If the radius of a nucleus with mass number $125$ is $1.5 \text{ fermi}$, then the radius of a nucleus with mass number $64$ is: (in $\text{ fermi}$)

In the $_{88}Ra^{226}$ nucleus,there are

$A$ nucleus with atomic mass number $A$ produces another nucleus by losing $2$ alpha particles. The volume of the new nucleus is $60$ times that of the alpha particle. The atomic mass number $A$ of the original nucleus is:

If the radius of the $^{27}_{13}Al$ nucleus is taken to be $R_{Al}$,then the radius of the $^{125}_{53}Te$ nucleus is nearly

$A$ neutrino is a particle,which is

The radius of the nucleus of ${ }_{13}^{27} Al$ is $\qquad$ . (Given: $R_{0}=1.2 \text{ fm}$)