A368859 Number of beta-stable isotopes of the n-th element.

2, 3, 2, 2, 2, 2, 2, 3, 1, 3, 1, 3, 1, 3, 1, 4, 2, 3, 2, 5, 1, 5, 1, 4, 1, 4, 1, 5, 2, 5, 2, 5, 1, 6, 2, 6, 1, 4, 1, 4, 1, 7, 0, 7, 1, 6, 2, 7, 1, 10, 2, 7, 1, 9, 1, 7, 1, 4, 1, 7, 0, 8, 2, 8, 1, 8, 1, 6, 1, 7, 1, 6, 1, 5, 1, 7, 2, 6, 1, 7, 2, 4, 1, 6, 1, 6, 1, 7, 1, 7, 1, 7, 1, 6, 2, 5, 1

Offset

1,1

Comments

A beta-stable nuclide is a nuclide whose beta decay (beta-minus and beta-plus decay) is energetically disallowed; that is to say, a nuclide that has lower energy than its isobars with one more or one less proton. Note that double beta decay is allowed. A nuclide whose beta decay is energetially allowed, even if not observed (in the case of 48Ca, 96Zr, 123Te, 148Gd, 180mTa, 222Rn and 247Cm), is not classified as being beta-stable.

We know 7 beta-stable isotopes of californium (248-252, 254, 256) and fermium (252, 254, 256-260) respectively, but the unobserved nuclides 258Cf and 262Fm could be beta-stable as well.

Different from A179301: for Z <= 83, 5He, 8Be, 146Sm, 150Gd and 154Dy are beta-stable but not primordial. 40K, 48Ca, 50V, 96Zr, 113Cd, 115In, 123Te, 138La, 176Lu, 187Re and 180mTa are primordial but not beta-stable.

Page 12 of the Zagrebaev et al. link predicts that a(113) = 0.

Prediction of a(98)-a(118) from a Russian source: 7, 1, 7, 1, 7, 1, 7, (1, 6 or 2, 5), 1, 4, 1, 7, 1, 7, 1, 7, 1, 7, 1, 7.

Prediction of a(98)-a(125) from pages 14-15 of the Hiroyuki Koura link: 8, 1, 8, 2, 8, 1, 10, 1, 9, 1, 10, 1, 9, 1, 6, 2, 10, 1, 10, 2, 13, 1, 9, 1, 9, 1, 9, 1.

Links

Table of n, a(n) for n=1..97.

Hiroyuki Koura, Decay Modes and a limit of existence of nuclei, 4th International Conference on the Chemistry and Physics of the Transactinide Elements. (See here for an excerpted table.)

Web Archive, The Russian prediction for the continuation of the line of beta stability to the superheavy region.

Wikipedia, Beta-decay stable isobars.

Valeriy Zagrebaev et al., Future of superheavy element research: Which nuclei could be synthesized within the next few years?, Journal of Physics: Conference Series, 420 (March 2013).

Example

a(2) = 3 because helium-3, -4 and -5 are beta-stable, even if helium-5 has an extremely short half-life.
a(4) = 2 because beryllium-8 and -9 are beta-stable, even if beryllium-8 has an extremely short half-life.
a(62) = 8 because the beta-stable isotopes of samarium are of mass numbers 144, 146-150, 152 and 154, with 146Sm being not primordial.
a(64) = 8 because the beta-stable isotopes of gadolinium are of mass numbers 150, 152, 154-158 and 160, with 150Gd being not primordial.
a(66) = 8 because the beta-stable isotopes of samarium are of mass numbers 154, 156, 158, 160-164, with 154Dy being not primordial.
a(84) = 6 because the beta-stable isotopes of polonium are of mass numbers 210-214 and 216.

Crossrefs

Cf. A368860 (beta-stable isotones), A367461 (isodiaphers), A179301.

Cf. A368887.

Sequence in context: A297930 A031217 A064131 * A338238 A355077 A111497

Adjacent sequences: A368856 A368857 A368858 * A368860 A368861 A368862

Keyword

nonn,fini,hard

Author

Jianing Song, Jan 08 2024

Status

approved