1. a Deviations from Rutherford scattering are expected when the alpha particles reach large energies. Suggest an explanation for this observation.
2. b Some alpha particles are directed at a thin foil of gold ( Z=79 ) and some others at a thin foil of aluminium ( Z=13 ). Initially, all alpha particles have the same energy. This energy is gradually increased. Predict in which case deviations from Rutherford scattering will first be observed.