Template talk:Infobox element

Main isotopes
What is considered a main isotope or not ? cuz I have the intention of aligning French element boxes with english, but like for bismuth i saw 5 isotopes that extended until the last "one year or more" isotope (from 207 to 210m) which included an isotope (210) with a very low half life but i was like it still makes sense including what's inbetween but now i check Technetium and suddenly 7 isotopes are included (95m 96 97 97m 98 99 99m) instead of 3 on the french side (97 98 99) and none of the supplementary ones last very long (days or even hrs for 99m) Was the objective to include 99m (for its medical uses etc) and so you also included isotopes with longer half lives ? because like 99m Tc is 6hrs so you'd have to include 95Tc as well for it to make sense

tldr please give me the criteria for main isotopes TheÆtherPlayer (talk) 09:57, 5 January 2023 (UTC)


 * Good question. Let me kick off:
 * All stable isotopes
 * First isotope discovered
 * Isotopes in substantial medical use (Diagnostic radiopharmaceuticals, Therapeutic radiopharmaceuticals)
 * Isotopes in non-medical relevant usage (nuclear power, nuclear arms, ..)
 * Isotopes relevant in nuclear waste
 * Isotopes of other interest
 * When the number is high, say near 10–12(?), selection for "used" relevance etc. could be stronger.
 * Also, to search for clues. DePiep (talk) 11:50, 5 January 2023 (UTC)
 * I think the reasons that persuaded me in some cases where I edited the list of "main" isotopes are something like what the OP says. Sometimes there is an important short-lived isotope like 99mTc, and then it doesn't feel right to exclude longer-lived ones. For bismuth, I think it's a bit odd to include 210mBi without 210Bi. I don't think there's necessarily a need to include the first isotope discovered (in some cases nobody uses that for research today, e.g. 277Cn). Sometimes we don't include isotopes that are natural (e.g. 212Po which is too short-lived). In summary, I don't think there have been any strict criteria, and some editorial judgement can no doubt be used. Double sharp (talk) 14:14, 5 January 2023 (UTC)
 * I think for superheavy elements, just pick those isotopes that have longest half-lives. Also note that Template:Infobox lead isotopes and Template:Infobox lead have different list of isotopes. Nucleus hydro elemon (talk) 14:39, 5 January 2023 (UTC)
 * re your last remark: in a few days, we will merge those two lists (ie, will read ). Preview: Infobox uranium/sandbox. :-) DePiep (talk) 15:03, 5 January 2023 (UTC)
 * I generally agree with . I would consider a main isotope to meet any one of the following:
 * Primordial (stable or nearly stable)
 * Cosmogenic (these are generally fairly long-lived, and also include disputed primordial isotopes such as 244Pu)
 * Has medical uses
 * Common nuclear fuel sources and medium/long-lived fission products
 * For an element without at least 3–5 isotopes satisfying the above (including SHEs), include the longest-lived remaining isotopes. I too would say these aren't strict criteria, and also feel that a gap in half-lives spanning several orders of magnitude (such as 10 days to 50 years for isotopes of platinum) is usually a good cutting point, as is the notion of "include the shortest-lived useful isotope and everything longer-lived". Also agree with that short-lived isotopes, even if occurring on earth or in stars, are not always worth including (such as 8Be, 52Fe, 212Po).  Complex / Rational  20:26, 5 January 2023 (UTC)
 * I'd object to ".. [if not 5, then] include the longest-lived remaining isotopes". It says "Main", not "Most interesting": listing requires at least some external (non-element-inside) relevance. IF only 3? So be it. Criteria are good if an outsider can understand & apply them, but extra "because of half-life" is arbitrary. Same for "shortest-lived useful isotope and everything longer-lived": relevance for such selection, by half-life-range only & explicitly, is not explicable.
 * TL;DR: IOW, only use the 'outside relevance' criteria, as listed. DePiep (talk) 22:00, 5 January 2023 (UTC)
 * Also, don't forget that non/lesser-main isotopes can be described/discussed in both the Article and in its Isotopes of .. article bodies. DePiep (talk) 22:02, 5 January 2023 (UTC)
 * Very true. The last point was more pertinent for superheavy elements or monoisotopic elements without useful/cosmogenic radioisotopes (for instance, rhodium), and I'd add a new 'outside relevance' criterion (which I forgot earlier) of a nuclide that is confirmed to be an extinct radionuclide – this catches some of the long-lived ones that have gotten non-trivial attention in the literature and are of interest to geologists. Complex / Rational  01:07, 6 January 2023 (UTC)
 * For rhodium as a case study, 103Rh is stable and 105Rh is a fission product that's also interesting as a radiopharmaceutical. The latter is not the most stable radioisotope, but the more stable ones have the problem of being on the proton-rich side, hence harder to make and of lesser interest. In this case I do think that "half-life" and "main" are somewhat at odds. However, for most elements they are quite correlated, so perhaps it is a lesser evil to put in one or two questionably "main" isotopes to avoid giving the reader the wrong idea. But in that case, perhaps it should become "longest-lived" isotopes to have some objectivity. I'm not really sure yet what to do in a case like this one. Double sharp (talk) 02:49, 6 January 2023 (UTC)
 * I think we don't need to mention isotopes that are more stable but have lesser interest. #Isotopes section exists, just mention them there. Nucleus hydro elemon (talk) 04:02, 6 January 2023 (UTC)
 * Complex/Rational, do I understand you've added #5
 * CR 5. Confirmed to be an extinct ... of geologic interest
 * then? Sounds hulpful, assuming it is limited in numbers of isotopes involved. We should keep in mind that it is an explicit purpose of this list to exclude (possibly) trivial isotopes. DePiep (talk) 20:20, 6 January 2023 (UTC)
 * Thanks to everyone for the answers, I'll try to apply that as best as I can. TheÆtherPlayer (talk) 08:48, 9 January 2023 (UTC)


 * So far: TL;DR: Next from the workable numbered criteria given, the criteria in prose here are not useful. So either we ditch unqualifying isotopes from "Main isotopes", or we rewrite those verbose criteria them into objective ones. Goal is a MOS.


 * I'm still not happy with the result so far. I assume we can flesh out the crisp criteria mentioned, say DePiep DP 1–5 or ComplexRational CR 1–5. These are positive inclusions, all fine.
 * But what with the other half-life reasonings here? To me, they are opaque or not actually establishing a "Being Main" reason.
 * Together, we at enwiki could end up ditching a 33%(?) of all the Main Isotopes listed (see ).
 * While, the criteria should end up in MOS:PERIODICTABLE.


 * So: either we establish objective criteria for those half-lives not covered by 1–5 or we'll ditch those isotopes failing (20%?–40%?). -DePiep (talk) 09:18, 9 January 2023 (UTC)
 * After thinking about it, I support adopting CR's criteria 1–5, and ditching all isotopes failing them. Sorry that the thinking took some days. Double sharp (talk) 16:08, 9 January 2023 (UTC)
 * OK, thanks, we'll go to WT:ELEM then and flesh them out into some crispy 5. Removal best & easiest after having a MOS. DePiep (talk) 18:31, 9 January 2023 (UTC)
 * Agreed. My apologize for not responding sooner, but what I wrote is in essence a fifth criterion. The only open question then is what to do about elements that have only one or two (or even zero) isotopes covered by these criteria, such as SHEs. Complex / Rational  18:47, 9 January 2023 (UTC)
 * All is fine. (quick reply: adding "WP:IAR" rule). Pls see . DePiep (talk) 07:45, 10 January 2023 (UTC)


 * Continued at WP:ELEMENTS: This discussion continues at, to reach stable MOS lines.
 * Please do not extend the talk here. -DePiep (talk) 19:58, 9 January 2023 (UTC)

First improvement: use new parameter "main"
(editors here):

From now on: use reason for inclusion when adding an isotope to the list ("Main isotopes").

This input text does not show, but is useful for editors maintaining this list (and ultimately, remove/keep isotopes as "Main").

Please consider as obligatory/MOS/good editing habit.
 * -DePiep (talk) 11:35, 9 January 2023 (UTC) (fixed sec title, reping -11:41, 9 January 2023 (UTC))

Standard atomic weight: style change
I have changed the style (presentation) of the s.a.w. (for stable elements only then, not mass number). It now has a boxwide line for the quantity (=label, LH-side). Before, the Ar text was squeezed into the LH labelcolumn, which looked bad especially in mobile view (3-line label). Technically, s.a.w. now is a child infobox. In Infobox element isotopes, a similar change applied. DePiep (talk) 10:36, 11 January 2023 (UTC)


 * Ideas are welcome to improve texts, it is a difficult value to explain. For example, the name "weight" is archaic and incorrect, and people easily expect a unit (would be Da). DePiep (talk) 11:08, 11 January 2023 (UTC)

Lattice constant
Hi all, there have been a couple requests at Template talk:Infobox gold to add the lattice constant. I don't have a ton of subject knowledge here: is that a reasonable thing to add to this? If so, I can throw something together in the sandbox. LittlePuppers (talk) 02:50, 14 January 2024 (UTC)