(a)[2]
A consequence of the $\alpha$-particle scattering experiment is that a very small fraction of the $\alpha$-particles are deflected through angles greater than $90^\circ$. State what can be deduced about the atom's structure from this observation.
(b)
A hadron carries an overall charge of $+e$, where $e$ is the elementary charge. It contains three quarks, and one of them is a strange ($s$) quark.
(b(i))[1]
State the electric charge of the strange ($s$) quark, expressed in terms of $e$.
(b(ii))[2]
The two remaining quarks have the same charge. Use the charge information to work out a possible flavour for those two quarks. Show your working.