Rutherford designed an experiment to determine the structure of an atom. Answer the following in relation to this experiment:
$(a)$ Name the element he selected for this purpose.
$(b)$ Which subatomic particle was used by him?
$(c)$ What was the drawback of Rutherford's model of the atom?

(N/A) Rutherford selected gold for his experiment because it is highly malleable and can be beaten into a very thin foil.
$(b)$ He used $\alpha$-particles,which are doubly charged helium ions $(He^{2+})$.
$(c)$ The major drawback of Rutherford's model was that it could not explain the stability of the atom. According to classical electromagnetic theory,an accelerating charged particle should emit energy; thus,electrons revolving around the nucleus should lose energy and eventually fall into the nucleus,making the atom unstable.