In a radioactive decay, neither the atomic number nor the mass number changes. Which of the following would be emitted in the decay process

On the bombardment of neutron with Boron. $\alpha$-particle is emitted and product nuclei formed is

The isotope ${ }_5^{12} \mathrm{~B}$ having a mass $12.014 \mathrm{u}$ undergoes $\beta$-decay to ${ }_6^{12} \mathrm{C} .{ }_6^{12 .}$ has an excited state of the nucleus $\left({ }_6^{12} \mathrm{C}^*\right)$ at $4.041 \mathrm{MeV}$ above its ground state. If ${ }_5^{12} \mathrm{~F}$ decays to ${ }_6^{12} \mathrm{C}^*$, the maximum kinetic energy of the $\beta$-particle in units of $\mathrm{MeV}$ is ( $1 \mathrm{u}=931.5 \mathrm{MeV} / c^2$, where $c$ is the speed of light in vacuum).

In the given nuclear reaction, the element $X$ is :

${ }_{11}^{22} Na \rightarrow X + e ^{+}+v$

The $\alpha$-particle is the nucleus of an atom of

A nucleus of an element ${}_{84}{X^{202}}$ emits an $\alpha $-particle first, $\beta $ -particle next and then a gamma photon. The final nucleus formed has an atomic number