Talk:Beta-decay stable isobars

I stopped transforming the list of beta-stable nuclides because I first like to hear other people oppinion to this kind of presentation and I'm not quite lucky with my form. Else I type in this table and then I must layout it completely different, because others have better ideas.

At the moment, it is unclear to people who do not know the subject, what this is about! It would very much help if you put explanation in along with the table you are presenting. Quantpole (talk) 22:58, 18 June 2009 (UTC)

Thanks for your helpful want-to-be hand. :) I wrote just a very bad introduction, but hopefully give the most important informations. Regards. —Preceding unsigned comment added by Achim1999 (talk • contribs) 11:31, 19 June 2009 (UTC)

For current bad reasons: I just was forced two times bei Abce2 and previous by L... (see history of the article-page) to restore the page main contens because they simple deleted most of information I added. If such behaviour stays I will no longer build up this page! Or you must give me exclusive write-acces to prevent such vandalism. Regards! —Preceding unsigned comment added by Achim1999 (talk • contribs) 14:17, 19 June 2009 (UTC)

Known Line of beta-stability finally converted completely into list of nuclides. :) Better to replace (@) in this list resp. table by colored nuclide-symbols to get this table a bit narrower? Achim1999 (talk) 14:07, 21 June 2009 (UTC)

Decays contrary to table in this article?
--JWB (talk) 02:43, 6 August 2009 (UTC)

What is your problem respectively question? Regards, Achim1999 (talk) 11:21, 6 August 2009 (UTC)

In these 4 rows, what you have marked as the most beta-stable isobar of that mass, is different from what you would expect based on the direction of beta decay of adjacent isobars. --JWB (talk) 19:53, 6 August 2009 (UTC)

These 4 rows are yours! They are not from the article (-- I wonder about the use of your first column in this relation). I suggest you first read CAREFULLY what is stated in the article. :) E.g.: It is stated that for A=36 there are 2 beta-stable nuclides, namely 36S and 36Ar. Moreover the last is in italic because it may transform with double-beta decay or double e–-capture into sulfur-36. BTW: Your wording "most beta-stable" seems to be your invention. :) Regards, Achim1999 (talk) 21:35, 6 August 2009 (UTC)

Is "Beta-decay stable" from a source? I see 461 Google hits but they appear to be Wikipedia mirrors. If the term is your own, see WP:Neologism.

I can think of several possible meanings for "beta-decay stable":

1) Not observed to beta decay

2) Not predicted to beta decay by specific theory

3) Lowest-mass isobar for this mass number (this is what you seem to be using)

4) Direction of beta decays of other isobars of this mass number all point towards this isobar, i.e. lower-Z isobars beta-minus decay and higher-Z isobars beta-plus decay or electron capture. (this is what I used in my chart cited above)

If you are going to stick to only your definition, it would be clearer to call it something like List of lightest isobars by mass number.

If you are going to stick to a term like "beta-decay stable", you should discuss the possible meanings of the term, since people may assume various ones.

Also, the fact that 3) and 4) are opposite for the 4 cases above is interesting and would be a good point to discuss in this or another Wikipedia article. I do not have an explanation for this, do you?

--JWB (talk) 22:17, 6 August 2009 (UTC)

"beta-decay stable" seems to be a short-hand for "stable against beta-decay", i.e. unable to decay by (simple) beta(+/-) -decay. —Preceding unsigned comment added by 93.207.6.220 (talk) 21:21, 9 August 2009 (UTC)

Number "136"
The number "136" has only 2 beta-decay-stable nuclides---The nuclide "Xn-136" is unstable! — Preceding unsigned comment added by 59.126.202.81 (talk) 14:49, 4 July 2012 (UTC)

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The Russian prediction (linked) for the continuation of the line of beta stability to the superheavy region
I would prefer something more recent, though. (Fairly obviously, all these nuclei must undergo &alpha; decay or spontaneous fission. Decay modes are from, correcting the original old Russian source if necessary. Unfortunately, that chart of predictions stops at N = 189.) Double sharp (talk) 09:17, 7 November 2016 (UTC)
 * It might be salutary to remark that despite the great difficulties of getting enough neutrons into superheavy nuclides via fusion-evaporation reactions, we have somehow managed to heroically follow the line of beta stability until Ds, element 110. (We know of 262No, 266Lr, 270Rf, 270Db, 271Sg, 278Bh, 277Hs, 282Mt, and 280Ds.) Double sharp (talk) 13:58, 11 April 2017 (UTC)
 * Oh, I found a chart of decay modes going beyond N = 189; updated. We may also have found 286Cn! Double sharp (talk) 14:11, 27 May 2017 (UTC)
 * P.S. That chart going just beyond N = 200 is from Karpov, Zagrebaev et al. as well: . The "failure" at Nh is clearly visible. Double sharp (talk) 11:56, 29 December 2023 (UTC)
 * Wow, glad to know that some source has explicitly predicted the third element with no beta stable isotope (Z = 113) and the next even neutron numbers with only two beta stable isotopes (N = 176 and 180)! Also, judging from the trend of the table, the energy difference between 288Ds and 288Cn as well as 294Cn and 294Fl must be very small (like the case of 98Mo and 98Ru as well as 146Nd and 146Sm). 129.104.241.214 (talk) 23:12, 27 December 2023 (UTC)
 * Actually this is not so much a reliable source as a synthesis of two. :) I think I compiled this six and a half years ago based on updating the external link on the article with Zagrebaev et al.'s data. It is nonetheless pretty much as you say regarding the explicit prediction for Z = 113: in Zagrebaev et al.'s chart, every Nh isotope near the expected beta-stable valley suffers either β+ or β−. But KTUY model disagrees and claims 295,297Nh should be beta-stable: you may view their predictions here. Well, for Tc and Pm it is also a close thing. :)
 * I also realise I made a mistake for mass 281. The old source gives it to 281Mt, but Zagrebaev et al. give it a small β+ branch. Corrected to 281Hs: the only beta-stable isotope for Mt should be 283. So N = 172 also has only two (280Hs and 282Ds). That makes 282 another anomaly like 288 and 294, which perhaps suggests that this exercise of reconciling two sources ought to be taken with some pinches of salt. :)
 * Differences where Zagrebaev et al. differ from the old source: 269 (old source says 269Rf beta-stable, but Zagrebaev et al. predict β−); 273 (old source must have a typo, it lists this mass for both Db and Sg; I assigned it to Sg because three beta-stable nuclides for odd Z seem implausible); 283 (old source predicts 283Ds, but Zagrebaev et al. predict β+, so is probably Mt); 287 (old source predicts 287Rg, Zagrebaev et al. predict β+); 289 (old source predicts 289Cn; Zagrebaev et al. appear to assign it to 289Rg as only beta-stable); 293 (old source gives it to 293Nh, but Zagrebaev et al. say it has no beta-stable isotope). So the 288 and 294 anomalies you mention might be a result of this being a synthesis of two sources – although who knows, similar things have happened within known nuclides as you also say. Though maybe 294 is real if Nh really has no beta-stable isotopes, since the examples you give are both surrounding an element where this disaster happens (Tc and Pm)? But as you can see, they're mostly in agreement along this range, which is why I thought the exercise to reconcile them was worth trying. :) Double sharp (talk) 12:59, 28 December 2023 (UTC)
 * P.S. since Zagrebaev et al. do not consider double-beta IIRC (it's only a thing in the old source, where double-beta-unstable nuclides are written smaller), I decided to use some common sense and edit the double-beta directions for 282 and 288 above in this exercise. I'm leaving 294, since either way it will be an anomaly and this way it keeps consistency with the similar failures at Tc and Pm (and now Nh I guess). Double sharp (talk) 17:12, 29 December 2023 (UTC)
 * In short: assuming that Lr and Mt each have a beta-stable isotope and thay Sg, Bh and Hs each have at most two odd-mass beta-stable isotopes, Zagrebaev et al.'s prediction gives the odd-mass beta-stable nuclides as 259,261Md, 263No, 265Lr, 267Rf, 269Db, 271Db/Sg, 273Sg, 275Sg/Bh, 277Bh, 279Bh/Hs, 281Hs, 283Mt, 285,287Ds, 289Rg, 291,293Cn, 295,297Fl. Personally I would expect 271Db and 279Hs to be beta-stable, and that 275Sg and 275Bh are close in energy. 129.104.241.214 (talk) 23:36, 7 January 2024 (UTC)
 * Just a remark: I believe that 48Ca, 96Zr and 148Gd should not be shown in this table :) 129.104.241.214 (talk) 23:41, 27 December 2023 (UTC)
 * Done as you asked. I hadn't updated this one since it's only on the talk page. :) Double sharp (talk) 12:54, 28 December 2023 (UTC)

You know what, I may as well give the KTUY chart for this region too. Sorry for pasting it from your sandbox. :) It goes on past that, but I stopped it at the known elements because it then starts predicting weirdness that never happened before (e.g. quadruple beta decay without double beta decay at mass 344). Oh well, extrapolation is perilous anyway. :) To add on to these comments incidentally: that's a whole lot of neutron-rich nuclides for Z = 114. I guess Dy is similar on the proton-rich side, but with one fewer. Perhaps this assumes 114 is a magic number? In which case I would take this with a grain of salt since experiments suggest it might not be one. Double sharp (talk) 13:22, 28 December 2023 (UTC)
 * P.S. Just realised from the chart that KTUY fails to predict the failures at Tc and Pm. Double sharp (talk) 11:51, 29 December 2023 (UTC)
 * Somewhere on the Internet I have seen a prediction that differs from the table above (not KTUY, but the other one) for 268 (Rf and Sg), 274 (Rf, Sg, Hs), 278 (Sg and Hs), 280 (Sg and Hs), 283 (Hs), 284 (Hs and Ds), 286 (Hs and Ds), 290 (Ds and Cn), 296 (Cn and Fl), 298 (Fl), 301 (Mc), 302 (Fl and Lv), 303 (Mc), 304 (Fl, Lv, Og), 305 (Lv), and 307 (Ts). I've forgotten the URL, though. AFAIR it was in a PDF file of some Italian conference. Burzuchius (talk) 19:42, 29 December 2023 (UTC)
 * I hope you find the URL again someday! Did it go beyond 312? It's interesting that the failure at Nh is reproduced by another model, although three beta-stable isotopes of Mc (299, 301, 303) would certainly be unprecedented for an odd element. Double sharp (talk) 20:49, 29 December 2023 (UTC)
 * AFAIR the last nuclide in the chart was 308Og. Burzuchius (talk) 21:17, 29 December 2023 (UTC)
 * Wow, this prediction would imply that Sg (268, 270, 272-276, 278, 280), Hs (276, 278-284, 286), Fl (292, 294-298, 300, 302, 304) each have 9 beta-stable isotopes, and Mt has none? 129.104.241.214 (talk) 02:33, 6 January 2024 (UTC)
 * I would say that adding two more lines (up to 336) introduces not too many strange things; it becomes a disaster from 342128 on. 129.104.241.214 (talk) 22:36, 7 January 2024 (UTC)
 * I noticed the KTUV chart predicting great instability of superheavy nuclides except for those around the doubly-magic nuclides. The page "Total half-lives" indicates that all beta-stable isotopes of elements 119-125, 137-145 lie outside the area of stability. What a pity. 129.104.241.214 (talk) 06:38, 10 January 2024 (UTC)
 * A pity indeed, but not unexpected once the N = 184 shell closure is passed. Double sharp (talk) 15:29, 11 January 2024 (UTC)

Undiscovered isotopes listed
Some undiscovered isotopes such as 261No and 269Db are listed in the table and other mass numbers such as A = 262 may have some undiscovered beta-stable isotopes. There are some we already know of, such as 259Md and 262No, but that is certainly not the entire data set up to A = 270. As far as predictions, various sources (see below) do not completely agree on one set of beta-stable nuclides; thus, I feel the inclusion of unknown isotopes is speculative and not merited (or there may be no reason to stop at 270 if predictions may be included).

Sources:

ComplexRational (talk) 19:54, 22 November 2018 (UTC)


 * Also, because of this inconsistency, should we remove snippets such as "287Rg will be most stable against beta-decay" (in fact, neither source above predicts 287 in this case anyway) from SHE articles? ComplexRational (talk) 20:05, 22 November 2018 (UTC)


 * I have no problem with inserting predictions, as long as it is made clear that they are, in fact, predictions. A separate table seems like a good idea. I would agree with removing those snippets from the superheavy element articles. Double sharp (talk) 02:36, 3 December 2018 (UTC)


 * I actually did draft a table in one of my sandboxes based on the third link I provided above. Though it does not match as well with the known beta-stability line as the Moller mass table, the latter one exhibits some unusual properties before A = 300 and contradicts some statements made earlier in the article. The one I drafted could supposedly also go beyond A = 340, though the same problem appears (e.g. it lists four beta-stable isotopes of E127 including one odd-odd and two beta-stable isobars with some odd A). As for the other articles, I will go ahead and remove them, especially since three sources give three different beta-stability lines. ComplexRational (talk) 23:37, 3 December 2018 (UTC)
 * ✅ as proposed for 109-111 (though it appears problematic in recent changes, why is that?) ComplexRational (talk) 23:43, 3 December 2018 (UTC)
 * I don't think it is that much of an issue that the unusual properties appear after A = 340. After all, we have never gotten anywhere near that mass number. If weird nuclear shapes are expected in that region, why not weird beta-stability lines? ^_^ And I should like to at least reach the double-magic nucleus 354126. Double sharp (talk) 03:11, 4 December 2018 (UTC)
 * Well, I've extended your table as far as it could go (I hope I haven't made any silly mistakes transcribing it). I do agree that most of it shouldn't go in the article because the predictions differ and all contain some weirdness, but I think a general discussion of where the beta stability line is likely to go beyond what we know would be germane, along with a brief mention that weird things happen eventually in all models (perhaps displaying things up to the doubly-magic 354126 would serve as a good enough illustration of what kind of weirdness we mean). So we could upload one of the charts from the presentations, and then noting that 298Fl, 354126, 472164, 616210, and 798274 ought to be doubly-magic beta-stable nuclides. I'd also be OK with just cutting things down to A = 340 and then adding this general discussion; after all, while the details differ, there seems to be agreement on the general location of the beta-stability line. Double sharp (talk) 04:58, 4 December 2018 (UTC)
 * Displaying up to 354126 is a good idea, though I'm unsure how to explain, for example, how A = 347, 349 have two beta-stable nuclides even though the article says (albeit briefly) that only one beta-stable nuclide can exist for odd A, and the unusual situation for A = 348 (triple beta decay, how might the two isotopes in between behave?) that contradicts the concept of "mass parabolas" outlined in various sources. That's far from the worst, thankfully. I also feel that uploading the decay mode chart up to Z = 149 and N = 256, both charts up to Z = 175, and the two images showing the shell gaps for proton and neutron numbers would provide some much needed illustrations in this and other articles. I'm not entirely sure about copyrights, though one of the images (the first one) already pops up in a Google search. Would you be able to assist me in navigating copyright rules? ComplexRational (talk) 01:46, 5 December 2018 (UTC)
 * I would think that the copyright status would be rather like that of File:Island of Stability derived from Zagrebaev.png; as it is data graphed in the most obvious way possible (a chart of nuclides), it isn't eligible for copyright. Thanks for adding the info up to A = 404, BTW; I'd like to know where you found that, as I missed it looking through the slides! (472164 is also labelled rather badly in the slides, as the line pointing to it seems to end at 470162 instead.) I wonder if all of this strangeness is because of the nearby doubly-magic 354126 nuclide that the beta stability line seems to be a bit distorted around (it is on the extreme neutron-rich end of the beta-stability line; in fact it looks something like a much more extreme 48Ca); the parabolas may well not look very much like parabolas around there. (Note that the line seems to look much more normal around 472164, though, so this bit of OR speculation may be completely wrong.) BTW, neutrinoless quadruple beta decay has been suggested as a possible decay mode (and it has even been searched for in 150Nd, although the half-life should be incredibly long), so I'm prepared for more exotica. ^_^ Double sharp (talk) 04:55, 5 December 2018 (UTC)
 * The chart on page 13 goes up to Z = 149 and N = 256. That type of explanation (and a citation of the quadruple beta decay paper possibly elsewhere as well) should work fine. I think you are right about the copyrights for the basic charts (simple geometric shapes), but I do not know about the one with the shell gaps. ComplexRational (talk) 00:23, 6 December 2018 (UTC)
 * I think that one would have the same copyright status as File:Next proton shell.svg (i.e. common-property information; graphing shells by energy and pointing to gaps is also the most obvious way to show this information). Double sharp (talk) 13:13, 7 December 2018 (UTC)

I uploaded one image, File:Nuclear chart from KTUY model.png; it meets the same criteria as File:Superheavy decay modes predicted.png. However, I'm still unsure about its inclusion and how to explain it without appearing to favor this source over other predictions. ComplexRational (talk) 00:03, 16 January 2019 (UTC)

Use of the term isobar in the title
Perhaps this is a stupid question, but is isobar the best term to be using in the title in contrast to nuclide or having the title line of beta stability (mentioned as an alternative in the lead)? I understand the significance of isobars in the collective beta decay processes, and it would make sense to consider a set of isobars with a given mass number as one example of finding the corresponding stable nuclide(s) in the valley of stability. But does it still make sense in the context of all beta-stable nuclides? Not only do these nuclides not have the same mass number, but in most cases the mass number is unique in the set. If it is an appropriate term, are there reliable sources that use the term in that context? StuartH (talk) 04:17, 20 January 2023 (UTC)
 * Also, there may be room to mention the Mattauch isobar rule given we are talking about beta decay in the context of isobars. I was trying to remember the name of the rule and thought this might be a good article to include it. StuartH (talk) 05:33, 20 January 2023 (UTC)

Non-observed beta decays
"Non-primordial 247Cm should undergo beta decay to 247Bk, but has also never been observed to do so." Why is this an important fact? This applies also to 219Rn (and perhaps 222Rn) which is potentially capable of beta minus, and 148Gd, 213At, 214At, 213Rn, 215Rn and many others that are potentially capable of beta plus? 129.104.241.214 (talk) 06:35, 24 October 2023 (UTC)
 * It is of interest mostly because 247Cm is so stable. I was quite surprised to learn that it was not the beta-stable isobar for 247. I don't object to it being removed if you think it's not suitable. :) Double sharp (talk) 14:23, 18 December 2023 (UTC)
 * OK, replaced the sentence with "Among non-primordial nuclides, there are some other cases of theoretically possible but never-observed beta decay, notably including 222Rn and 247Cm (the most stable isotopes of their elements considering all decay modes)." Double sharp (talk) 05:30, 19 December 2023 (UTC)
 * Just a digression: I found it unbelievable that the very unstable nuclide 146Sm has less energy than the stable 146Nd. 129.104.241.214 (talk) 09:16, 28 December 2023 (UTC)
 * Probably because 146Sm is two neutrons above the magic number. N = 84 has only one stable isotone, 142Ce (and it is double-beta-unstable anyway). IIRC Z = 58 is semimagic, filling 1g7/2 above the closed shell at Z = 50. So perhaps one could compare 142Ce with 210Pb, the least unstable N = 128 isotone. I think something similar will happen in the superheavy region as the beta-stability line passes N = 184.
 * The mismatch between the alpha-stable and beta-stable regions in the actinoids surprised me when I first thought about it, BTW. The most stable isotopes of Th, U, and Pu already suffer double beta decay! (Although we already see signs of it earlier, where only 204Hg is alpha-stable and beta-stable past Z = 66, the Q-values are too small to see the decay in experiments for now.) Double sharp (talk) 13:45, 28 December 2023 (UTC)
 * Thanks! The cases for 222Rn and 247Cm are indeed astonishing. I would think that 148Gd is equally surprising to have no decay mode of electron capture observed while being so proton-rich :) 129.104.241.214 (talk) 23:50, 27 December 2023 (UTC)
 * Agreed on 148Gd. With it gone, I think only 150Gd and 154Dy are non-primordial among beta-stable nuclides up to 209, excluding 5 and 8 for obvious reasons. (By the way I find it a bit odd to count 5, mostly because there is no bound nuclide with mass 5 at all. For mass 8 we have the peculiar irony that 8He, 8Li, and 8B are all bound, but the actually beta-stable 8Be is not.) Double sharp (talk) 13:45, 28 December 2023 (UTC)
 * I'm not sure that do 148Gd need to be mentioned at the chart. NUBASE2020 mentions its possible double beta decay. Nucleus hydro elemon (talk) 14:48, 28 December 2023 (UTC)
 * I added a note about 148Gd. It might well end up being a case like 48Ca or 96Zr: a beta decay that is energetically possible, but is so hindered that double beta decay happens first. Except that its alpha half-life is short, so good luck seeing either process. :( Double sharp (talk) 16:20, 28 December 2023 (UTC)
 * 146Sm is also non-primordial and beta stable. 129.104.241.214 (talk) 19:44, 28 December 2023 (UTC)
 * Eh, its half-life is long enough that tiny traces should persist from the Earth's formation. You are right though that it's not primordial in any useful sense :)
 * BTW, it's interesting that these form an alpha chain: 154Dy → 150Gd → 146Sm → 142Nd (stable at N = 82). Double sharp (talk) 02:32, 29 December 2023 (UTC)
 * P.S. the old Russian source I was mentioning above agrees with me about mass 5: it simply does not list anything at all. Double sharp (talk) 17:16, 29 December 2023 (UTC)
 * 148Gd is interesting mostly because its similar situation with 222Rn and 247Cm: it has reasonable alpha-decay half-life to study the single beta decay among non-primordial nuclides. I can't recall a fourth non-primordial nuclide with relatively long alpha half-life that is not beta-stable but with no beta decay observed.
 * Also, if 148Gd were beta-stable, it would be the 9th (!) beta-stable isotopes of Gd. It is actually quite close, with a theoretical EC decay energy of 26.668 keV. Actually such a process is infeasible due to the high spin change (0+ to 5-), see here. 129.104.241.214 (talk) 09:46, 8 January 2024 (UTC)

P.S. While we're talking about weirdness in the nuclide charts: the situation of Ar and Ce is pretty unusual, as the only beta-stable nuclides are even-even. This is the only time that happens in the first 100 elements. Double sharp (talk) 17:08, 29 December 2023 (UTC)


 * These two elements are directly affected by the magic numbers 20 and 82 as neutron numbers. 129.104.241.214 (talk) 15:47, 29 January 2024 (UTC)

Shape of beta-stable isotop(n)es for even Z and N
I am posting the two tables in the hope that some new patterns would be discovered in the future.

(⬛️=beta-stable, ◻️=not beta-stable) 2 ~ 6 beta-stable isotopes: one with odd mass (except that He, Ti, Hf, Po have two, and Ar, Ce have none);

7 ~ 9 beta-stable isotopes: two with odd mass (except that Cd and Te only have one, but they each have an isotope with odd mass that is nearly beta-stable (113Cd and 123Te));

10 beta-stable isotopes: three with odd mass.

Comparison of the three even-even nearly-beta-stable nuclides
I do not list 222Rn as being almost beta-stable, as its predicted 6.7×104 − 2.4×108 years β− half-life is far too short compared with a double beta decay; this is because the spin change 0+ → 2− (ΔJΔπ = 2−, 1 forbidden unique) of 222Rn → 222Fr is not high. The estimated β− half-life of 222Rn is similar to the EC half-life of 202Tl and the β− half-life of 250Cm. 129.104.241.214 (talk) 04:42, 31 January 2024 (UTC)

"Beta decay toward minimum mass" for 260Md
We only know that its EC branching ratio is <5% and β- is <3.5%. 129.104.241.214 (talk) 23:03, 13 February 2024 (UTC)

The Zagrebaev et al. prediction does not indicate which of 294Cn and 294Fl has lower energy
Odd Z nuclides sandwiched by two beta-stable isotopes, its isobar with one less proton having the lowest energy: 36Cl, 40K, 64Cu, 108Ag, 152Eu and 242Am.

Odd Z nuclides sandwiched by two beta-stable isotopes, its isobar with one more proton having the lowest energy: 70Ga, 80Br, 122Sb, 192Ir and 204Tl. If 261Md is beta-stable then 260Md is also in this list.

Odd N nuclides sandwiched by two beta-stable isotones, its isobar with one less neutron having the lowest energy: 98Tc and 146Pm.

Odd N nuclides sandwiched by two beta-stable isotones, its isobar with one more neutron having the lowest energy: none known. (Given the Zagrebaev et al. prediction, it's a question that which of 294Cn and 294Fl has lower energy.) 129.104.241.214 (talk) 01:18, 23 February 2024 (UTC)

Atomic/neutron numbers with an exceptional number of absolutely beta-stable isotop(n)es
An atomic number usually has at most 5 isotopes that have the lowest energies among their isobars;

Z = 50 has 7: 114Sn, 115Sn, 116Sn, 117Sn, 118Sn, 119Sn, 120Sn;

Z = 62 has 6: 146Sm (non primordial), 147Sm, 148Sm, 149Sm, 150Sm, 152Sm.

A neutron number usually has at most 3 isotones that have the lowest energies among their isobars;

N = 20 has 4: 36S, 37Cl, 38Ar, 39K;

N = 82 has 5: 138Ba, 139La, 140Ce, 141Pr, 142Nd. 129.104.241.218 (talk) 02:21, 18 March 2024 (UTC)