The radius of a Germanium $(Ge)$ nucleus is twice the radius of a $^9_4Be$ nucleus. The number of nucleons in $Ge$ is ......

If the radii of ${}_{13}^{27}Al$ and ${}_{30}^{64}Zn$ nuclei are $R_{1}$ and $R_{2}$ respectively,then $\frac{R_{1}}{R_{2}} = $

$A$ nucleus splits into two nuclear fragments. If the ratio of their velocities is $2:1$,then the ratio of their nuclear radii is:

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

Which of the following pairs of nuclei represents isotones?

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.