A radioactive nucleus with $Z$ protons and $N$ neutrons emits an $\alpha - $ particle, $2\beta$- particles and $2$ gamma rays. The number of protons and neutrons in the nucleus left after the decay respectively, are
$Z -3, N -1$
$Z -2, N -2$
$Z -1, N -3$
$Z, N -4$
$_{90}^{232}Th$ an isotope of thorium decays in ten stages emitting six $\alpha$-particles and four $\beta$-particles in all. The end product of the decay is
On the bombardment of neutron with Boron. $\alpha$-particle is emitted and product nuclei formed is
List-$I$ shows different radioactive decay processes and List-$II$ provides possible emitted particles. Match each entry in List-$I$ with an appropriate entry from List-$II$, and choose the correct option.
List-$I$ | List-$II$ |
($P$) ${ }_{92}^{238} U \rightarrow{ }_{91}^{234} \mathrm{~Pa}$ | ($1$) one $\alpha$ particle and one $\beta^{+}$particle |
($Q$) ${ }_{82}^{214} \mathrm{~Pb} \rightarrow{ }_{82}^{210} \mathrm{~Pb}$ | ($2$) three $\beta^{-}$particles and one $\alpha$ particle |
($R$) ${ }_{81}^{210} \mathrm{Tl} \rightarrow{ }_{82}^{206} \mathrm{~Pb}$ | ($3$) two $\beta^{-}$particles and one $\alpha$ particle |
($S$) ${ }_{91}^{228} \mathrm{~Pa} \rightarrow{ }_{88}^{224} \mathrm{Ra}$ | ($4$) one $\alpha$ particle and one $\beta^{-}$particle |
($5$) one $\alpha$ particle and two $\beta^{+}$particles |
A nucleus of an element $_{84}{X^{202}}$ emits an $\alpha-$ particle first, a $\beta-$ particle next and then a gamma photon. The final nucleus formed has an atomic number
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