Binding energy of a hydrogen atom is $13.6 \ eV$. The binding energy of a singly ionized helium atom is : ............ $eV$

What is the energy (in $J$ atom$^{-1}$) required for the following process?
$Li^{2+}(g) \to Li^{3+}(g) + e^-$
(Take the ionization energy for the $H$ atom in the ground state as $2.18 \times 10^{-18}$ $J$ atom$^{-1}$)

What is the angular momentum of an electron in the orbit of an $H$ atom where the energy of the electron is $-3.4 \ eV$?

The ionization energy of a hydrogen atom is $13.6 \ eV$. The energy required to ionize a hydrogen atom in its second excited state is ........... $eV$.

The ratio of the energy of a photon of $2000 \ \mathring{A}$ wavelength radiation to that of $4000 \ \mathring{A}$ radiation is

The magnitude of kinetic energy $(K.E.)$ of an electron in a Bohr orbit is equal to which of the following?