$A$ nucleus is bombarded with a high-speed neutron so that the resulting nucleus is a radioactive one. This phenomenon is called:

Mention the disadvantages of the nuclear reactor.

For the nuclear fusion reaction ${ }_1^2 H +{ }_1^3 H \rightarrow{ }_2^4 He +{ }_0^1 n$,the temperature to which the gases must be heated is $3.7 \times 10^9 \, K$. The potential energy between two nuclei is closest to ........ $J$ (Boltzmann's constant $k = 1.38 \times 10^{-23} \, J/K$).

Which one of the following nuclear reactions is a source of energy in the sun?

The binding energies per nucleon for a deuteron $(_{1}H^{2})$ and an $\alpha$-particle $(_{2}He^{4})$ are $x_1$ and $x_2$ respectively. What will be the energy $Q$ released in the reaction $_{1}H^{2} + _{1}H^{2} \to _{2}He^{4} + Q$?

Two lithium nuclei in a lithium vapour at room temperature do not combine to form a carbon nucleus because