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 binding energy per nucleon of deuteron $({ }_{1} H^{2})$ and the helium atom $({ }_{2} He^{4})$ are $1.1 \ MeV$ and $7 \ MeV$ respectively. If two deuteron nuclei fuse to form a single helium nucleus,then the energy released is: (in $MeV$)

According to classical physics,$10^{-15} \ m$ is the distance of closest approach $(d_c)$ for fusion to occur between two protons. $A$ more accurate quantum approach states that $d_c = \frac{\lambda_p}{\sqrt{2}}$,where $\lambda_p$ is the de Broglie wavelength of a proton when they were far apart. Using this quantum approach,find the equation for the temperature $(T_c)$ at the center of a star. [Given: $M_p$ is the mass of the proton,$k$ is the Boltzmann constant,$e$ is the elementary charge]

In the fusion reaction,${ }_1 H^2+{ }_1 H^2 \rightarrow{ }_2 He^4+Q$,where $Q$ is the energy released. If $c$ is the speed of light and $m$ is the mass of each deuterium nucleus,then the mass of the helium nucleus formed is:

$_1H^1 + _1H^1 + _1H^2 \to X + _1e^0 + \text{Energy}$. The emitted particle $X$ is ........?

$A$ $\pi^0$ meson at rest decays into $2$ $\gamma$ rays: $\pi^0 \to \gamma + \gamma$. Which of the following must happen?