Question

According to Bohr theory, which of the following transitions in the hydrogen atom will give rise to the least energetic photon? Explain also?

1.)n=6 to n=5. 2.)n=5 to n=4

Answer 1

The electron near the nucleus has more energy than the electron at a distance from the nucleus. Due to this the energy of the orbits and thus the energy difference between the orbits decreases on moving farther from the nucleus. Hence, for the given set of transitions, the transition from n = 6 to n = 5 will give rise to the least energetic photon.