(a)[1]
State the particle class that contains $\beta^{+}$.
(b)[1]
For nucleus $X$, state how many protons and how many neutrons it has.
(c)[3]
The carbon-13 nucleus has a mass of $2.2 \times 10^{-26}\,\text{kg}$. Its kinetic energy because of the decay is $0.80\,\text{MeV$.} Calculate the speed of this nucleus.
(d)[1]
Explain why the combined kinetic energies of the carbon-13 nucleus and the $\beta^{+}$ particle cannot be the same as the total energy released by the decay process.