Pick out the correct statements from the following:
$I$. Electron emission during $\beta$-decay is always accompanied by neutrino.
$II$. Nuclear force is charge independent.
$III$. Fusion is the chief source of stellar energy.

$A$ 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 $...... \, MeV$.

The average energy released per fission for the nucleus of $_{92}^{235} U$ is $190 \text{ MeV}$. When all the atoms of $47 \text{ g}$ pure $_{92}^{235} U$ undergo fission process, the energy released is $\alpha \times 10^{23} \text{ MeV}$. The value of $\alpha$ is . . . . . . . . . . . (Avogadro Number $= 6 \times 10^{23} \text{ per mole}$)

Statement $1$: Energy is released when a heavy nucleus undergoes fission and when light nuclei undergo fusion.
Statement $2$: For heavy nuclei,the binding energy per nucleon decreases as $Z$ increases. For light nuclei,the binding energy per nucleon increases as $Z$ increases.

$A$ nuclear reactor generates power by fission of ${}_{92}U^{235}$ into two equal fragments of ${}_{46}Pd^{116}$ with the emission of two $\gamma$-rays of $5.2 \text{ MeV}$ each and three neutrons. The average binding energies per nucleon of ${}_{92}U^{235}$ and ${}_{46}Pd^{116}$ are $7.2 \text{ MeV}$ and $8.2 \text{ MeV}$ respectively. The usable energy released per fission event is ......... $\text{MeV}$.

$A$ neutron strikes a ${ }_{92}^{235}U$ nucleus and as a result ${ }_{38}^{93}Kr$ and ${ }_{56}^{140}Ba$ are produced along with: