Emanation symbol edit

One sometimes finds the symbol Em when this was the element's name; I wonder if it goes back to Rutherford? Double sharp (talk) 12:22, 3 February 2021 (UTC)Reply

Comparison of three even-even nuclides with medium beta decay half-lives edit

Decay process Qβ (keV) Spin change Half-life (a)
202Pb → 202Tl 49.7 0+ → 2JΔπ = 2, 1 forbidden unique) 5.25×104
222Rn → 222Fr 24 0+ → 2JΔπ = 2, 1 forbidden unique) 6.7×104−2.4×108 (predicted)
250Cm → 250Bk 37.7 0+ → 2JΔπ = 2, 1 forbidden unique) 1.04×105

I believe that it is still possible to observe β decays of 222Rn and 248Bk (EC decay to the 6+ state of 248Cm with Q value 391.3 keV or β decay to the 6+ state of 248Cf with Q value 557.6 keV), as opposed to that of 216Ra. 129.104.241.162 (talk) 03:26, 6 March 2024 (UTC)Reply