The ratio of the nuclear radii of elements with mass numbers $216$ and $125$ is

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

$A$ neutrino is a particle which:

The radius of germanium $(Ge)$ nuclide is measured to be twice the radius of ${ }_4^9 Be$. The number of nucleons in $Ge$ will be

Which of the following pairs is called isotones?

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 $;u$)