Out of the following which one is not a possible energy for a photon to be emitted by hydrogen atom according to Bohr's atomic model?
- 0.65 eV
- 1.9 eV
- 11.1 eV
- 13.6 eV
Answer
(3) 11.1 eV
Solution
Energy levels of hydrogen: En = - 13.6n2 eV
E1 = -13.6 eV, E2 = -3.4 eV, E3 = -1.51 eV, E4 = -0.85 eV, E = 0
Possible photon energies:
n = 4 → 3: 1.51 - 0.85 = 0.66 eV 0.65 eV
n = 3 → 2: 3.4 - 1.51 = 1.89 eV 1.9 eV
n = ∞ → 1: 13.6 eV
n = 2 → 1 gives 10.2 eV and n = 3 → 1 gives 12.09 eV; no transition gives 11.1 eV.
11.1 eV is not possible.
Answer: (3)