(a(i))[2]
An unstable nucleus $^{A}_{Z}X$ undergoes decay by releasing a $\beta^{-}$ particle. Determine the changes, if any, in $A$ and $Z$ after $X$ decays.
(a(ii))[1]
Besides the $\beta^{-}$ particle, another lepton is produced in the decay. State the name of this second emitted lepton.
(b(i))[2]
Particle $P$ consists of an up quark $(u)$ and a down antiquark $(\bar{d})$. Calculate the charge $q$ of particle $P$ in terms of $e$, where $e$ is the elementary charge. Show your working.
(b(ii))[2]
Particle $P$ is in two classes (groups) of particles. State the names of these two classes.