(a) Which metal did Rutherford select for his α-particle scattering experiment and why ?

(b) What do you think would be the observation of α-particle scattering experiment if carried out on

(i) heavy nucleus like platinum

(ii) light nuclei like lithium.

(a) Rutherford selected gold for his α-particle scattering experiment as he wanted as thin a layer as possible and gold is the most malleable metal.

(b) (i) Heavy nucleus like platinum will show the same observation with α-particles as shown by gold foil.

1. Most of the α-particle will pass straight.
2. Some α-particle will slightly deflect from their straight path.
3. Very few will be deflected by very large angles or completely bounce back.

(ii) If light nuclei like lithium is used then fast moving α-particles may even push the light nucleus aside and may not be deflected back.