$A$ nucleus disintegrates into two smaller parts,which have their velocities in the ratio $3: 2$. The ratio of their nuclear sizes will be $\left(\frac{x}{3}\right)^{\frac{1}{3}}$. The value of '$x$' is:

Which of the following is true for a sample of isotopes containing $^{235}U$ and $^{238}U$?

Define isotopes,isobars,and isotones.

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

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: The nuclear density of nuclides ${ }_{5}^{10} B, { }_{3}^{6} Li, { }_{26}^{56} Fe, { }_{10}^{20} Ne$ and ${ }_{83}^{209} Bi$ can be arranged as $\rho_{ Bi }^{ N } > \rho_{ Fe }^{ N } > \rho_{ Ne }^{ N } > \rho_{ B }^{ N } > \rho_{ Li }^{ N }$.
Reason $R$: The radius $R$ of a nucleus is related to its mass number $A$ as $R = R_0 A^{1/3}$,where $R_0$ is a constant.
In the light of the above statements,choose the correct answer from the options given below:

$A$ neutrino is a particle which: