1. The problem statement, all variables and given/known data The atomic mass of 55 25Mn = 54.938047u and that of 55 26Fe=54.938296u. Explain which of the three possible β-decay processes involving these two nuclides are forbidden, and which can occur. For decays which can occur, describe the energy spectrum of the products. 2. Relevant equations In all the cases where β+ decay is allowed energetically (and the proton is a part of a nucleus with electron shells), it is accompanied by the electron capture process) . However, in proton-rich nuclei where the energy difference between initial and final states is less than 2mec2, then β+ decay is not energetically possible, and electron capture is the sole decay mode. 3. The attempt at a solution β+ decay can only happen inside nuclei when the value of the binding energy of the mother nucleus is less than that of the daughter nucleus. B.E of Fe = 481.050477 Mev B.E of Mn = 482.033 Mev So β+ decay seems possible. Also there is no reason to exclude b- and electron capture processes . Im also confused about the energy spectrum of created nuclei . How would be possible to know their K.E ??