The energy required to knock out the electron in the third orbit of a hydrogen atom is equal to

The energy of an electron in an orbit of an $H$-atom is:

The energy of a hydrogen atom in its ground state is $-13.6 \ eV$. The energy of the level corresponding to the quantum number $n = 2$ (first excited state) in the hydrogen atom is......$eV$.

The energy required to remove an electron from the $n = 10$ state of a hydrogen atom is ....... (in $, eV$)

$A$ hydrogen atom at the ground level absorbs a photon and is excited to $n=4$ level. The potential energy of the electron in the excited state is

The total energy of an electron in the ground state of a hydrogen atom is $-13.6 \text{ eV}$. The kinetic energy of an electron in the first excited state is.....$\text{ eV}$