In the nuclear reaction $X(n, \alpha) _3^7Li$,what is $X$?

The radius of the nucleus of silver (atomic number $Z = 47$) is $3.4 \times 10^{-14} \ m$. Calculate the electric potential on the surface of the nucleus. (Given: $e = 1.6 \times 10^{-19} \ C$,$\frac{1}{4\pi\epsilon_0} = 9 \times 10^9 \ N \ m^2/C^2$)

$A$ nucleus at rest splits into two nuclear parts having the same density and radii in the ratio $1:2$. Their velocities are in the ratio $\qquad$ . (in $:1$)

The nuclear forces are

The radius of the nucleus of an atom whose mass number is $125$ is:

How is the radius of the nucleus estimated? Write its relation to the radius and atomic mass number.