An atom ${}_3^8 X$ is bombarded by a shower of fundamental particles. In $10 \ s$, this atom absorbs $10$ electrons, $10$ protons, and $9$ neutrons. The percentage growth in the surface area of the nucleus is recorded as: (in $\%$)

Which of the following is a fundamental force in nature?

$A$ nucleus at rest disintegrates into two smaller nuclei with their masses in the ratio of $2:1$. After disintegration,they will move:

The ratio of mass densities of nuclei of $^{40}Ca$ and $^{16}O$ is close to

$A$ radioactive nucleus of mass $M$ emits a photon of frequency $f$ and the nucleus recoils. The recoil energy will be

Given below are three schematic graphs of potential energy $V(r)$ versus distance $r$ for three atomic particles: electron $(e^{-})$,proton $(p^{+})$,and neutron $(n)$,in the presence of a nucleus at the origin $O$. The radius of the nucleus is $r_0$. The scale on the $V$-axis may not be the same for all figures. The correct pairing of each graph with the corresponding atomic particle is