The phenomenon of radioactivity arises from the

If two light nuclei are fused together in a nuclear fusion reaction,what happens to the average binding energy per nucleon?

$_{90}Th^{228}$ emits four alpha and one beta particles. The number of neutrons in the daughter element is:

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

India conducted an underground nuclear test at

Let $m_p$ be the mass of a proton,$m_n$ that of a neutron,$M_1$ that of a $_{10}^{20}Ne$ nucleus,and $M_2$ that of a $_{20}^{40}Ca$ nucleus. Then: