Fast neutrons can easily be slowed down by

When $_3^7Li$ nuclei are bombarded by protons, and the resultant nuclei are $_4^8Be$, the emitted particles will be

If the energy released per fission of a ${ }_{92}^{235} U$ nucleus is $200 \text{ MeV}$, the energy released in the fission of $0.1 \text{ kg}$ of ${ }_{92}^{235} U$ in kilowatt-hour is:

What is a nuclear chain reaction? Explain the difficulties and their removal for its successful operation.

The binding energy of deuteron $_1^2H$ is $1.112 \, MeV$ per nucleon and an $\alpha$-particle $_2^4He$ has a binding energy of $7.047 \, MeV$ per nucleon. Then in the fusion reaction $_1^2H + _1^2H \to _2^4He + Q$,the energy $Q$ released is ........ $MeV$.

$A$ nuclear reactor with $40\%$ efficiency produces $10^{14}$ fissions per second. Each fission releases $250 \text{ MeV}$ of energy. The power output of the reactor is ......... $W$.