Physics (AS & A Level) · May / June 2021 · Paper 12 · Question 39

A nucleus of magnesium decays into a nucleus X by emitting a β+ particle. The decay is represented by the equation shown. \[^{23}_{12}\text{Mg} \rightarrow {}^{P}_{Q}\text{X} + {}^{0}_{1}\beta^{+}\] What are the values of P and Q?

1. AP = 22, Q = 11
2. BP = 22, Q = 13
3. CP = 23, Q = 11
4. DP = 23, Q = 13

As printed in the paper