The three stable isotopes of neon: $_{10}^{20}Ne$,$_{10}^{21}Ne$,and $_{10}^{22}Ne$ have respective abundances of $90.51\%$,$0.27\%$,and $9.22\%$. The atomic masses of the three isotopes are $19.99\;u$,$20.99\;u$,and $21.99\;u$ respectively. Obtain the average atomic mass of neon. (in $;u$)

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

The radius of a nucleus of a mass number $A$ is directly proportional to

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

Four statements are given ($A$ is mass number) :
$A$. The volume of a nucleus is proportional to $A^{1/3}$.
$B$. The volume of a nucleus is proportional to $A$.
$C$. The difference in mass of an atom and its nucleus is called the mass defect.
$D$. The difference in mass of a nucleus and its constituents is called the mass defect.
Choose the correct answer from the options given below :

Which of the following pairs is called isotones?