The excitation potential of hydrogen atom in the first excited state is

Options

(a) 13.6 V
(b) (-13.6 V)
(c) 10.2 V
(d) (-10 V)

Correct Answer:

10.2 V

Explanation:

Energy of electron in ground state of hydrogen atom,
E₁ = -1.36 eV [E(n) = (-13.6 / n²) eV]
Energy of electron in first excited state of hydrogen atom,
E₂ = -13.6 / 2² = – 3.4 eV
Hence, the excitation energy of hydrogen atom in first excited state,
E = E₂ – E₁ = – 3.4 – (-13.6) = 10.2 eV
Therefore, excitation potential is 10.2 V.