(a)[3]
Distinguish clearly between an $\alpha$-particle and a $\beta^+$-particle.
(b)[2]
State the equation that represents the decay of a particle in a nucleus that produces $\beta^+$ emission. Every particle in the equation should be shown using the notation normally used for nuclides.
(c(i))[2]
State the quark composition of (1) a proton, (2) a neutron.
(c(ii))[1]
Use the quark model to explain the proton's charge.