What is the energy released in the process $3 \, _{2}^{4}\text{He} \to _{6}^{12}\text{C}$ (in $, \text{MeV}$)? (Mass of $_{2}^{4}\text{He} = 4.002604 \, \text{amu}$,mass of $_{6}^{12}\text{C} = 12 \, \text{amu}$)

Which of the following are suitable for the fusion process?

Match the $\text{LIST-I}$ with $\text{LIST-II}$:

$A. \text{ } _0^1 n + { }_{92}^{235} U \rightarrow { }_{54}^{140} Xe + { }_{38}^{94} Sr + 2_0^1 n$	$I. \text{ Chemical reaction}$
$B. \text{ } 2H_2 + O_2 \rightarrow 2H_2O$	$II. \text{ Fusion with } +ve \ Q \text{ value}$
$C. \text{ } _1^2 H + _1^2 H \rightarrow _2^3 He + _0^1 n$	$III. \text{ Fission}$
$D. \text{ } _1^1 H + _1^3 H \rightarrow _1^2 H + _1^2 H$	$IV. \text{ Fusion with } -ve \ Q \text{ value}$

Choose the correct answer from the options given below:

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

$A$ nuclear fission process is given by $A^{240} \rightarrow B^{100} + C^{140} + Q$ (energy). If the binding energy per nucleon for nuclei $A, B,$ and $C$ are $7.6 \, MeV, 8.1 \, MeV,$ and $8.1 \, MeV$ respectively,then the energy $Q$ released is approximately $...... \, MeV$.

Slowing down of neutrons: In a nuclear reactor,a neutron of high speed (typically $10^{7} \; m s^{-1}$) must be slowed to $10^{3} \; m s^{-1}$ so that it can have a high probability of interacting with isotope $^{235}_{92}U$ and causing it to fission. Show that a neutron can lose most of its kinetic energy in an elastic collision with a light nucleus like deuterium or carbon,which has a mass of only a few times the neutron mass. The material making up the light nuclei,usually heavy water $(D_{2}O)$ or graphite,is called a moderator.