(a(i))[1]
Result 1: Most of the $\alpha$-particles travel directly through the metal foil, or are turned through small angles. State what can be deduced from result 1.
(a(ii))[2]
Result 2: Only a very small number of $\alpha$-particles are scattered through angles greater than $90^\circ$. State what can be deduced from result 2.
(b(i))[2]
A radioactive decay chain has four nuclei, $P$, $Q$, $R$ and $S$, as shown. $$^{218}_{84}P \rightarrow {}^{214}_{82}Q \rightarrow {}^{214}_{83}R \rightarrow S.$$ Nucleus $S$ is an isotope of nucleus $P$. Determine the proton number and the nucleon number of nucleus $S$.
(b(ii))[1]
The quark composition of a nucleon in $Q$ changes as $Q$ decays to form $R$. Describe how the quark composition of the nucleon changes.