The electronic energy levels of the hydrogen atom in the Bohr's theory are called

The angular momentum of an electron in the $7^{th}$ Bohr orbit of a hydrogen atom is given by:

The energy of an electron in the first orbit of a hydrogen atom is $-13.6 \ eV$. The possible energy value for an electron in the excited state is ............ $eV$.

The radii of the first Bohr orbit of $H$ $(r_{H})$,$He^{+}$ $(r_{He^{+}})$ and $Li^{2+}$ $(r_{Li^{2+}})$ are in the order

One energy difference between the states $n = 2$ and $n = 3$ is $E \ eV$,in a hydrogen atom. The ionization potential of the $H$ atom is ............. $E$.

The frequency and energy of a photon with a wavelength of $4000 \ \mathring{A}$ are respectively.......