Which is the correct statement about a proton?

The nucleus and an atom can be assumed to be spherical. The radius of the nucleus of mass number $A$ is given by $R_n = 1.25 \times 10^{-13} \times A^{1/3} \, \text{cm}$. The atomic radius is $1 \, \mathring{A}$. If the mass number is $64$,the fraction of the atomic volume that is occupied by the nucleus is:

Positive charge in an atom is:

Which one of the following pairs is not correctly matched?

What is the ratio of the mass of an electron to the mass of a proton?

The discovery of ......... was made through Rutherford's scattering experiment.