In the following nuclear reaction,$x$ stands for: $n \rightarrow p + e^{-} + x$

Assertion : The ionising power of $\beta$-particle is less compared to $\alpha$-particles but their penetrating power is more.
Reason : The mass of $\beta$-particle is less than the mass of $\alpha$-particles.

The radioactive nucleus $_7N^{13}$ decays to $_6C^{13}$ through the emission of

Neutrino is a particle which $\qquad$

Which of the following can pass through $20 \, cm$ thickness of steel?

The end product of the decay of $ { }_{90} Th^{232} $ is $ { }_{82} Pb^{208} $. The number of $ \alpha $ and $ \beta $ particles emitted are respectively: