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?

Decaying nuclide	You list as stable	You list as unstable
17 Chlorine-36	2% to Sulfur-36	98% to Argon-36
19 Potassium-40	11.2% to Argon-40	89% to Calcium-40
47 Silver-108	0% to Palladium-108	100% to Cadmium-108
61 Promethium-146	37% to Samarium-146	63% to Neodymium-146

See also: User:JWB/Isotopes_by_isobar

--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)

External links modified

Hello fellow Wikipedians,

I have just modified one external link on Beta-decay stable isobars. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

• Added archive https://web.archive.org/web/20131217155419/http://wsyachina.narod.ru/physics/all_matter/sist-1a.jpg to http://wsyachina.narod.ru/physics/all_matter/sist-1a.jpg

When you have finished reviewing my changes, please set the checked parameter below to true or failed to let others know (documentation at {{Sourcecheck}}).

This message was posted before February 2018. After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{source check}} (last update: 18 January 2022).

• If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
• If you found an error with any archives or the URLs themselves, you can fix them with this tool.

Cheers.—InternetArchiveBot (Report bug) 23:35, 31 October 2016 (UTC)

The Russian prediction (linked) for the continuation of the line of beta stability to the superheavy region

All beta-decay stable isobars with A ≤ 312 sorted by mass number

Odd A	Even A	Odd A	Even A	Odd A	Even A	Odd A	Even A
1H	2H	3He	4He	5He (n)	6Li	7Li	8Be (α)
9Be	10B	11B	12C	13C	14N	15N	16O
17O	18O	19F	20Ne	21Ne	22Ne	23Na	24Mg
25Mg	26Mg	27Al	28Si	29Si	30Si	31P	32S
33S	34S	35Cl	36S ← 36Ar	37Cl	38Ar	39K	40Ar ← 40Ca
41K	42Ca	43Ca	44Ca	45Sc	46Ca → 46Ti	47Ti	48Ti
49Ti	50Ti ← 50Cr	51V	52Cr	53Cr	54Cr ← 54Fe	55Mn	56Fe
57Fe	58Fe ← 58Ni	59Co	60Ni	61Ni	62Ni	63Cu	64Ni ← 64Zn
65Cu	66Zn	67Zn	68Zn	69Ga	70Zn → 70Ge	71Ga	72Ge
73Ge	74Ge ← 74Se	75As	76Ge → 76Se	77Se	78Se ← 78Kr	79Br	80Se → 80Kr
81Br	82Se → 82Kr	83Kr	84Kr ← 84Sr	85Rb	86Kr → 86Sr	87Sr	88Sr
89Y	90Zr	91Zr	92Zr ← 92Mo	93Nb	94Zr → 94Mo	95Mo	96Mo ← 96Ru
97Mo	98Mo → 98Ru	99Ru	100Mo → 100Ru	101Ru	102Ru ← 102Pd	103Rh	104Ru → 104Pd
105Pd	106Pd ← 106Cd	107Ag	108Pd ← 108Cd	109Ag	110Pd → 110Cd	111Cd	112Cd ← 112Sn
113In	114Cd → 114Sn	115Sn	116Cd → 116Sn	117Sn	118Sn	119Sn	120Sn ← 120Te
121Sb	122Sn → 122Te	123Sb	124Sn → 124Te ← 124Xe	125Te	126Te ← 126Xe	127I	128Te → 128Xe
129Xe	130Te → 130Xe ← 130Ba	131Xe	132Xe ← 132Ba	133Cs	134Xe → 134Ba	135Ba	136Xe → 136Ba ← 136Ce
137Ba	138Ba ← 138Ce	139La	140Ce	141Pr	142Ce → 142Nd	143Nd	144Nd (α) ← 144Sm
145Nd	146Nd → 146Sm (α)	147Sm (α)	148Nd → 148Sm (α)	149Sm	150Nd → 150Sm ← 150Gd (α)	151Eu (α)	152Sm ← 152Gd (α)
153Eu	154Sm → 154Gd ← 154Dy (α)	155Gd	156Gd ← 156Dy	157Gd	158Gd ← 158Dy	159Tb	160Gd → 160Dy
161Dy	162Dy ← 162Er	163Dy	164Dy ← 164Er	165Ho	166Er	167Er	168Er ← 168Yb
169Tm	170Er → 170Yb	171Yb	172Yb	173Yb	174Yb ← 174Hf	175Lu	176Yb → 176Hf
177Hf	178Hf	179Hf	180Hf ← 180W (α)	181Ta	182W	183W	184W ← 184Os (α)
185Re	186W → 186Os (α)	187Os	188Os	189Os	190Os ← 190Pt (α)	191Ir	192Os → 192Pt
193Ir	194Pt	195Pt	196Pt ← 196Hg	197Au	198Pt → 198Hg	199Hg	200Hg
201Hg	202Hg	203Tl	204Hg → 204Pb	205Tl	206Pb	207Pb	208Pb
209Bi (α)	210Po (α)	211Po (α)	212Po (α) ← 212Rn (α)	213Po (α)	214Po (α) ← 214Rn (α)	215At (α)	216Po (α) → 216Rn (α)
217Rn (α)	218Rn (α) ← 218Ra (α)	219Fr (α)	220Rn (α) → 220Ra (α)	221Ra (α)	222Ra (α)	223Ra (α)	224Ra (α) ← 224Th (α)
225Ac (α)	226Ra (α) → 226Th (α)	227Th (α)	228Th (α)	229Th (α)	230Th (α) ← 230U (α)	231Pa (α)	232Th (α) → 232U (α)
233U (α)	234U (α)	235U (α)	236U (α) ← 236Pu (α)	237Np (α)	238U (α) → 238Pu (α)	239Pu (α)	240Pu (α)
241Am (α)	242Pu (α) ← 242Cm (α)	243Am (α)	244Pu (α) → 244Cm (α)	245Cm (α)	246Cm (α)	247Bk (α)	248Cm (α) → 248Cf (α)
249Cf (α)	250Cf (α)	251Cf (α)	252Cf (α) ← 252Fm (α)	253Es (α)	254Cf (SF) → 254Fm (α)	255Fm (α)	256Cf (SF) → 256Fm (SF)
257Fm (α)	258Fm (SF) ← 258No (SF)	259Md (SF)	260Fm (SF) → 260No (SF)	261No (α, SF)	262No (SF)	263No (α, SF)	264No (SF) ← 264Rf (α, SF)
265Lr (α)	266No (SF) → 266Rf (SF)	267Rf (SF)	268Rf (α)	269Db (α)	270Rf (SF) ← 270Sg (α)	271Db (α, SF)	272Rf (SF) → 272Sg (α, SF)
273Sg (SF)	274Sg (SF)	275Sg (SF)	276Sg (SF) ← 276Hs (SF)	277Bh (SF)	278Hs (SF)	279Hs (SF)	280Hs (SF) ← 280Ds (SF)
281Hs (SF)	282Hs (SF) ← 282Ds (SF)	283Mt (SF)	284Ds (SF)	285Ds (SF)	286Ds (SF) ← 286Cn (SF)	287Ds (SF)	288Ds (SF) ← 288Cn (α, SF)
289Rg (SF)	290Cn (SF)	291Cn (SF)	292Cn (SF) ← 292Fl (α)	293Cn (α, SF)	294Cn (SF) → 294Fl (α)	295Fl (α)	296Fl (α)
297Fl (α)	298Fl (α) ← 298Lv (α)	299Mc (α)	300Fl (α, SF) → 300Lv (α)	301Lv (α)	302Lv (α)	303Lv (α, SF)	304Lv (SF) ← 304Og (α)
305Ts (SF)	306Lv (SF) → 306Og (SF)	307Og (SF)	308Og (SF)	309Og (SF)	310Og (SF) ← 310120 (SF) ?	311119 (SF) ?	312Og (SF) → 312120 (SF) ?

I would prefer something more recent, though. (Fairly obviously, all these nuclei must undergo α decay or spontaneous fission. Decay modes are from [1], 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: doi:10.1142/S0218301312500139. 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 ComplexRational for pasting it from your sandbox. :)

257Fm (α)	258Cf (SF) → 258Fm (SF) ← 258No (SF)	259Md (SF)	260Fm (SF) → 260No (SF)	261Md (α)	262Fm (SF) → 262No (SF)	263No (α)	264No (SF) ← 264Rf (SF)
265No (SF)	266No (SF) ← 266Rf (SF)	267Lr (SF)	268No (SF) → 268Rf (SF)	269Rf (SF)	270Rf (SF) ← 270Sg (SF)	271Rf (SF)	272Rf (SF) ← 272Sg (SF)
273Db (SF)	274Rf (SF) → 274Sg (SF) ← 274Hs (SF)	275Sg (SF)	276Rf (SF) → 276Sg (SF) ← 276Hs (SF)	277Sg (SF)	278Rf (SF) → 278Sg (SF) ← 278Hs (SF)	279Bh (SF)	280Sg (SF) → 280Hs (SF)
281Hs (SF)	282Sg (SF) → 282Hs (SF) ← 282Ds (SF)	283Hs (SF)	284Hs (SF) ← 284Ds (SF)	285Mt (α)	286Hs (SF) → 286Ds (SF)	287Ds (α)	288Hs (SF) → 288Ds (SF) ← 288Cn (α)
289Ds (α)	290Ds (α) ← 290Cn (α)	291Rg (α)	292Ds (α) → 292Cn (α) ← 292Fl (α)	293Cn (α)	294Ds (α) → 294Cn (α) ← 294Fl (α)	295Nh (α)	296Cn (α) → 296Fl (α)
297Nh (α)	298Fl (α)	299Fl (α)	300Fl (α) ← 300Lv (α)	301Mc (α)	302Fl (α) → 302Lv (α) ← 302Og (α)	303Lv (α)	304Fl (SF) → 304Lv (α) ← 304Og (α)
305Lv (α)	306Fl (SF) → 306Lv (SF) ← 306Og (α)	307Ts (α)	308Fl (SF) → 308Lv (SF) ← 308Og (SF)	309Ts (SF)	310Lv (SF) → 310Og (SF)	311Og (SF)	312Lv (SF) → 312Og (SF)
313Og (SF)	314Lv (SF) → 314Og (SF) ← 314120 (SF)	315Og (SF)	316Og (SF) ← 316120 (SF)	317119 (SF)	318Og (SF) → 318120 (SF)	319120 (SF)	320Og (SF) → 320120 (SF) ← 320122 (SF)

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: [2] [3] [4]

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)

@ComplexRational: 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)

@Double sharp: 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)

 Done as proposed for 109-111 (though it appears problematic in recent changes, why is that?) ComplexRational (talk) 23:43, 3 December 2018 (UTC)

@ComplexRational: 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)

@ComplexRational: 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)

@Double sharp: 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)

@ComplexRational: 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)

@Double sharp: 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)

@ComplexRational: 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)

@Double sharp: 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 1g_7/2 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)

Isotopes with even Z ≤ 96 (status of ²⁵⁸Cf not known for Z = 98)

Shape	Z
⬛️⬛️	4, 6
⬛️⬛️⬛️	2, 8, 10, 12, 14
⬛️◻️⬛️◻️⬛️	18
⬛️⬛️⬛️◻️⬛️	16, 40
⬛️◻️⬛️⬛️⬛️	24, 26, 38, 82
⬛️⬛️⬛️⬛️⬛️	22
⬛️◻️⬛️◻️⬛️◻️⬛️	58
⬛️◻️⬛️⬛️⬛️◻️⬛️	20, 28, 30, 34, 74, 96
⬛️◻️⬛️⬛️⬛️⬛️⬛️	72
⬛️⬛️⬛️⬛️⬛️◻️⬛️	84
⬛️◻️⬛️⬛️⬛️◻️⬛️◻️⬛️	34, 46, 94
⬛️◻️⬛️◻️⬛️⬛️⬛️◻️⬛️	36, 68, 78, 86
⬛️◻️⬛️⬛️⬛️⬛️⬛️◻️⬛️	42, 44, 70, 76, 80, 88, 90, 92
⬛️⬛️⬛️⬛️⬛️◻️⬛️◻️⬛️	56, 60
⬛️◻️⬛️◻️⬛️⬛️⬛️◻️⬛️◻️⬛️	48, 52
⬛️◻️⬛️⬛️⬛️⬛️⬛️◻️⬛️◻️⬛️	62
⬛️◻️⬛️◻️⬛️⬛️⬛️⬛️⬛️◻️⬛️	64
⬛️◻️⬛️◻️⬛️◻️⬛️⬛️⬛️⬛️⬛️	66
⬛️◻️⬛️◻️⬛️⬛️⬛️⬛️⬛️◻️⬛️◻️⬛️	54
⬛️◻️⬛️⬛️⬛️⬛️⬛️⬛️⬛️◻️⬛️◻️⬛️	50

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.

Isotones with even N ≤ 158 (status of ²⁵⁸Cf, ²⁶¹Md and ²⁶⁴Rf not known for N = 160)

Shape	N
⬛️	0, 2
⬛️⬛️	4, 6, 8
⬛️◻️⬛️	66, 120, 128
⬛️⬛️⬛️	10, 12, 14, 16, 18, 22, 24, 32, 34, 36, 38, 62, 100, 104, 110, 114, 118, 122, 124, 136, 140, 144, 148, 154
⬛️◻️⬛️◻️⬛️	26, 54, 56, 68, 76, 80, 84, 86, 92, 96, 102, 106, 112, 116, 134, 138, 142, 152, 156
⬛️⬛️⬛️◻️⬛️	28, 30, 40, 42, 46, 52, 70, 72, 94, 98, 108, 126, 130
⬛️◻️⬛️⬛️⬛️	44, 48, 60, 64, 132, 146, 150, 156
⬛️⬛️⬛️⬛️⬛️	20
⬛️◻️⬛️⬛️⬛️◻️⬛️	50, 58, 74, 78, 88, 90
⬛️◻️⬛️⬛️⬛️⬛️⬛️◻️⬛️	82

129.104.241.214 (talk) 21:41, 7 January 2024 (UTC)

Comparison of the three even-even nearly-beta-stable nuclides

Decay process	Z	N	Qβ (keV)	Spin change
48Ca → 48Sc	20	28	281.972	0+ → 6+ (ΔJΔπ = 6+, 6 forbidden non-unique)
96Zr → 96Nb	40	56	160.905	0+ → 6+ (ΔJΔπ = 6+, 6 forbidden non-unique)
148Gd → 148Eu	64	84	26.67	0+ → 5− (ΔJΔπ = 5−, 5 forbidden non-unique)

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⁻ (ΔJ^Δπ = 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)