The density (in $kg m^{-3}$) of nuclear matter is of the order of

The volume of a nucleus is directly proportional to

${ }_{92}^{238} U$ and ${ }_{90}^{236} Th$ are $\qquad$ of each other.

In a periodic table,the average atomic mass of magnesium is given as $24.312 \; u$. This average value is based on their relative natural abundance on Earth. The three isotopes and their masses are $_{12}^{24} Mg \; (23.98504 \; u)$,$_{12}^{25} Mg \; (24.98584 \; u)$,and $_{12}^{26} Mg \; (25.98259 \; u)$. The natural abundance of $_{12}^{24} Mg$ is $78.99 \%$. Calculate the abundances of the other two isotopes.

$A$ heavy nucleus at rest breaks into two fragments which fly off with velocities in the ratio $8 : 1$. Find the ratio of the radii of the fragments.

The ratio of the density of oxygen nucleus $(_{8}^{16}O)$ and helium nucleus $(_{2}^{4}He)$ is (in $: 1$)