble compounds are present other than HOH and OH. That is not the situation here, as I understand it. Sandbh (talk) 11:42, 18 July 2021 (UTC)[reply]

”Platinum forms no aquo-ions, so strong is its tendency to form hydroxy-species. Alternatively, if suitable ligand anions, such as chloride, are available in an aqueous reaction mixture, it complexes with them.” Cotton & Hart 1975, The Heavy Transition Elements, p. 108. Sandbh (talk) 12:04, 18 July 2021 (UTC)[reply]

From the paper cited above - "Dilute solutions of the square-planar tetra-aqua complex pt(H2O)42+ have been prepared in a 1.00 M perchloric acid medium by addition of excess silver(I) perchlorate to potassium tetrachloroplatinate(II), equilibration at 70°C, filtration of the silver chloride precipitate, and subsequent separation of the excess silver from the solution by electrolysis. The complex has also been prepared (my italics)by addition of mercury(II) perchlorate to tetrachloroplatinate(II) solutions. Petergans (talk) 14:47, 18 July 2021 (UTC)[reply]

So there are two ways of preparing this complex? Each of which involves the presence of anionic species such as Cl− or ClO₄^−, in addition to HOH and OH^−? Sandbh (talk) 00:47, 19 July 2021 (UTC)[reply]

In this article the anion is completley irrelevant, except in the section on ion-pairing. Hydrolysis is generally treated as a separate topic. Petergans (talk) 07:33, 19 July 2021 (UTC)[reply]

In the wp Periodic table (aqueous chemistry) article the presence of an anion, other than OH^–, is completely relevant as per the citations, and as the article notes: "No agents producing complexes or insoluble compounds are present other than HOH and OH−.[1]" Sandbh (talk) 07:46, 19 July 2021 (UTC)[reply]

Perchlorate is not relevant, it's basically a non-coordinating anion here. [[User:Double sharp|Double sharp] (talk) 15:10, 20 July 2021 (UTC)[reply]

As posted above:

”Platinum forms no aquo-ions, so strong is its tendency to form hydroxy-species. Alternatively, if suitable ligand anions, such as chloride, are available in an aqueous reaction mixture, it complexes with them.” Cotton & Hart 1975, The Heavy Transition Elements, p. 108. Sandbh (talk) 12:04, 18 July 2021 (UTC)

​Petergans: The PT of stable aquo-ion species in aqueous solution has been updated. The article concerned is now called List of ions in aqueous chemistry. Before reposting a link at Metal ions in aqueous solution comments would be appreciated. Thanks Sandbh (talk) 06:29, 25 July 2021 (UTC)[reply]

Disambiguation link notification for September 8

An automated process has detected that when you recently edited List of aqueous ions by element, you added a link pointing to the disambiguation page Selenite.

(Opt-out instructions.) --DPL bot (talk) 05:59, 8 September 2021 (UTC)[reply]

Question re aqueous ions

I notice that in your user sandbox version of the list of aqueous ions by element, you have a separate table row for each oxidation state, whereas the mainspace version uses just one table row for each element, separating the oxidation states with horizontal rules.

My question: are you doing this way to make it easier to edit or to improve the appearance? YBG (talk) 00:59, 27 September 2021 (UTC)[reply]

Both. There are obvious gaps that will need to be filled; using one row for each OS will make it easier for non-experts to do edits. Regarding appearance, repeating the oxidation state 3 times in a line of the table is both excessive and pointless. I have tried different ways to incorporate the OS in another column, but nothing was better than the current version in my sandbox. Incidentally, I did try more than once to transfer the sandbox contents to the article page, but each time user:DePiep reverted immediately. Petergans (talk) 08:52, 27 September 2021 (UTC)[reply]

Thank you. DePiep has reverted because he is following WP:BRD: You Boldly made a significant change to the format of the table, he Reverted it, and now, if you still wish to make that change, you should start a Discussion to reach a consensus in favor of your form instead of the status quo.

I think the reason no one has voiced any interest in your sandbox form is that it is not ready for prime time. This will become readily apparent if you try to sort the table by element or Z. But there is a way around this, and with your permission I will attempt to implement it in your sandbox. You of course would be free to accept it as you continue to develop your sandbox, or you could reject it. But I think that when you see it you will find it preferable, and I think others will also, though I cannot say whether they would be convinced to support it in place of the status quo.

YBG (talk) 15:56, 27 September 2021 (UTC)[reply]

I did check that sorting works: it has to be repeated twice to get back to the original starting point.

P.S. In the past user:DePiep has been banned from editing. This time he's sailing very close to the wind with peremptory reversion rather than initiating a discussion himself. His actions amount to starting an editing war over presentation; I won't have anything to do with it. Petergans (talk) 09:13, 28 September 2021 (UTC)[reply]

There’s no BRD requirement for the reverter to initiate the discussion. Sandbh (talk) 10:58, 28 September 2021 (UTC)[reply]

@Petergans:: it has been explained to you multiple times and by multiple editors when and when not to make such edits, why and why not, and especially how to achieve making them wikiwise. And btw, pinging people is intended for direct addressing like in asking or inviting, not for castion WP:BAD FAITH aspersions. -DePiep (talk) 11:29, 28 September 2021 (UTC)[reply]

Nonmetal

Hello Peter

I was wondering if you'd be in a position to support my nomination of nonmetal at FAC here? It so far has two supports and one (inconsequential) oppose. No obligation. Thank you, Sandbh (talk) 22:22, 19 November 2021 (UTC)[reply]

Group theory

I can absolutely sympathise with your reaction, but as I said on the talk page, I think the impulse behind the edit of yours that was reverted was sound. If you would reconsider, I'd be willing to assist in adjusting your text so to improve the chances of acceptance. — Charles Stewart (talk) 21:05, 26 March 2022 (UTC)[reply]

Thank you for your sympathetic message. I've really lost interest in pursuing this matter. There are many other relevant articles: molecular symmetry, group theory#chemistry and materials science and crystal structure is just a small selection. It's a pity that the main article is so weak on applications, but there it is. Petergans (talk) 07:17, 27 March 2022 (UTC)[reply]

This is quite reasonable. Should you ever change your mind, do drop me a line. — Charles Stewart (talk) 09:49, 27 March 2022 (UTC)[reply]

Double group

Rather than deleting the sections in question, it might have been better to add tags requesting clarification as to why someone thought they should be included since the connection is at best unclear. After all, someone spent a bunch of time writing up those sections. If they are indeed relevant it needs to be made clear, and I do agree that it’s unclear at present. I’ll try adding some tags and we’ll see what happens. KeeYou Flib (talk) 16:03, 28 March 2022 (UTC)[reply]

Well, not much it seems. Unfortunate. KeeYou Flib (talk) 04:28, 30 March 2022 (UTC)[reply]

April 2022

Hello. This is a message to let you know that one or more of your recent contributions, such as the edit(s) you made to Double group, did not appear to be constructive and have been reverted. Please take some time to familiarise yourself with our policies and guidelines. You can find information about these at our welcome page which also provides further information about contributing constructively to this encyclopedia. If you only meant to make test edits, please use your sandbox for that. If you think I made a mistake, or if you have any questions, you may leave a message on my talk page. Thank you. Mathsci (talk) 15:32, 3 April 2022 (UTC)[reply]

May 2022

Please stop your disruptive editing.

• If you are engaged in an article content dispute with another editor, discuss the matter with the editor at their talk page, or the article's talk page, and seek consensus with them. Alternatively you can read Wikipedia's dispute resolution page, and ask for independent help at one of the relevant noticeboards.
• If you are engaged in any other form of dispute that is not covered on the dispute resolution page, seek assistance at Wikipedia's Administrators' noticeboard/Incidents.

If you continue to disrupt Wikipedia, you may be blocked from editing. Mathsci (talk) 12:51, 14 May 2022 (UTC)[reply]

You have made three reverts on Talk:Double group (magnetochemistry) and Double group (magnetochemistry); twice you have removed "tags' on the article. This edit[3] was one of the most disruptive: because of WP:TPG, users' edits cannot be deleted on an article talk page. If these disruptive edits continue, you are quite likely to be reported at WP:AN3. Mathsci (talk) 12:58, 14 May 2022 (UTC)[reply]

FYI

Please don't add my user name on your user page as some kind of complaint — I have just removed the specific reference to me. You are welcome to add content to Double group (as is happening now), and it is unlikely that anybody will object. Thanks, Mathsci (talk) 11:11, 24 May 2022 (UTC)[reply]

Notification

There is currently a discussion at Wikipedia:Administrators' noticeboard/Incidents regarding an issue with which you may have been involved. The thread is User:Mathsci at Double group. Thank you. D.Lazard (talk) 15:01, 13 June 2022 (UTC)[reply]

Double group again

What kind of dispute resolution do you prefer for double group? The text as it stands is clearly not acceptable (and reverting to it is certainly not a minor edit).

IpseCustos (talk) 14:38, 25 June 2022 (UTC)[reply]

It is not clear to me what you think needs doing. My impression is that you want to include some pure mathematics which, though relevant, would be unintelligible to non-mathematicians. I have previously removed all material that only someone who has studied mathematics at degree level would understand. My approach is based on the chapter on double groups in Cotton's book, which does not go into the kind of mathematical detail that you appear to favour.

An aggravating issue is poor treatment of double groups in the mathematical articles in Wikipedia; in fact there is hardly anything in those articles that relates to applications in the real world. To overcome this problem the article was renamed "Double group (magnetochemistry)", but, regrettably, the name was changed back to "Double group" a month afterwards. Petergans (talk) 17:26, 25 June 2022 (UTC)[reply]

I agree, for what it's worth, that the mathematical background required to understand that article should be kept as simple as possible; removing all mathematics from the article (which isn't what you did) is not the right way to go about it, though.

You made a sweeping edit, removing about two thirds of the article text; I disagreed with it; the thing that needs doing now is to revert it and discuss, rather than edit-warring to keep your version.

In addition, what mathematics you left in or introduced to the article, as it stands, is unhelpful at best. I fixed several points but you reverted all of them.

Sorry to be blunt, but some of these statements are on a level with the "howlers" you mention on your user page.

Discussing a mathematical object, which is what a double group undoubtedly is, without providing a rigorous definition is unacceptable to mathematicians for very good reasons. The definition isn't long or complicated (it's the preimage in Spin(3) of a subgroup of SO(3)), and I wouldn't mind seeing it in a "mathematical background" section only, but it needs to be there. IpseCustos (talk) 18:53, 25 June 2022 (UTC)[reply]

This is the nub of the disagreement: it's not just a mathematical object. Indeed, Tsukerblat's book, Ch. 10, pp. 245-253 also contains no mathematics other than citing the equation

${\displaystyle \chi ^{J}(2\pi +\alpha )=-\chi ^{J}(\alpha )}$

The rest of the chapter is about how to understand and use the character tables. Of course the cited books are about the applications of group theory and have more extensive treatments of point groups in earlier chapters. The thing that I am stressing is that this chapter contains all that scientists need to know about double groups.

I suggest that the right place for background theory would be a new sub-section in Group theory#Chemistry and materials science, or another place in the main article. There is certainly a need for it. The key issue is the relationship between nuclear spin and the symmetry operations of identity and R. Apart from that, the direct product of two groups is essentially a trivial matter. Petergans (talk) 20:34, 25 June 2022 (UTC)[reply]

I couldn't disagree more. And, again, why do you think this relates to direct products? It simply doesn't.

Spin(3), and I do think the article does a horrible job of explaining that, is precisely the group of "generalized rotations" where a rotation by 360° is not the identity (but a rotation by 720° is, as it has to be). It's not a direct product. It doesn't contain the ordinary group of all rotations as a subgroup. You cannot find a consistent representative in Spin(3) of the rotations by 180°, so you can't go back to Spin(3) from SO(3) without losing all structure. We can embed rotations by <180°, and that is the reason for the somewhat lazy notation of identifying some rotations in SO(3) with some "generalized rotations" in Spin(3), but they behave differently once you reach the threshold of 180°.

And, no, group theory is an article about all of group theory, and the very special case of discrete subgroups of Spin(3) isn't important enough to warrant inclusion there. Instead, it's treated in spin group, where it belongs. I pointed the link there, you reverted that. IpseCustos (talk) 21:39, 25 June 2022 (UTC)[reply]

double group has an RFC

double group has an RFC for possible consensus. A discussion is taking place. If you would like to participate in the discussion, you are invited to add your comments on the discussion page. Thank you.

IpseCustos (talk) 18:58, 26 June 2022 (UTC)[reply]

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Antimonide bromide

Hi Peter, I have finally published Antimonide bromide as a mainspace article. I have numerous other mixed anion compound drafts in my user space. See https://en.wikipedia.org/w/index.php?title=Special%3APrefixIndex&prefix=Graeme+Bartlett%2F&namespace=2 if you are interested. Graeme Bartlett (talk) 00:37, 4 May 2023 (UTC)[reply]

Protonation statuses of ADP and ATP under ATP-Synthase conditions

Hi there, as you've created the file:ATP_protonation.png, maybe you can help me: trying to understand what's happening during composition of ATP from ADP and vice versa in detail, I'm permantently stumbling over the commonly cited standard equation of the ATP-synthase reaction where ADP reacts with inorganic phosphate to ATP and water (or vice versa) without mentioning any electrical charges, while inorganic orthophosphate in reality has three negative charges, so the resulting ATP should acquire them too. In consequence, this widespread "equation" actually shouldn't deserve this name neither with respect to its charge balance nor the atoms balance, since the created water would require another hydrogen atom which can't come from true PO₃^4-. OTOH, pure phosphoric acid instead of phosphate would fulfill at least the atoms balance, but I doubt whether it's really involved in this reaction under physiological conditions. So who actually takes part in that reaction, and in which state of protonation? Can you help? Greetings, Qniemiec (talk) 14:27, 26 July 2023 (UTC)[reply]

Hi there, have found the answer in meantime by myself: it's not true PO₃^4- playing the role of "inorganic phophate" under physiological conditions (as to be found in some figures of the ATP synthesis equation), but once or twice protonated phosphate, i.e. HPO₃^3- in equilibrium with H₂PO₃^2- that actually reacts as the "inorganic phosphate". Unfortunately, you also missed to include the charges of the three ATP versions in your file, so your ATP should actually be ATP^4-, ATPH actually ATPH^3- and ATPH₂ actually ATPH₂^2-. Would be helpfull to fix it. Greetings, Qniemiec (talk) 09:22, 9 August 2023 (UTC)[reply]

Nonmetal

Hi Peter

I have relisted Nonmetal at WP:FAC, if you have time to comment. Thank you. Sandbh (talk) 12:20, 27 September 2023 (UTC)[reply]

Leeds Wikipedia meetup on Saturday 4th May

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20:35, 7 April 2024 (UTC)

Proposed deletion of File:Chromyl chloride upright.jpg

The file File:Chromyl chloride upright.jpg has been proposed for deletion because of the following concern:

Created because the original image was rotated. The original image was fixed three days later (18 dec 2011) and now this is a duplicate.

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Please consider addressing the issues raised. Removing {{proposed deletion/dated files}} will stop the proposed deletion process, but other deletion processes exist. In particular, the speedy deletion process can result in deletion without discussion, and files for discussion allows discussion to reach consensus for deletion. ZandDev 12:46, 11 July 2024 (UTC)[reply]