The nuclear radius of a hydrogen atom is approximately . . . . . . . (in $fm$)

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.

Explain the types of atoms by illustrating with examples.

If the surface areas of two nuclei are in the ratio $9 : 49$, then the ratio of their mass numbers is

Let the binding energy per nucleon of a nucleus be denoted by $E_{bn}$ and the radius of the nucleus be denoted by $r$. If the mass numbers of nuclei $A$ and $B$ are $64$ and $125$ respectively, then:

In the nuclear reaction: $X(n, \alpha) {_3Li^7}$,the term $X$ will be