Wikipedia talk:WikiProject Chemistry

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Removal of Chemistry Portal from the template, put it back[edit]

Just because the portal has been abandoned does not mean that the portal is useless. There is valuable information on the portal, especially if a person is interested in the quickly seeing the vocabulary for a field and not just reading an encyclopedia article. Unless the plan is to remove the PORTAL parameter from all of the WikiProject templates, it should be put back. Leave it to the reader to judge the usefulness of the information on the portal page. Use case example: a person is learning a foreign language and needs to learn the most important words in Chemistry. The Chemistry portal page will give them that information where the Chemistry article will not.

Portals are setup to do rotations of articles automatically. As long as the choice of articles is contained in the Top or High category, if code is written to randomly choose an article from one of those two categories by just grabbing the introduction automatically (TextExtracts), it does not need to be maintained in order for it to work. Zzmonty (talk) 07:55, 25 July 2018 (UTC)

Debate on the correct values for the pKa of water and hydronium[edit]

A number of Wikipedia articles concerning acids (e.g. strong acids, hydronium, pKa, etc.) are not in agreement when discussing the pKa of water and hydronium. This inconsistency reflects an ongoing "debate" on which standard state should be used when calculating the values. The most recent (and comprehensive) papers to discuss this topic are:

J. Chem. Educ., 2017, 94 (6), pp 690–695 DOI:
Helv. Chim. Acta, 2014, 97 (1), pp 1-31 DOI:

Briefly, depending on the mathematical convention used for standard state, the pKa for water is listed as either 14 or 15.7 and the pKa for hydronium is listed as either 0 or -1.74. When using the standard and agreed upon conventions of thermodynamics, the values of pKa are 14 and 0 for water and hydronium, respectively. Unfortunately, however, an overwhelming number of standard textbooks (introductory chemistry and organic chemistry) have relied upon using a non-standard convention that results in the values of 15.7 and -1.74. Depending on the article (and sometimes even the section of article), Wikipedia currently uses a combination of the values. I propose that we begin to clear up this issue by making the articles more consistent. This is a big undertaking since these values are likely to be found in a large number of individual articles. Furthermore, I would like to achieve at least some consensus among editors prior to taking this on. Thanks! JCMPC (talk) 16:57, 29 April 2018 (UTC)

Indeed, even Properties of water used to have 15.7 as the pH in the infobox until I changed it (among my early edits, actually) and why I put two references for the pKa and a note. Investigation into the history reveals that from ~2006 (basically when it was inserted), till 2016 when I changed it, it was 15.7, which is somewhat disturbing IMO. Anyhow, I'd definitely say that changing instances of 15.7 to 14 would be good to do. Galobtter (pingó mió) 17:27, 29 April 2018 (UTC)
I have a feeling that, until authors of organic chemistry textbooks switch to the standard thermodynamic convention, the value will likely be edited back and forth for some time on Wikipedia. Are any other editors willing to help out on making the switch to make articles more consistent? JCMPC (talk) 14:37, 5 May 2018 (UTC)
It looks to me like you guys are missing a factor in your argument. A standard convention does not reflect the real value of something. It is simply the chosen value for making empirical and theoretical coparrisons. For example, just because the IUPAC standard convension for ambient temperature and pressuren is 25 degrees Celcius and 100 kPa, does not mean that the location that you are in has those conditions. i.e. Just because some institution decides that the standard convension for the pKa water and hydronium is 0 and 14, does not make it so in reality. I strongly suggest that if you insist on retaining both sets of pKa values, that you make that non-standardised ones the primary set. Plasmic Physics (talk) 23:02, 5 May 2018 (UTC)
Yes, it is widely known that the definition of any standard state is arbitrary and is, in a great many cases, corresponds to an idealized value that is not even physically realizable (e.g. gaseous water does not exist at a partial pressure of 1 bar at a temperature of 300 K but we can still tabulate enthalpies of formation for water under those conditions). The advantage of using the widely accepted definition of thermodynamic standard states is not that these values are correct under all conditions (because they're not), but that they make it easier to communicate measurements and ideas. One of the main points of classical thermodynamics is to determine how factors such as pressure and temperature affect quantities such as equilibrium constants. As long as a standard value is known, it is possible to convert it to another set of conditions. So I guess I don't see the advantage to using non-standardized versions as the primary set of values. Wouldn't this be like supporting a non-standard definition of the meter? Sure one could always come up with a conversion factor to convert between standard and non-standard definitions of the meter, but why go through all the trouble when we can all just use the same definition? JCMPC (talk) 01:00, 17 May 2018 (UTC)
That is not a very accurate comparison - there is no notable use for a non-standard meter outside of discussions of the notion, whereas real, non-normalised pKas are useful to the entire field of analytical chemistry. It is simply not appropriate to use standard pKas within high precision fields. Furthermore, the ChemBox, as it is named, is first and foremost intended to collate chemical information before general thermodynamic information; and yes, I realise that there is some overlap, which is why I suggest the ordering of the pKas if both are included. Plasmic Physics (talk) 05:19, 17 May 2018 (UTC)

The value -1.76 is simply -log10(55.5) . It has nothing to do with acid dissociation. 55.5M is the molarity of pure water.

The criterion for classifying an acid as "strong" is that it is fully dissociated in solution. The following table shows the calculated degree of dissociation of a monobasic acid, AH, at a concentration of 1M, as a function of pKa. Dissociation will be greater, the lower the concentration of the acid.

pK % dissociation
1 27
0.5 43
0 62
-0.5 80
-1 92
-1.5 97
-2 99

This shows that, in general, an acid may be classified as "strong", if its pK value is less than about -2. That this value is close to -1.76 is purely fortuitous. Petergans (talk) 21:27, 13 August 2018 (UTC)

What is a metal in chemistry?[edit]

Is there a chemistry-based definition of a metal? I suspect not. If there was one I presume there would be no argh-bargy about where to draw the line of demarcation between metals and non metals, at least within the discipline of chemistry. Sandbh (talk) 07:57, 8 May 2018 (UTC)

There are several definitions, ranging from the simple (anything shiny and conductive) to the complex (unfilled electronic band at the fermi level). The problem, as your question points out, it in applying a binary ‘is/isn’t’ definition to what is in reality a gradient. Where you put the line is somewhat arbitrary (where does blue end and green begin?). In terms of Wikipedia, how/where is this a problem?--Project Osprey (talk) 08:54, 8 May 2018 (UTC)

Thank you.

I was interested in definitions based on chemical properties instead of physical properties such as shininess or conductivity. For example, simple cation formation or having at least one basic oxide. The challenge is that there are some metals like tantalum or tungsten that meet neither of these criteria. Just what is it, from a chemist's point of view, that warrants classifying Ta and W as metals?

There is not much of a gradient, as I understand it, in distinguishing between metals and nonmetals. The consensus of the literature classifies B, Si, Ge, As, Sb, and Te as metalloids. And Wikipedia classifies At as a metalloid, on the basis of its apparent properties, noting it has been predicted to have a fully metallic band structure. So, apart from H, elements to the left of the metalloids in the periodic table are metals.

The context for my question is a desire to improve our metal article. It seems odd that there does not seem to be an inclusive definition of a metal based purely on chemical properties. Sandbh (talk) 10:38, 9 May 2018 (UTC)


Metallic bonding[edit]

heading added Sandbh Sandbh (talk) 01:38, 12 May 2018 (UTC)
In that case I'd define a metal (somewhat cyclically) as anything which engages in metallic bonding. That is the chemical phenomenon behind most of their physical properties. Sadly the metallic bonding page needs quite a bit of work. --Project Osprey (talk) 10:58, 9 May 2018 (UTC)

That would be awkward since H is capable of forming alloy-like hydrides, featuring metallic bonding, with some transition metals. I'm not pretending this is an easy question—I don't yet see how to do it without including at least one physical property like conductivity. Sandbh (talk) 13:03, 9 May 2018 (UTC)

I don't think that's a strong argument. I imagine most elements can be alloyed but that doesn't mean that they're metallic in their own rights. Hydrogen is not a metal under standard conditions, that's obvious just by looking at it. That you can force it into displaying metallic properties is besides the point. --Project Osprey (talk) 13:31, 9 May 2018 (UTC)
Well, it seems like we'd have to add another criterion to the definition so as to exclude H, given it is capable of metallic bonding. You seem to be inferring that this would be a physical property like appearance. The only extra chemical property I can think of is to specify an ionisation energy less than or equal to that of mercury, but this also seems slightly circular. Sandbh (talk) 05:42, 10 May 2018 (UTC)
@Project Osprey: @Sandbh: I think the intent was to look at the pure element – which almost recreates our dividing line perfectly (if you add astatine as a metal), but excludes bismuth as α-Bi is isostructural to α-As and α-Sb. Double sharp (talk) 14:56, 9 May 2018 (UTC)
I have some reservations about relying on the wooly concept of a "metallic bond". That aside, the literature consensus is to treat Bi as a metal largely on the basis of its basic trioxide, the structure of which is also more like that of a typical metallic oxide unlike the molecular oxides of Sb and As. So, the definition would become something like, "In the periodic table, any element which (a) features a structure characterised by "metallic" bonding; or (b) has a basic oxide, is classified as a metal." Sandbh (talk) 12:08, 10 May 2018 (UTC)
I presume there is some notion of a standard temperature and pressure for this, because otherwise just about everything should be metallisable. But then at 0 °C and 1 bar (IUPAC standard temperature and pressure), α-Sn is the stable allotrope (which is certainly not characterised by metallic bonding), and both SnO and SnO2 are amphoteric. Double sharp (talk) 15:08, 10 May 2018 (UTC)
@Double sharp: Thank you. Yes, the definition I had in mind applies at IUPAC's SATP i.e. standard ambient temperature and pressure or 25 °C and 1 bar of pressure. I don't know, but I suspect SATP is more useful in considering the properties of the elements than STP given the complication caused by the reversion of white tin to grey tin at STP.
More importantly perhaps is the question of what we mean by a structure characterised by metallic bonding. Grey tin has the diamond structure but is also a semimetal in the physics based sense, even though it behaves like a semiconductor. As a semimetal there is presumably some vestige of metallic bonding. Then again, we can always say metallic bonding means "full value" metallic bonding therefore semimetals (physics) are not counted. In which case the suggested definition based on chemical properties would work. Sandbh (talk) 08:32, 11 May 2018 (UTC)
I'm confused now. Are we talking about 'metal' as in a state of matter (metallic state), or is this about metallic elements?--Project Osprey (talk) 09:05, 11 May 2018 (UTC)
@Project Osprey: Metallic elements. Sandbh (talk) 02:21, 12 May 2018 (UTC)
If we count semimetals, then carbon is a metal; if we exclude semimetals and demand basic oxides, then grey tin is not a metal while white tin is. I find the former distasteful for obvious reasons and the latter distasteful since there is no chemical change involved. Using cation formation leads to a more pleasant outcome; although I'm persuaded that this puts antimony on the metallic side, I don't find this problematic as it is electropositive enough to form compounds which can be considered salts. (I will have to look up germanium chemistry, though.) Double sharp (talk) 09:30, 11 May 2018 (UTC)

Sb3+ and Ge2+ cations[edit]

heading added Sandbh (talk) 08:46, 13 May 2018 (UTC)

The proposed definition of a metal applies at SATP. It does not matter if, at temperatures lower or higher than 25 °C, the metal in question becomes a semimetal, semiconductor, or an insulator. AFAIK there is no simple Sb3+ cation. The closest I have seen in the literature is [Sb(H2O)4(OH)2]+. The compound Sb8(GaCl4)2, which contains the homopolycation, Sb82+, was also prepared in 2004. The status of Sb "salts" was strongly criticised by Axiosaurus on the metalloid talk page. Evidence for the existence of a simple Sb cation, or a genuine Sb salt, appears to be lacking. Sandbh (talk) 12:40, 12 May 2018 (UTC)

@Sandbh: @Droog Andrey: (since I think these papers would interest both of you; incidentally, @Droog Andrey:, do you know where I could find those papers suggesting the existence of Sb3+ in perchloric acid media, since that's the way the standard reduction potential for Bi3+/Bi was measured?):
Here are some quotes on Sb3+:
"Other studies into the speciation of antimony(III) include one on the solubility of stibnite [Sb2N3] in HCl–NaCl solutions conducted by Ovchinnikov et al. (1983). Their data suggests that chloride complexing of trivalent antimony is unimportant in the temperature range 180 to 300°C (although these authors concluded differently). In sulfur free systems, antimony compounds hydrolize to form antimonous acid SbOH0
, which predominates over a wide range of pH. In the acid range, Sb(OH)+
is formed, and only at very high acidities is the free Sb3+ ion stable." (Ralf E. Krupp, 1988: "Solubility of stibnite in hydrogen sulfide solutions, speciation, and equilibrium constants, from 25 to 350°C"; 10.1016/0016-7037(88)90164-0)
"The accurate value of the standard potential of antimony against Sb3+ ions is not known since single Sb(III) ions exist in very small concentration in aqueous solution. Solubility determinations of Sb4O6 in HClO4 indicate [4, 5] that dissolved trivalent antimony is mainly in the form SbO+ (in the pH range 0 to 1)." (Past Vello's section on Sb in Standard Potentials in Aqueous Solution, 1985; this suggests to me that you need to go to negative pH to have a chance of seeing Sb3+).
Ab initio simulations support the existence of a Sb3+ aqua ion, although the above observations make it quite clear that you will not see any experimental evidence for it until the pH goes really low. See for example 10.1016/j.cplett.2011.05.060, which discusses Sb3+ along with the stable trivalent cations (Al3+, Fe3+, V3+, Ir3+, La3+, and Ce3+); I presume they are considering hydrolysis only from the metal cation itself, rather than from the acidity of the medium. The ion appears to have an interesting structure: "A completely different system is the main group ion Sb(III) with its lone electron pair destabilising the hydrate [38]. As this electron pair occupies a considerable space, it induces the formation of two different hydration hemispheres, one with four tightly bound ligands at a distance of 2.2 Å and another one on the opposite side with four much more loosely bound water molecules located 2.7 Å far from the ion. The latter are responsible for frequent exchanges between first and second hydration sphere, leading to an MRT value of 6 ps for first shell ligands and a very low MRT (< 2 ps) for those of the second shell, which is equally unsymmetric as the first shell, with 5 plus 8 ligands."; see 10.1021/ic901737y for more about this structure, which is due to the large space occupied by the 5s electron pair on Sb3+; Sn2+ has a similar issue. This is in stark contrast to As3+ which hydrolyses pretty much instantly; the article says "In the case of this smaller group V cation, the effect of the lone pair is apparently strong enough to cause an immediate hydrolysis, while in the heavier analogue Sb(III) it only leads to a strongly distorted hydration structure (vide supra)." Similar ions are Ge4+, Sn4+, and Pb4+ which hydrolyse on the picosecond scale. The final stable forms appear to be As(OH)2+ (there seems to be a typo in the article), Ge(OH)3(H2O)+, and hexacoordinate and heptacoordinate species of the form M(OH)+
for Sn and Pb respectively. (OTOH, Zr4+, Hf4+, Ce4+, and U4+ are confirmed to be real stable tetrapositive cations).
I will also add a word about Ge2+. It seems to be capable of existence (10.1002/jcc.21315) based on computational studies, and have a similarly distorted structure, again like Sn2+ and Sb3+ due to the lone pair. Given this, I think I might even dare to call germanium a metal as well as antimony. At least for the s- and p-block metals, it seems to be a sound criterion to demand aqueous cation formation; the d-block metals seem to require a somewhat different treatment. Double sharp (talk) 16:41, 12 May 2018 (UTC)

@Double sharp: @Droog Andrey: thank you Double sharp for those sources.

I now think too much significance is being attached to aqueous cation formation for As?, Sb, and Bi (and Ge). The species concerned seem to found only in highly acidic media, perhaps requiring negative pH in the case of Sb. I tend to be reminded of the claim that Hg was a transition metal based on the purported existence of Hg(IV) even though, as Jensen noted, the experimental conditions were quite extreme. In a similar vein, I'd regard the presence of Ge?, As?, Sb, and Bi aqueous cations as being too marginal to warrant classifying any of these elements as metals.

The original proposed definition stands up reasonably well i.e. "In the periodic table, any element which (a) features a structure characterised by "metallic" bonding; or (b) has a basic oxide, is classified as a metal." While Bi comprises covalently bonded atoms stacked in layers, its basic oxide is the starting point for most Bi chemisty. Sandbh (talk) 10:41, 13 May 2018 (UTC)

@Sandbh: Is Bi2O3 really completely basic, though? It's definitely more basic than Sb2O3, but Bi2O3 will dissolve in warm and very concentrated KOH.
Anyway, I don't agree that these species are irrelevant just because the unhydrolysed forms only occur at very low pH (except for As3+, which I agree does not exist as an aqua complex). Such a criterion would also exclude Pb2+, which doesn't even appear in the E–pH diagram for Pb species in The Aqueous Chemistry of the Elements even though it goes down to pH −1; Sn2+ is in a similar position, though it is called that in that book for simplicity. Yet I think we all would agree that tin and lead are metals. There does seem, however, to be a difference between elements that form and elements that don't form aqueous cations that is observable in chemistry: looking at Greenwood and Earnshaw, as well as 10.1002/jccs.196400020 for Ge(ClO4)2, it appears that GeII, GeIV, SbIII, BiIII, and PoIV form acidic oxoacid salts (with scare quotes possibly added), while AsIII, SeIV, and TeIV only form basic ones. Since Te also forms the Te(OH)3+ cation, simply relaxing the criterion to allow all incomplete hydroxy complexes doesn't seem to give the desired result (noting the dangers of this), since Te seems quite clearly to be closer to nonmetals than metals (it acts much like Se); requiring aqua cations to form seems better. We all have no hesitation talking about Tl3+, Sn2+, Pb2+, and Bi3+ even if those specific species rarely appear, because they are starting points of hydrolysis and they actually exist; why then should we not allow in Ge2+ and Sb3+? Double sharp (talk) 12:56, 13 May 2018 (UTC)
It should probably be noted that various nonmetals like iodine and sulfur can form what might be considered simple cations in some nonaqueous media. OrganoMetallurgy (talk) 13:12, 13 May 2018 (UTC)
P. B. Saxena has made some interesting comments about I+ and I3+ cations in pp. 112–118 of his Chemistry of Interhalogen Compounds (link). One argument he puts in support of his case is that many iodine compounds liberate iodine at the cathode when electrolysed in their molten or aqueous states, such as ICl, IBr, ICN, INO3, I2SO4, and so on. I must confess I'm not terribly convinced by some of this, though; for example, indeed ICl acts as a strong electrophilic iodinating reagent, but is a bare I+ cation really formed? BTW radon also forms simple Rn2+ cations in nonaqueous media; Greenwood and Earnshaw indeed mention cations of S, Se, Te, Cl, Br, and I formed in sufficiently oxidising solvents (e.g. oleum), but these are all polyatomic cations AFAIK, not like the simple cations of metals we were previously discussing. Double sharp (talk) 14:14, 13 May 2018 (UTC)
@Double sharp: That's not what I was referring to. Rather I'm talking about stuff like Bis(pyridine)iodonium(I) tetrafluoroborate which is essentially pyridine solvate a salt of the I+ cation and the sulfur compounds discussed this doi:10.1021/ic1012582 article. They may require ligands for stability, but so what? I think those sorts of compounds (and there are many other kinds I could mention if anyone's interested) have been rather artificially considered a separate class of compounds from metal complexes. OrganoMetallurgy (talk) 17:59, 13 May 2018 (UTC)
@OrganoMetallurgy: Oh, I see. Yes, I agree that the distinction is rather artificial. Please do mention some more; I'd be interested in seeing how many of the nonmetals can be roped into doing something like this! ^_^ Double sharp (talk) 23:43, 13 May 2018 (UTC)
@Double sharp: It seems that phosphorus, arsenic, antimony, and bismuth can all form bipyridine complexes doi:10.1039/C5SC02423D and sulfur, selenium, and tellurium form complexes with diiminopyridine doi:10.1021/ja9073968 and bromine and iodine both form bis pyridine complexes. --OrganoMetallurgy (talk) 22:34, 17 May 2018 (UTC)
@OrganoMetallurgy: Great, thank you so much for these examples! So in groups 15 through 17 only the strongest nonmetals N, O, F, and Cl remain unconquered in our lists so far. Double sharp (talk) 23:43, 17 May 2018 (UTC)

Anyway, I think the case of Sb(H2O)83+ is rather different from that of HgIV. The latter, if it exists at all, only appears in one compound at extreme conditions and does not illuminate anything else about Hg chemistry, which is resolutely that of a post-transition metal; so it is not terribly important for classification, unlike what is expected for Cn. But Sb3+ can be considered the starting point of hydrolysis that leads to Sb(H2O)4(OH)2+ and thence to Sb(OH)3; given that Sb has the ability to form "salts" formally involving a simple Sb3+ cation, like Bi, Po, and At but unlike As, Se, and Te (which only form basic salts), thinking of this cation as a starting point does seem to help understanding Sb chemistry even if it itself only appears at extreme conditions. I would say much the same of the cations Tl3+, Sn2+, Pb2+, Ce4+, Zr4+, and Hf4+. On the other hand, since As2O3 is a predominantly acidic oxide, and AsIII appears to quickly hydrolyse all the way to As(OH)3 (arsenious acid) in water, I would agree that thinking of As3+ is unhelpful.

When it comes down to it, all metals have a nonmetallic side (even caesium forms alkalides) and all nonmetals have a metallic side (even helium has a few similarities to beryllium), and especially around the metalloid line a binary distinction is difficult to maintain. We are not saying that antimony is wholly metallic or wholly nonmetallic; both statements are nonsense. To the extent that the question "is Sb a metal or not" makes sense, it must be asked in terms of which one gives a better first-order understanding of what one might expect of its physical and chemical properties. Since +3 is antimony's predominant oxidation state, in which Sb forms a cation and has an amphoteric oxide, I think it is less misleading to call it a metal with caveats than a nonmetal with caveats. The approach of looking at the most stable oxidation state in the p-block incidentally calls B, Si, Ge, As, and Te nonmetals, Sb a metal, and is agnostic on At given that At3+ has not yet been found AFAIK (although At+ and AtO+ being known suggests to me that it is a possibility). (Ge ends up on the nonmetal side because it forms a cation and has an amphoteric oxide in its unstable +2 oxidation state, and does neither in its stable +4 state.) Double sharp (talk) 06:04, 14 May 2018 (UTC)

Hmm, 10.1021/jp3099413 shows that even AtO+ is hydrolysed to AtOOH already around pH 2, so if At3+ does exist it must be at really low pH again. So I think I'd rather amend it to include all oxidation states found in species that actually appear on the element's E–pH diagram, so that astatine qualifies as a metal by virtue of the At+ cation. OTOH, Ge2+ would still not qualify germanium as one. Double sharp (talk) 08:28, 14 May 2018 (UTC)

@Double sharp: Earlier you wrote, "Is Bi2O3 really completely basic, though? It's definitely more basic than Sb2O3, but Bi2O3 will dissolve in warm and very concentrated KOH." In his Treatise on Inorganic Chemistry (1956 p. 677), Remy wrote, "The insolubility of bismuth oxide in dilute alkalis, as compared with the amphoteric oxides of arsenic and antimony, marks it out as being definitely a basic oxide." That seems to be the explanation then for regarding bismuth oxide as being basic. So, at this stage, the original proposed definition based on having "metallic" bonding or having a basic oxide appears to still hold. Sandbh (talk) 06:01, 15 May 2018 (UTC)

Apparent absence of chemical properties[edit]

heading added Sandbh Sandbh (talk) 01:50, 12 May 2018 (UTC)

────────────I would say that there isn't really any chemical properties that define metals. They do tend to have lower electronegativity than nonmetals, but there are exceptions. As far as I'm aware, in the context of chemistry, a metal is a element that in its pure form, under standard conditions, is considered metal ( elements that are considered metalloids are sometimes also included), based on its physical characteristics. Or alternatively to the electrical properties of a substance. OrganoMetallurgy (talk) 18:53, 11 May 2018 (UTC)

I was going to say I agreed with you as there were no chemical properties that appeared to be common to all metals. The fall back then becomes physical properties. However, I now tend to think that any element which…
  • can form a simple cation in aqueous solution; or
  • has a basic oxide; or
  • adopts multiple oxidation states differing by one, and forms coloured compounds…
merits being classified as a metal.
I could be wrong but I believe this chemistry-based definition covers all the elements commonly counted as metals. No need to invoke any physical properties (I suspect the coloured compound criterion could be dropped). Sandbh (talk) 12:32, 15 May 2018 (UTC)
And what if we think here in terms of 'if we take a piece of metal and we react it vs. if we take a piece of non-metal and we react it, do we know reactions that distinguish the metal from the non-metal (as in a non-true example: 'metals dissolve in acids under evolution of hydrogen, non-metals do not dissolve in acids under evolution of hydrogen' - noting that some metals do not dissolve in acids (in that way))? --Dirk Beetstra T C 13:04, 15 May 2018 (UTC)
Agreeing with Dirk, I wonder about where the above discussion is nudging toward. In my institution's inorganic courses, we don't dwell on defining a metal ion, transition metal (the Zn issue), a lanthanide (the lanthanum issue), a main group element (Zn again), a metalloid (gray vs red Se), an organometallic cmpd (is Mo(CO)6 organometallic?), etc. For bulk metals, we note that the electrical conductivity of metals follows a 1/T relationship whereas semiconductors go the other way. On the other hand for an encyclopedia, we gotta say something. I just recommend flexibility.--Smokefoot (talk) 13:46, 15 May 2018 (UTC)
I think that in practice, the real definition of a metal just depends on whatever is most convenient at the moment. For those elements on the borderlines, it may sometimes be useful to include them as metals, and sometimes useful to exclude them. It's just that when considering metals is not the main point, and we're still colouring elements by metallicity on a nice periodic table graphic in one corner or at the bottom, we need to pick some defaults, and they might as well be the least misleading defaults to the novice who takes those colours at face value. That does not in any way stop us from changing things around if the context makes it reasonable to do so, as you say. Double sharp (talk) 15:31, 15 May 2018 (UTC)
@Sandbh: Doesn't this definition classify chlorine as a metal if taken literally? Chlorine forms ClF3, ClO2, and ClF5, which have Cl in the +3, +4, and +5 states respectively (differing by one). ClO2 is a yellowish-green gas and hence meets the colour requirement. Double sharp (talk) 04:57, 16 May 2018 (UTC)
@Double sharp: Yes, it does—Headslap!—and I'm currently considering what to do about this. Any suggestions? Sandbh (talk) 11:13, 16 May 2018 (UTC)
10.1021/ed056p712 agrees with this pessimistic view, BTW. It suggests that metals can be distinguished by hardly ever assuming negative oxidation states, but we all know that gold means that this is not a criterion but a guideline. It also mentions that the metals become more nonmetallic in their properties as their oxidation state is increased (which is one reason for the very nonmetallic chemical behaviour of some of the 4d and 5d metals, for which the lower and more metallic oxidation states are unstable). It suggests high electrical conductivity in all three dimensions as a distinguishing physical property, but that approach would have us considering arsenic as a metal. Double sharp (talk) 15:28, 17 May 2018 (UTC)

Here's an update of the suggested definition of a metal, based on chemical properties:

Any element which…

* forms a simple cation in aqueous solution; or
* has a basic oxide; or
* uses d or f electrons in chemical bonding…

merits being classified as a metal.

Sandbh (talk) 10:25, 18 May 2018 (UTC)

@Sandbh: While I cannot think of anything that fails this definition at present that I think you can reasonably consider a metal, I dislike how it essentially rules the d- and f-block elements as metals by fiat (I guess adding the g-block elements once they are discovered). There must be something else that can be pointed to to support their metallicity. There are s-block metals and nonmetals, and p-block metals and nonmetals, so I have a hard time believing that block membership proves metallicity by itself. If it so happens that all d-block and f-block elements are metals (which I agree with), great, but I don't think we can declare it as a postulate. As Bertrand Russell wrote, "The method of 'postulating' what we want has many advantages; they are the same as the advantages of theft over honest toil." Double sharp (talk) 15:26, 22 May 2018 (UTC)

@Double sharp: The challenge is how to cater for metals that don't form simple cations namely Zr, Hf; Nb, Ta; W; Tc; and Os. The first four of these form interstitial (metallic) hydrides. The only suitable chemical property I can see for W, Tc and Os is their capacity to exist in more than eight integral oxidation states. So that would give:

Any element which…

* forms a simple cation in aqueous solution; or
* has a basic oxide; or
* forms an interstitial hydride; or
* can exist in more than eight integral oxidation states…

merits being classified as a metal.

The capacity to form an interstitial hydride, as I understand it, is partly related to the existence of a metallic lattice, so I'm OK with that criterion.

The capacity to exist in more than eight integral oxidation states is less satisfactory because it isn't immediately clear why it's associated with metallicity. Still, it's an improvement on the former definition. Thoughts? Sandbh (talk) 01:27, 1 July 2018 (UTC)

@Double sharp: After further thinking it's probably more helpful to flag the anomalies and note why the elements concerned are still regarded as metals. Like so:
Metal. An element which forms a simple cation in aqueous solution, or which has a basic oxide, or an interstitial hydride. Tungsten, technetium, and osmium exhibit none of these properties but are nevertheless classified as metals in light of their shared similarities with some other metals. These similarities include the capacity to exist in multiple oxidation states usually differing by 1, the formation of coloured solutions in water, and the formation of magnetic compounds. Sandbh (talk) 03:20, 21 July 2018 (UTC)

Metal article lede construction[edit]

heading added Sandbh (talk) 01:25, 12 May 2018 (UTC)

────────────One approach (which I think should be almost mandatory for most articles), is to build the lede on major (WP:TERTIARY) sources (not the damn OED). What are the "bibles" on metals? Get them and rely on them. As it stands, readers are force-fed these lame sources at the first five references:

  • 1) μέταλλον Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus Digital Library
  • 2) Oxford Dictionaries
  • 3) Encyclopædia Britannica
  • 4) John C. Martin. "What we learn from a star's metal content". New Analysis RR Lyrae Kinematics in the Solar Neighborhood. Retrieved September 7, 2005.
  • 5) BEC. "Physicists Achieve Early Stages of a New, Solid State of Hydrogen". Retrieved 7 January 2017.

--Smokefoot (talk) 13:50, 9 May 2018 (UTC)

The metal article is a challenge. AFAIK there is no global bible that deals with all aspects of metals. The subject seems to be so big that what bibles there are only (largely) deal with either the chemistry, structures, metallurgy, physics, or engineering aspects of metals. So, to some degree, one is forced to fall back on the most general of sources like the OED or Britannica in order to give the broadest possible description of a metal. Then drill down into the more specialised sources, like the lede currently does with astronomy. That aside, I do agree that even just the lede could be improved. Sandbh (talk) 01:25, 12 May 2018 (UTC)

Any love for Chromatography?[edit]

The Fundamental resolution equation article is in need of love and is on the same equation as the Purnell equation article. I hate tedious algebra (talk) 04:03, 16 July 2018 (UTC)

Acid strength definition[edit]

Buffer capacity for a 0.1 M aqueous solution of an acid with pKa of 7

Empirically, an acid can be said to be completely dissociated in solution when the concentration of molecules, HA, is below the detection limit for the species. There appear to be two, mutually incompatible, ways of quantifying what a strong acid is. See acid strength and acid dissociation constant for details.

  1. An acid with a pK value less than -1.76.This applies only to aqueous solutions
  2. An acid which is effectively 100% dissociated in solution

The first is the number -log10 55.5. 55.5 is the concentration/1M of H2O pure water. This seems to be the criterion commonly used for designating a compound as a superacid.

The second depends on the buffer capacity of the solvent, which rises very steeply with decreasing pH, starting at about pH 1 in aqueous solutions. This is independent of the pK value of the acid and is the cause of the solvent levelling effect.

What, if anything, should be done in WP about this contradictory state of affairs? Petergans (talk) 09:35, 19 July 2018 (UTC)

For the purposes of this does strong acid = superacid? Superacid is defined by IUPAC "A medium having a high acidity, generally greater than that of 100 wt.% sulfuric acid" which our current sulfuric acid chembox would indicate as being anything below a pka of -3 (?). If strong acid is something else, my first question is: is there a formal definition? I've always thought it a loose term (in my head anything with a pka <1 is strong). If no universal definition exists it's not our job to create one.--Project Osprey (talk) 08:39, 20 July 2018 (UTC)
@Project Osprey: Hi you are right in that a superacid has an acidity greater than 100% sulphuric acid or less than -12 on the Hammett acidity function. At this level of acidicity pH isn't really used anymore. EvilxFish (talk) 13:46, 20 July 2018 (UTC)

Facto Post – Issue 14 – 21 July 2018[edit]

Facto Post – Issue 14 – 21 July 2018
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Plugging the gaps – Wikimania report

Officially it is "bridging the gaps in knowledge", with Wikimania 2018 in Cape Town paying tribute to the southern African concept of ubuntu to implement it. Besides face-to-face interactions, Wikimedians do need their power sources.

Hackathon mentoring table wiring

Facto Post interviewed Jdforrester, who has attended every Wikimania, and now works as Senior Product Manager for the Wikimedia Foundation. His take on tackling the gaps in the Wikimedia movement is that "if we were an army, we could march in a column and close up all the gaps". In his view though, that is a faulty metaphor, and it leads to a completely false misunderstanding of the movement, its diversity and different aspirations, and the nature of the work as "fighting" to be done in the open sector. There are many fronts, and as an eventualist he feels the gaps experienced both by editors and by users of Wikimedia content are inevitable. He would like to see a greater emphasis on reuse of content, not simply its volume.

If that may not sound like radicalism, the Decolonizing the Internet conference here organized jointly with Whose Knowledge? can redress the picture. It comes with the claim to be "the first ever conference about centering marginalized knowledge online".

Plugbar buildup at the Hackathon

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Aromatic alcohol definition[edit]

I've found this problem checking Wikidata entries. I think you have an error in the definition of aromatic alcohol. The difference between aromatic alcohol and phenol is that in phenols hydroxy group is bonded directly to an aromatic ring (not neccesarily benzene ring) and in aromatic alcohols it is bonded indirectly (usually to the benzylic position). Right now definition in aromatic alcohol states that phenols = aromatic alcohols (however, Category:Aromatic alcohols says something different). Regards, Wostr (talk) 13:51, 21 July 2018 (UTC)

That is a substandard article that might be deleted. It is not supported by good references. It was created by a sockpuppet. I have no idea of the meaning of an "aromatic alcohol". Wikipedia has phenols, to which I propose to redirect aromatic alcohol, unless others disagree. BTW, phenols is in rough shape. It describes a large class of compounds.--Smokefoot (talk) 13:58, 21 July 2018 (UTC)
ChEBI defines "aromatic alcohol" as "Any alcohol in which the alcoholic hydroxy group is attached to a carbon which is itself bonded to an aromatic ring."[1] In my experience, this usage is not common ("benzylic alcohol" is clearer and less ambiguous vs phenol) and is also not the meaning used in our aromatic alcohol article (no requirement of the structural distance). The Manual of Scientific Style (I have no idea what standards-body is affiliated with this!) says "Aromatic alcohols (phenols) have the general formula Ar—OH."[2] and this usage seems to be present in the literature. But other sources clearly define phenols as being a disjoint set of hydroxyl functional group vs alcohols rather than a subset (IUPAC Gold Book specifically defines "alcohols" as OH attached to a saturated position). I think we are best with WP:TNT and writing a brief statement that the term is ambiguous, with pointers to the benzyl-alcohols and phenols articles. DMacks (talk) 20:46, 21 July 2018 (UTC)
Concur with TNT. --Smokefoot (talk) 23:33, 21 July 2018 (UTC)
Smokefoot redirected the title to phenols, which I think is the best thing to do for now. -- Ed (Edgar181) 13:24, 25 July 2018 (UTC)
No objection. I just did the same for Aromatic alcohols so that the plural and singular point to the same place. Would be interesting to scan WP for singular-vs-plural redirects that point to different targets, or where one is a redir to not-the-other. DMacks (talk) 13:42, 25 July 2018 (UTC)
@DMacks: That would be an interesting search. Maybe suggest it at Wikipedia talk:Database reports? -- Ed (Edgar181) 13:59, 25 July 2018 (UTC)
I posted at VPT (it also relates to a WP technical restriction). DMacks (talk) 14:10, 25 July 2018 (UTC)
Okay, thanks for solving this problem, but there is still Category:Aromatic alcohols. Wostr (talk) 20:26, 26 July 2018 (UTC)


I just started Nanodumbbell and have no idea what I'm doing. Please visit the article and see if the "Effect of Surfactant on Growth of ZnO Nanodumbbells..." external link is the right thing. Are these things silica or zinc or what? Many thanks! :) Anna Frodesiak (talk) 23:22, 24 July 2018 (UTC)

Usually one starts an article because we know our subject and we can demonstrate that the topic is notable. Notable usually means that the topic is featured in a book or a review article. But some good articles get started for strange reasons, and perhaps yours is an example of such. Probably however, if you have no idea what you are doing, the article is not worth writing.--Smokefoot (talk) 00:58, 25 July 2018 (UTC)
I agree it's kind of weird to start an article on a topic you don't know about :-) On the other hand, I've done a little searching and have convinced myself this is a reasonable topic for an article. Mostly I found research papers, but also some more general references, such as "Handbook of Less-Common Nanostructures". Google Books. Retrieved 2018-07-25. so I'm inclined to keep this and nurture it. -- RoySmith (talk) 13:49, 25 July 2018 (UTC)
It's the opposite axis as a molecular gyroscope. Rigid rotor is probably the parent article but that is already long and high-level/mathy, so this would not fit there (but should link back and forth) IMO. DMacks (talk) 14:30, 25 July 2018 (UTC)

Covalent bond or not ?[edit]

Curating data in WD I often have a problem with metal oxides where some representations show them as ionic compound and others as covalent molecules. See for example zirconyl nitrate:

  • Pubchem CID 11953300 with an ionic bond between oxygen and zirconium
  • Pubchem CID 11506893 with a covalent bond between oxygen and zirconium

These different structures have a strong impact on structural identifiers like InChI, InChIKey or SMILES.

Similar problem for complex like sodium hexacyanoferrate:

  • Chebi indicates covalent bonds between cyanide and iron giving OBOWFEZVRNRJBU-UHFFFAOYSA-N as InChIKey
  • Pubchem indicates ionic bonds giving GTSHREYGKSITGK-UHFFFAOYSA-N as InChIKey.

Is there any good reference or rule to define which structure is the better in order to define only one possibility as structural identifier ? Snipre (talk) 15:45, 25 July 2018 (UTC)

"Don't trust PubChem structures" is my first rule for...well almost anything. But especially for things with metals or complex 3D forms. For example consider ferrocene:
DMacks (talk) 15:57, 25 July 2018 (UTC)
For your first case, anhydrous zirconyl nitrate (what your two CIDs illustrate) might not even exist whereas several hydrates do.[4] But the structure of the pure hydrate seems to be a bridged polymeric chain and at least some zirconium–nitrate structures have bidentate nitrates.doi:10.1007/s11172-005-0222-7 And what the heck even is CID 83761? DMacks (talk) 16:16, 25 July 2018 (UTC)
Pubchem seems to be maintained for bio-organic chemists, so it is not reasonable to rely on that database for structures of metal compounds. But within English Wikipedia, we are pretty careful with structures. If you see any structures that are suspect, please leave a note here! Zirconium is a tough one, as DMacks suggests. --Smokefoot (talk) 16:25, 25 July 2018 (UTC)
@DMacks and Smokefoot: Thanks for your comment, but can you give me a better reference database ? Or any other references ? Snipre (talk) 12:37, 27 July 2018 (UTC)

In some ways it may not matter as neither SMILES or InChI can correctly represent anything other than fully organic compounds. If you follow the rules correctly salts and organometallics become 'Disconnected' to give you free metal ions and organic ligands. You do sometimes see people create accurate looking structures by playing around manually, but you often find that these 'hacked' SMILES or InChI strings give different outputs on different software (octahedral bonding can be particularly troublesome). --Project Osprey (talk) 13:43, 27 July 2018 (UTC)

Silicic acid[edit]

The AfD for Silicic acid was recently closed with a decision to keep, but the article itself could stand cleanup, I think. XOR'easter (talk) 15:33, 29 July 2018 (UTC)

OK, "silicic acid" was speedily deleted, which probably violates some policy or other about what to do with recently AfD'ed pages, but more importantly it makes the page history inaccessible. Silicic acid is now a redirect to silicon dioxide, and silicic acids is an article. XOR'easter (talk) 17:34, 1 August 2018 (UTC)
Could you check whether User:Galobtter managed to get everything back to the previous state? Silicic acid appears to be a full article with an extensive history (the only deleted revisions relate to page-moves and redirects) and Silicic acids is a redirect to it with no useful editorial history (nor anything in its deleted history). I could envision a good-faith discussion about whether the singular or plural should be the actual page-name for this apparent non-specific compound name. Is it in the realm of Wikipedia:Manual of Style/Chemistry/Compound classes or simply an ambiguous term? If it were to be plural, that doesn't automatically mean the singular should redirect to a different meaning (see WP:PRIMARY and WP:TWODABS). DMacks (talk) 18:07, 1 August 2018 (UTC)
Yeah I moved it back as it most likely shouldn't suddenly redirect to Silicon dioxide after 13 years of remaining an article, possibly breaking many of the links in and things like that (silicates may be a better target anyhow if one wanted to redirect it). Petergans - the information on the 2017 synthesis is good but probably should be integrated with the historical information in the previous version of Silicic acid.. Galobtter (pingó mió) 18:13, 1 August 2018 (UTC)
It looks like everything is in the right place — thank you very much! Whatever improvements need to be made now can probably happen through the day-to-day course of editing. XOR'easter (talk) 13:27, 2 August 2018 (UTC)


I noticed late last night that an anon added the hazards template to ethanol here, but inadvertently seems to have referenced and copied data from a calcium hydroxide reference "NIOSH Pocket Guide to Chemical Hazards #0092". National Institute for Occupational Safety and Health (NIOSH). for the PEL limits. I tagged it not in citation. Would someone please correct this error? Jim1138 (talk) 17:37, 29 July 2018 (UTC)

Often unsourced changes to NPAP 704 NFPA-H field[edit]

There are quite a few changes to teh NPAP 704 NPAP_h= field on the in ethanol, methanol (most common), and carbon dioxide articles. Sometimes deleting the source or referencing a photo. I often run across this while doing wp:RCP. What can be done to prevent this? Jim1138 (talk) 17:37, 29 July 2018 (UTC)

oxidized fats[edit]

I noticed this redirect oxidized fats, which points to a specific cardiovascular disease article. I find that this makes little sense, since there should be many topics for this particular term. Do we have an article on the oxidation of fat? -- (talk) 05:54, 31 July 2018 (UTC)

Rancidification? --Project Osprey (talk) 09:48, 31 July 2018 (UTC)
I've changed the target to that as being significantly better Galobtter (pingó mió) 18:15, 1 August 2018 (UTC)

Help requested re chemical formula subscripts[edit]

At Talk:Chemical formula § Subscript ambiguity I've asked for help regarding the possible ambiguity of subscripts. —[AlanM1(talk)]— 23:20, 31 July 2018 (UTC)

Nascent iodine[edit]

Someone might consider modifying the lede of Nascent iodine (dietary supplement) to indicate that the concept of nascency has been debunked. The problem is that the concept is so thoroughly debunked that if might be difficult to get a source. But for those naive readers wanting to read up on nascent iodine, we owe it to them to say that there is no such thing.--Smokefoot (talk) 02:11, 6 August 2018 (UTC)

Nascent state (chemistry) has some sources that look promising. Double sharp (talk) 02:16, 6 August 2018 (UTC)
 Done and thank you. --Smokefoot (talk) 00:21, 7 August 2018 (UTC)


Draft:Curaxins 2 is an Articles for Creation submission dealing with a family of anti-cancer molecules that needs attention from a subject matter expert. It would be great if someone could help out. Thanks! Catrìona (talk) 22:59, 6 August 2018 (UTC)


I've just finished a review of phosphoric acid. Once again, the clumsiness of the chembox is apparent. A large chembox like this one forces an editor to put pictures and tables on the left and generally leaves less space for the article text. What about mobile phone access?

Here is a suggestion: make all the categories collapsible, with "collapsed" as default setting, A chembox could look like this

Phosphoric acid (title)
Structures show
Names show
Identifiers show
Properties show

It will then be easy for a user to show a single category and view its contents, rather than having to trawl through a long list to find what he/she is looking for. Petergans (talk) 15:52, 12 August 2018 (UTC)

Making the boxes collapsible is reasonable and could certainly be helpful for the extremely full chemboxes. But those situations are the minority, so if the sections become collapsible, then uncollapsed should be the default state. -- Ed (Edgar181) 18:08, 12 August 2018 (UTC)
I'm not a fan of auto-collapsed tables as a rule. If it is better for mobile access then at least go with default un-collapsed on browsers and default collapsed on mobile view. --Project Osprey (talk) 19:25, 12 August 2018 (UTC)
Also, "collapsed" (i.e., by [show/hide] button) does not exist in mobile view. In mobile, it will allways show uncollapsed. This too is why one must design for 'uncollapsed'.
In a wider view: the desire to collapse an infobox has this inconsistency: if you want to collapse parts, that part does not qualify for a WP:INFOBOX. For {{Chembox}}, this contradiction stems from the habit to make the infobox into a data sheet as well. So it tries to square the circle: infobox = main info — datasheet = complete info. Personally, I think this could best be solved by moving minor data into a "Data sheet" section, leaving main info into in the infobox. Same with {{Infobox element}} and {{Infobox drug}}. -DePiep (talk) 12:20, 29 September 2018 (UTC)


I just created this. Feel free to expand/correct whatever I got wrong. Headbomb {t · c · p · b} 16:45, 17 August 2018 (UTC)

Unsourced NFPA 704 and hazards[edit]

Someone who geolocates to Kurgan, Kurgan Oblast, Russia is adding numerous unsourced {{Chembox Hazards}}. I opened a ticket on WP:ANI#Unsourced NFPA 704 and Chembox Hazards. If people wish to chime in, please do. Jim1138 (talk) 21:21, 17 August 2018 (UTC)

Carbon monoxide-releasing molecules[edit]

Carbon monoxide-releasing molecules is an article that I started a long time ago. It is a small area of research with potential clinical applications. Recently the article has been greatly expanded by a single highly focused author. It would be helpful if someone would help out because I cant go it alone and would just end up in an edit war over an article someone thinks they own.--Smokefoot (talk) 13:23, 18 August 2018 (UTC)

From the point of view of inorganic chemistry, I find nothing objectionable in the current text. The extensive use of very short sub-sections is not helpful. An important aspect, which I don't think was covered properly, is the absorption and release of CO by haemoglobin. This is particularly relevant to tobacco smokers. The key issue there is that the equilibrium constant for the reaction Hb-CO ⇌ Hb + CO strongly favours the CO complex, so the release of CO, even in someone who has stopped smoking, takes some time. (c.f. haemoglobin + cyanide) Petergans (talk) 18:58, 18 August 2018 (UTC)
excellent point. this is a problem for CORM therapeutics to overcome in the delivery of CO to a target. Hb is essentially an irreversible sink until the CO is exhaled. this will be added in the days ahead. Ketoacids (talk) 19:41, 19 August 2018 (UTC)

Seeking additional feedback to the recent expansion Ketoacids (talk) 13:25, 21 August 2018 (UTC)

As I have expressed previously, Carbon monoxide-releasing molecules is illustrates aspects of what Wikipedia should not be, IMHO. The guiding policy for citations are WP:SECONDARY and WP:TERTIARY. It is the kind of article that is promotional, almost fawning. The absence of a meaningful user page precludes perspective on the WP:COI issue. But Wikipedia is a big organism, and my dissatisfaction with this article is unimportant. --Smokefoot (talk) 13:47, 21 August 2018 (UTC)
Promotional? How so? The question is- does the new technical information provide a sufficient synopsis of the CORM field? If not, how can we make it better? Citation formatting is a concern we are working through. — Preceding unsigned comment added by Ketoacids (talkcontribs) 14:16, 21 August 2018 (UTC)
Who is this "we", Ketoacids? Galobtter (pingó mió) 14:20, 21 August 2018 (UTC)
you, me, Smokefoot, David notMD, Wikignomes, the various authors/editors of this topic- (not the 'royal we', incase you're a Lebowski fan). I am sensitive to the fact it is not my page. We are working together to make a better Chem Wiki.Ketoacids (talk) 14:35, 21 August 2018 (UTC)
It is your page. No experienced editor would create such a accumulation of specialized factoids and citations, which can seem cherry-picked. As of today, 598 patents, articles, reports describe CORMs, 108 of these citations have appeared since 2017 (SciFinder). Savvy editors dare not select among so many papers, lest we introduce bias (WP:UNDUE and WP:NOTNEWS). Instead, savvy editors kick back, Lebowski-style, and give an encyclopedic overview, citing a few reviews. My 2 cents. --Smokefoot (talk) 17:08, 21 August 2018 (UTC)

Template:Branches of chemistry[edit]

Hello. I work essentially in the Portuguese version of Wikipedia, which has serious problems in Chemistry related articles. I found one template which in my opinion is confused, and it's basically the same in English version. It's about Template:Branches of chemistry, which connects different areas in three main topics. I think it's a kind of arbitrary definition, some of that areas (eg Polymer chemistry, Physical organic chemistry, Pharmacy, Surface science, Geochemistry, Solid-state chemistry, Materials science, etc) are actually the result of mixing the three main topics (Physical, Inorganic and Organic Chemistry) with others scientific areas. I wonder if it wouldn't be better in a template such as in the Template:Branches of biology case, without these divisions. Att, Rafael Kenneth (talk) 20:46, 20 August 2018 (UTC)

Hey guys, no opinion? Isn't it possible to understand what I've said? Rafael Kenneth (talk) 04:10, 13 September 2018 (UTC)
Well I understand what you say, but I think that the organisation is OK. It is easier to see what is there than the more compact biology nav template. Graeme Bartlett (talk) 12:16, 13 September 2018 (UTC)

Facto Post – Issue 15 – 21 August 2018[edit]

Facto Post – Issue 15 – 21 August 2018
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Neglected diseases
Anti-parasitic drugs being distributed in Côte d'Ivoire
What's a Neglected Disease?, ScienceSource video

To grasp the nettle, there are rare diseases, there are tropical diseases and then there are "neglected diseases". Evidently a rare enough disease is likely to be neglected, but neglected disease these days means a disease not rare, but tropical, and most often infectious or parasitic. Rare diseases as a group are dominated, in contrast, by genetic diseases.

A major aspect of neglect is found in tracking drug discovery. Orphan drugs are those developed to treat rare diseases (rare enough not to have market-driven research), but there is some overlap in practice with the WHO's neglected diseases, where snakebite, a "neglected public health issue", is on the list.

From an encyclopedic point of view, lack of research also may mean lack of high-quality references: the core medical literature differs from primary research, since it operates by aggregating trials. This bibliographic deficit clearly hinders Wikipedia's mission. The ScienceSource project is currently addressing this issue, on Wikidata. Its Wikidata focus list at WD:SSFL is trying to ensure that neglect does not turn into bias in its selection of science papers.


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MediaWiki message delivery (talk) 13:23, 21 August 2018 (UTC)

Borane nomenclature[edit]

There is an issue with the titles of WP articles which are almost identical. The following are examples that I have picked up today. Where present, a number in parentheses indicates the number of hydrogen atoms.

Is this is issue covered by IUPAC rules on nomenclature? If not, I suggest that all article titles should indicate the number of hydrogen atoms. e.g. borane(3) instead of just borane. Any suggestions? Petergans (talk) 17:09, 24 August 2018 (UTC)

Before offering my suggestions, the community here owes you a big thank-you for cleaning up these articles. Borane in particular was filled with nutty and spurious verbage.
My suggestions:
Leave them alone. To me "borane" is completely unambiguous, even though there are many "boranes".
Leave them. Every chemist knows what "diborane" is. A famous species. The pair diborane(4) and diborane(2) of interest to a small handful of theoreticians. They have names that set them apart.
pentaborane should be pentaborane(9) for uniformity with the other B-H clusters and to distiguish it from things including pentaborane(11). Good catch.
Good catch, I converted hexaborane into a listing of hexaborane(10) and hexaborane(12). And created hexaborane(10).--Smokefoot (talk) 18:15, 24 August 2018 (UTC)
I fixed your hexaborane fix, as it was a Wikipedia:Cut and paste move (against Wikipedia policy and violates content-license terms) rather than a proper renaming. I also agree that diborane should remain as the specific B2H6 compound, as this is clearly the WP:PRIMARYTOPIC for this name. For others that are less-known, and cases where none are well-known, more specific names and a WP:DISAMBIGUATION at the simple name are good. Although CHEM and WP-wide MOS generally prescribe using singular for compound-classes, "boranes" is a good name for this class because "borane" itself is a definite specific chemical (this approach is equally supported by WP-wide MOS and CHEM apparent current practice). DMacks (talk) 21:49, 25 August 2018 (UTC)
@Petergans: please see the WP:HATNOTE regarding what is reasonable/unreasonable for {{see also}} entries. For example, someone going to diborane (about one specific chemical with this name) might reasonably be looking for a different chemical with this name that has a more-specifically-named article (diborane(2) or diborane(4)). But one would not likely be at the specific name diborane looking for the more general term of boranes or borane. They are certainly conceptually related and do/could/should link to each other. DMacks (talk) 22:05, 25 August 2018 (UTC)


The chromogen page may need improvement. The definition seems incomplete.

Currently, chromogen is defined as a precursor to a colored molecule.

I am more familiar with this definition:

"In simple terms, it can be considered that the organic dye molecules contained three main components such as chromogen, chromophore and auxochrome. • The chromogen is a chemical compound that is either colored or could be made colored by the attachment of suitable substituent. The chromophore and the auxochrome(s) are also part of the chromogen (Carmen and Daniela 2012). • The chromophore is a chemical group that is responsible for the appearance of color in compounds (the chromogen) where it is located. The colorants are sometimes also classified according to their main chromophore (e.g., azo dyes contain the chromophore –N=N–) (Iqbal 2008). • The auxochrome is a substituent group found in a chromogen that influences its color. Whereas, the chromophore or chromophoric group is responsible for chromogen which will be colored. The chromophore itself is not capable of determine a particular color and hue (Marsden 1982). Also, Gurr differentiates two types of auxochrome namely colligators, which are responsible for dye– substrate interactions and which are either ionic (e.g., acidic: –SO3 −, –COOH, etc., or basic: –N+, –NH2) or non-ionic and non-colligators which modify color (Burkinshaw 2016)."

Anyone agree/oppose to updating the page based on this reference? Ketoacids (talk) 12:47, 25 August 2018 (UTC)

Well, I repeat questions posed previously:
  • do you think that you can actually edit following WP:SECONDARY/WP:TERTIARY or is this revision going to be another literature cherry-picking campaign? Your record on Carbon monoxide-releasing molecules is unpromising.
  • Will you write a user page for yourself so that fellow editors can understand potential areas of expertise and COI?

--Smokefoot (talk) 14:19, 25 August 2018 (UTC)

I have reduced the page contents to a selection of definitions found in various dictionaries. Petergans (talk) 16:19, 2 September 2018 (UTC)

Draft:Spectroscopy of Multiply Ionized Atoms[edit]

A review of this draft is requested. Should it be accepted into article space? Robert McClenon (talk) 01:01, 28 August 2018 (UTC)

If there was an article on history of spectroscopy or multiply ionized atoms then the content would have a place to merge to, after trimming, but it is hardly suitable for a standalone topic - WP:COATRACK. Graeme Bartlett (talk) 12:08, 2 September 2018 (UTC)


FYI there is an RFC at Talk:Unbibium regarding whether a page at that title should now exist. shoy (reactions) 19:18, 24 September 2018 (UTC)

3DMet article: substance needed[edit]

I have created article stub 3DMet, since "3DMet" is used in {{Chembox}} (144x). An editor asked for more substance, since it does need some sourcing & notability notes. Pls take a look & an edit. -DePiep (talk) 07:28, 29 September 2018 (UTC)

ping Boleyn - DePiep (talk) 07:29, 29 September 2018 (UTC)
Maybe we could use a navbox re Chemical database (and Category:Chemical databases (47)). Or Chemical ID (identifiers only, Category:Chemical numbering schemes (43)); does this overlap with {{Authority control}}? -DePiep (talk) 11:36, 29 September 2018 (UTC)

Facto Post – Issue 16 – 30 September 2018[edit]

Facto Post – Issue 16 – 30 September 2018
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The science publishing landscape
So much to read, so less time.jpg

In an ideal world ... no, bear with your editor for just a minute ... there would be a format for scientific publishing online that was as much a standard as SI units are for the content. Likewise cataloguing publications would not be onerous, because part of the process would be to generate uniform metadata. Without claiming it could be the mythical free lunch, it might be reasonably be argued that sandwiches can be packaged much alike and have barcodes, whatever the fillings.

The best on offer, to stretch the metaphor, is the meal kit option, in the form of XML. Where scientific papers are delivered as XML downloads, you get all the ingredients ready to cook. But have to prepare the actual meal of slow food yourself. See Scholarly HTML for a recent pass at heading off XML with HTML, in other words in the native language of the Web.

The argument from real life is a traditional mixture of frictional forces, vested interests, and the classic irony of the principle of unripe time. On the other hand, discoverability actually diminishes with the prolific progress of science publishing. No, it really doesn't scale. Wikimedia as movement can do something in such cases. We know from open access, we grok the Web, we have our own horse in the HTML race, we have Wikidata and WikiJournal, and we have the chops to act.

Научные издания.jpg

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MediaWiki message delivery (talk) 17:57, 30 September 2018 (UTC)

Ternary compound and Tertiary (chemistry)[edit]

I've come across these sets of what seem to me like very similar articles: Ternary compound and Tertiary (chemistry), Quaternary compound and Quaternary (chemistry). Are these four distinct topics, or two topics unduly spread across four articles? And where does Quaternary phase fit into the picture? – Uanfala (talk) 09:27, 2 October 2018 (UTC)

Quaternary compound and Quaternary (chemistry) look to be the same topic. But Ternary compound and Tertiary (chemistry) are very different subjects. Graeme Bartlett (talk) 11:20, 2 October 2018 (UTC)
  • Quaternary phase is (sort of) the four-element equivalent of ternary compound (which deals with three elements) and binary compound (that deals with two elements). These deal with compounds based on the number of different elements in the compound. Quaternary phase, though, is more a materials science term.
  • Tertiary (chemistry) and quaternary (chemistry) are related terms in organic chemistry dealing with substitution patterns. Quaternary compound is a badly written article overlapping with quaternary (chemistry) and the two should probably be merged. The former seems to confuse a quaternary cation with an ionic compound containing a quaternary cation, and the latter deals with quaternary compounds whether the quaternary centre is cationic or neutral. EdChem (talk) 12:24, 2 October 2018 (UTC)


Hi. I just started an article about Alfred Wahlforss, who researched subtance called "bromtoluolklorid" in Swedish, "bromtoluolikloridi" in Finnish. I could not find the definite English term, but suppose that it is bromotoluene chloride. Is this correct? Many thanks, --Gwafton (talk) 19:43, 3 October 2018 (UTC)

I'd guess it's e.g. 4-bromo-3-chlorotoluene or any of its nine(?) other isomers. --Leyo 23:33, 3 October 2018 (UTC)
It's Br-C6H4-CH2Cl, I think para. This according to:
DMacks (talk) 02:13, 4 October 2018 (UTC)
You are right. BTW: ChemSpider, ECHA --Leyo 07:13, 4 October 2018 (UTC)
Sorry, my knowledge in chemistry is limited. So by what name shall I call the chemical in the article text? --Gwafton (talk) 18:53, 4 October 2018 (UTC)
Like most chemicals, there are several names in use. I would probably go with para-bromobenzyl chloride, as it makes clear that this is a derivative of benzyl chloride. Yilloslime (talk) 19:47, 4 October 2018 (UTC)
The article is now edited with the correct name. Many thanks for all who helped. --Gwafton (talk) 21:05, 4 October 2018 (UTC)
Thanks for working on it! Just for everyone's reference, Alfred Wahlforss is the article. DMacks (talk) 18:25, 5 October 2018 (UTC)

Donna Strickland, case study in ...[edit]

If anyone is interested in a real mess/fiasco/mistake/whatever, take a look at Talk:Donna Strickland for some expert handwringing,, wiki-lawyering, and shoulda-woulda. Apparently the article on this weeks's Nobelists Donna Strickland had been deleted as not notable. Of course that changed on Tuesday.--Smokefoot (talk) 12:31, 4 October 2018 (UTC)

Oh dear... that is a blazing PR disaster. Looks like the page was originally deleted for copyright infringement rather than notability. There was also a parallel draft which was declined due to lack of references. Obviously some confusion as to what's actually happened there - not that it matters now as its already hit the news.

Nomination of 3DMet for deletion[edit]

A discussion is taking place as to whether the article 3DMet is suitable for inclusion in Wikipedia according to Wikipedia's policies and guidelines or whether it should be deleted.

The article will be discussed at Wikipedia:Articles for deletion/3DMet until a consensus is reached, and anyone, including you, is welcome to contribute to the discussion. The nomination will explain the policies and guidelines which are of concern. The discussion focuses on high-quality evidence and our policies and guidelines.

Users may edit the article during the discussion, including to improve the article to address concerns raised in the discussion. However, do not remove the article-for-deletion notice from the top of the article.

Deletion of this artice would give {{Chembox}} a redlink in the lefthand side. DePiep (talk) 15:26, 15 October 2018 (UTC)