Chapter 30 - Nuclear Reactions and Elementary Particles - Learning Path Questions and Exercises - Exercises - Page 1031: 23

In a $beta^{+}$ decay, $P^{A}_{Z}=D^{A}_{Z-1}+e^{0}_{+1}$ so, $Q=(m_{p}-m_{D}-m_{e})c^{2}=[{(m_{p}+Zm_{e})-[m_{D}+(Z-1)m_{e}]-2m_{e}}]c^{2}=(M_{p}-M_{D}-2m_{e})c^{2}$ Hence, proved.

In a $beta^{+}$ decay, $P^{A}_{Z}=D^{A}_{Z-1}+e^{0}_{+1}$ so, $Q=(m_{p}-m_{D}-m_{e})c^{2}=[{(m_{p}+Zm_{e})-[m_{D}+(Z-1)m_{e}]-2m_{e}}]c^{2}=(M_{p}-M_{D}-2m_{e})c^{2}$ Hence, proved.