What is the energy of a hydrogen atom in the first excited state if the potential energy is taken to be zero in the ground state?

Answer

B, C

Explanation

The potential energy of a hydrogen atom is zero in ground state.
an electron is board to the nucleus with energy `13.6 eV`. Then we have to give `13.6 eV` energy to cancel that energy.
Additional energy `=10.2 eV`.
:. Total energy of an atom in the first excitation state `= 13.6 eV + 10.2 eV`
`=23.8 eV`