The mass of a neutron is approximately the same as that of:

$A$ free neutron decays into a proton,but a free proton does not decay into a neutron. This is because

An atom ${}_3^8 X$ is bombarded by a shower of fundamental particles. In $10 \ s$,this atom absorbs $10$ electrons,$10$ protons,and $9$ neutrons. The percentage growth in the surface area of the nucleus is recorded as: (in $\%$)

The atomic number of a nucleus is $Z$ and the atomic mass number is $M$. The number of neutrons is

The radius of ${ }_{52} Te^{125}$ nucleus is $6 \text{ fermi}$. The radius of ${ }_{13} Al^{27}$ nucleus in meters is

The ratio of the specific charge of an $\alpha$-particle to that of a proton is