In Rutherford's $\alpha$-particle scattering experiment,which of the following was discovered?

Find the number of atoms in $39.4 \ g$ of gold. The molar mass of gold is $197 \ g \ mol^{-1}$.

An alpha nucleus of energy $\frac{1}{2}mv^2$ bombards a heavy nuclear target of charge $Ze$. Then the distance of closest approach for the alpha nucleus will be proportional to

An $\alpha$-particle of energy $4 \text{ MeV}$ is scattered through $180^\circ$ by a fixed uranium nucleus. The distance of the closest approach is of the order of

Statement $(A)$: As one considers orbits with higher values of $n$ in a hydrogen atom,the electric potential energy of the atom increases.
Statement $(B)$: In Thomson's model,an atom is a spherical cloud of positive charges with electrons embedded in it.
Statement $(C)$: The orbital picture in Bohr's model of the hydrogen atom was consistent with the uncertainty principle.

Who discovered the spin quantum number?