Talk:Mattauch isobar rule

Electron Capture
It might be mentioned that the rule is only valid if one includes electron-capture as a decay mode. It is hypothetically possible for the mass difference to be small enough that neither an electron in one, nor a positron in the other, can be created. That would enable two adjacent bare nuclei to be absolutely stable. That's the case for 7Li and 7Be. But once an electron is bound, to the nucleus, it appears that electron capture can occur if beta decay can't. — Preceding unsigned comment added by Johnm307 (talk • contribs) 17:57, 5 February 2021 (UTC)

247
247 also seems to be a violation, at least under the looser wording of this rule. 247Cm and 247Bk are of course both unstable, but neither has been observed to undergo beta decay. 247Cm should theoretically release energy with beta decay to 247Bk, but small decay energy and large spin difference inhibits it. Double sharp (talk) 05:13, 1 January 2022 (UTC)