What is the ratio of the radii of the nuclei $_{13}^{27}Al$ and $_{52}^{125}Te$?

Consider a nucleus ${ }_{30}^{60} X$. Its approximate density is (Take $1 \text{ amu} = 1.6 \times 10^{-27} \text{ kg}$,$R_0 = 1.2 \times 10^{-15} \text{ m}$)

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 $\text{ fermi}$)

The mass number of $He$ is $4$ and that for sulphur is $32$. The radius of the sulphur nucleus is larger than that of the helium nucleus by a factor of:

The charge density $P$ in a nucleus varies with distance $r$ from the centre of the nucleus according to the curve in the figure. Which of the following graphs correctly represents this variation?

Consider the following statements:
$I$. All isotopes of an element have the same number of neutrons.
$II$. Only one isotope of an element can be stable and non-radioactive.
$III$. All elements have isotopes.
$IV$. All isotopes of carbon can form chemical compounds with oxygen-$16$.
Choose the correct option regarding an isotope.