In a hypothetical fission reaction
${ }_{92} X^{236} \rightarrow{ }_{56} Y^{141}+{ }_{36} Z^{92}+3 R$
The identity of emitted particles $(R)$ is :

The minimum kinetic energy needed by an alpha particle to cause the nuclear reaction ${ }_{7}^{16} N +{ }_{2}^{4} He \rightarrow{ }_{1}^{1} H +{ }_{8}^{19} O$ in a laboratory frame is $n$ (in $MeV$). Assume that ${ }_{7}^{16} N$ is at rest in the laboratory frame. The masses of ${ }_{7}^{16} N, { }_{2}^{4} He, { }_{1}^{1} H$ and ${ }_{8}^{19} O$ can be taken to be $16.006 \ u, 4.003 \ u, 1.008 \ u$ and $19.003 \ u$,respectively,where $1 \ u = 930 \ MeV/c^2$. The value of $n$ is. . . . .

In the following nuclear reaction, $x$ is: ${ }_{13} Al^{27} + { }_2 He^4 \rightarrow { }_0 n^1 + X$

Control rods used in nuclear reactors are made of:

In a nuclear reactor,boron rods are used as ...... .

Assertion: Heavy water is a better moderator than normal water.
Reason: Heavy water absorbs neutrons more efficiently than normal water.