Which of the following isotopes is used for the treatment of cancer?

$A$ nuclear reactor provides power of $300 \, MW$. If $170 \, MeV$ of energy is released per fission of a $U^{235}$ nucleus, then the number of uranium atoms undergoing fission per hour is:

$A$ hydrogen bomb is based on which of the following phenomena?

Given that the mass of ${ }_{3}^{7} Li = 7.0160 \, u$,the mass of ${ }_{2}^{4} He = 4.0026 \, u$,and the mass of ${ }_{1}^{1} H = 1.0079 \, u$. When $20 \, g$ of ${ }_{3}^{7} Li$ is converted into ${ }_{2}^{4} He$ by proton capture,the energy liberated (in $kWh$) is: [Take $1 \, u = 931.5 \, MeV/c^2$ and $1 \, kWh = 3.6 \times 10^6 \, J$]

Which of the following statement$(s)$ is/are correct?
$(1)$ The rest mass of a stable nucleus is less than the sum of the rest masses of its constituent nucleons.
$(2)$ The rest mass of a stable nucleus is greater than the sum of the rest masses of its constituent nucleons.
$(3)$ Nuclear fusion involves the fusion of two light nuclei to form a heavier nucleus.
$(4)$ Nuclear fission involves the release of energy by the splitting of a heavy nucleus.

$A$ nucleus with mass number $220$ initially at rest emits an alpha particle. If the $Q$ value of the reaction is $5.5 \ MeV$,calculate the kinetic energy of the alpha particle. (in $MeV$)