The isotope ${ }_5^{12} \mathrm{~B}$ having a mass $12.014 \mathrm{u}$ undergoes $\beta$-decay to ${ }_6^{12} \mathrm{C} .{ }_6^{12 .}$ has an excited state of the nucleus $\left({ }_6^{12} \mathrm{C}^*\right)$ at $4.041 \mathrm{MeV}$ above its ground state. If ${ }_5^{12} \mathrm{~F}$ decays to ${ }_6^{12} \mathrm{C}^*$, the maximum kinetic energy of the $\beta$-particle in units of $\mathrm{MeV}$ is ( $1 \mathrm{u}=931.5 \mathrm{MeV} / c^2$, where $c$ is the speed of light in vacuum).

Before the neutrino hypothesis, the beta decay process was thought to be the transition, $n \to p + {e^ - }$ If this was true, show that if the neutron was at rest, the proton and electron would emerge with fixed energies and calculate them. Experimentally, the electron energy was found to have a large range. 

If a heavy nucleus has $N / Z$ ratio higher than that required for stability, then

$\alpha$ -particle consists of 

Which of the following is a correct statement

What is the respective number of $\alpha $ and $\beta $ particles emitted in the following radioactive decay

$_{90}{X^{200}}{ \to _{80}}{Y^{168}}$