In a fission reaction ${}_{92}^{236}U \to {}^{117}X + {}^{117}Y + n + n$,the binding energy per nucleon of $X$ and $Y$ is $8.5\,MeV$,whereas that of ${}^{236}U$ is $7.6\,MeV$. The total energy liberated will be about:

Fusion reaction is initiated with the help of

If the binding energy per nucleon of deuteron $({ }_1 H^2)$ is $1.15 \text{ MeV}$ and an $\alpha$-particle has a binding energy of $7.1 \text{ MeV}$ per nucleon,then the energy released per nucleon in the given reaction is ${ }_1 H^2 + { }_1 H^2 \rightarrow { }_2 He^4 + Q$. (in $\text{ MeV}$)

In the proton-proton cycle in the Sun,the energy released when an electron and its antiparticle combine is $\qquad$ .

What is a moderator? Name the material used as a moderator in a nuclear reactor.

The number of neutrons released when ${}_{92}^{235}U$ undergoes fission by absorbing ${}_{0}^{1}n$ and products ${}_{56}^{144}Ba$ and ${}_{36}^{89}Kr$ are formed,is: