The minimum frequency of a photon required to break a particle of mass $15.348 \ amu$ into $4 \ \alpha$ particles is . . . . . . $kHz$.
[Mass of $He$ nucleus = $4.002 \ amu$, $1 \ amu = 1.66 \times 10^{-27} \ kg$, $h = 6.6 \times 10^{-34} \ J \cdot s$ and $c = 3 \times 10^8 \ m/s$]

Suppose a ${ }_{88}^{226} Ra$ nucleus at rest and in the ground state undergoes $\alpha$-decay to a ${ }_{86}^{222} Rn$ nucleus in its excited state. The kinetic energy of the emitted $\alpha$ particle is found to be $4.44 \text{ MeV}$. The ${ }_{86}^{222} Rn$ nucleus then goes to its ground state by $\gamma$-decay. The energy of the emitted $\gamma$-photon is . . . . . . . $\text{keV}$.
[Given: atomic mass of ${ }_{88}^{226} Ra = 226.005 \text{ u}$,atomic mass of ${ }_{86}^{222} Rn = 222.000 \text{ u}$,atomic mass of $\alpha$ particle $= 4.000 \text{ u}$,$1 \text{ u} = 931 \text{ MeV}/c^2$]

The energy released in an atom bomb is obtained from?

Fission of nuclei is possible because the binding energy per nucleon in them

In an atomic bomb,the energy is released due to

Match the nuclear processes given in column $I$ with the appropriate option$(s)$ in column $II$.

Column $I$	Column $II$
$A$. Nuclear fusion	$P$. Absorption of thermal neutrons by ${}_{92}^{235}U$
$B$. Fission in a nuclear reactor	$Q$. ${}_{27}^{60}Co$ nucleus
$C$. $\beta$-decay	$R$. Energy production in stars via hydrogen conversion to helium
$D$. $\gamma$-ray emission	$S$. Heavy water
	$T$. Neutrino emission