Compare and contrast and angle of deflection of `alpha`-rays in `alpha`-ray scattering experiment carried out by taking aluminium foil and gold foil. Justify.

Explanation

In the normal `alpha`-ray scattering experiment, a gold foil is used. In the place of the gold foil, if aluminium foil is used, the angle of deflection will be less. Charge and mass of aluminium nucleus is less than that of gold nucleus. So, the repulsive forces experienced by `alpha`-rays and the impact due to the collision with the aluminium nuclei are less. Hence, the angle of deflections will be less in `alpha`-ray scattering experiment using aluminium foil instead of gold foil.