Frequency of revolution of an electron revolving in $$n$$th orbit of $$\mathrm{H}$$-atom is proportional to

A hydrogen atom is ground state absorbs $$10.2 \mathrm{~eV}$$ of energy. The orbital angular momentum of the electron is increased by

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