A magnesium nucleus undergoes decay to form a nucleus X, with a $\beta^+$ particle being emitted. The decay is shown by the equation $^{23}_{12}\text{Mg} \rightarrow {}^{P}_{Q}\text{X} + {}^{0}_{+1}\beta^+$. What are the values of $P$ and $Q$?
Physics 9702 · AS & A Level · Atoms, nuclei and radiation