$$ { }_{82}^{290} X \xrightarrow{\alpha} Y \xrightarrow{e^{+}} Z \xrightarrow{\beta^{-}} P \xrightarrow{e^{-}} Q $$

In the nuclear emission stated above, the mass number and atomic number of the product $$Q$$ respectively, are

The ground state energy of hydrogen atom is $$-13.6 ~\mathrm{eV}$$. The energy needed to ionize hydrogen atom from its second excited state will be :

The wavelength of Lyman series of hydrogen atom appears in:

The angular momentum of an electron moving in an orbit of hydrogen atom is $$\mathrm{1.5\left(\frac{h}{\pi}\right)}$$. The energy in the same orbit is nearly.