$A$ beam of fast-moving alpha particles was directed towards a thin gold foil. The parts $A'$,$B'$,and $C'$ of the transmitted and reflected beams corresponding to the incident parts $A$,$B$,and $C$ of the beam are shown in the adjoining diagram. The number of alpha particles in:

State the limitations of the plum pudding model of the atom.

The size of an atom is of the order of:

We consider the Thomson model of the hydrogen atom in which the proton charge is distributed uniformly over a spherical volume of radius $R = 0.25 \,\mathring A$. Applying the Bohr quantization condition in this model,the ground state energy (in $eV$) of the electron will be close to:

What radioactive source did Geiger and Marsden use in the scattering experiment?

In an alpha particle scattering experiment,the distance of closest approach for the $\alpha$-particle is $4.5 \times 10^{-14} \ m$. If the target nucleus has an atomic number $Z = 80$,then the maximum velocity of the $\alpha$-particle is approximately $... \times 10^5 \ m/s$.
$\left(\frac{1}{4 \pi \epsilon_0} = 9 \times 10^9 \ SI \ unit, \text{mass of } \alpha \text{-particle } m = 6.72 \times 10^{-27} \ kg, e = 1.6 \times 10^{-19} \ C\right)$