${\mathrm{Zn}}^{69}$ has two isomeric states differing by 0.47 Mev in energy. The upper state decays into the lower with a half-life of 13.8 hours, emitting a gamma-ray which has an internal conversion coefficient less than 0.1. The lower isomeric state decays to ${\mathrm{Ga}}^{69}$ with a half-life of 57 minutes. The most probable value for the spin difference between the isomeric states is five.

• Received 6 October 1939

DOI:https://doi.org/10.1103/PhysRev.56.1095