Who invented neutron ? 

From the relation $R=R_{0} A^{1 / 3},$ where $R_{0}$ is a constant and $A$ is the mass number of a nucleus, show that the nuclear matter density is nearly constant (i.e. independent of $A$).

The charge density in a nucleus varies with distance from the centre of the nucleus according to the curve in Fig.

The mass of a neutron is the same as that of