Radioactivity is due to

If the mass defect of a nuclide is $3.32 \times 10^{-26} \ g$, its binding energy in $MeV$ is:

In a nuclide, one $a.m.u.$ of mass is dissipated into energy to bind its nucleons. The energy equivalent of this mass is

In the successive emission of $\alpha$- and $\beta$-particles,the number of $\alpha$- and $\beta$-particles that should be emitted for the conversion of ${}^{238}_{92}U$ to ${}^{206}_{82}Pb$ are:

If the mass defect of ${ }_{5}B^{11}$ is $0.081 \ u$,its average binding energy (in $MeV$) is