According to the Bohr theory, which of the following transitions in the hydrogen atom will give rise to the least energetic photon ?
- n = 6 to n = 1
- n = 5 to n = 4
- n = 6 to n = 5
- n = 5 to n = 3
Answer
(3) n = 6 to n = 5
Solution
For hydrogen atom, E = 13.6 ( 1n12 - 1n22 ) eV
6 1: 11 - 136 = 0.972
5 4: 116 - 125 = 0.0225
6 5: 125 - 136 = 0.0122
5 3: 19 - 125 = 0.0711
∴ The n = 6 to n = 5 transition has the smallest energy gap and gives the least energetic photon.
Answer: (3)