Two photons are emitted as an electron de-excites from the third quantum level to the second, and then to the ground state. The sum of the frequencies of the two photons equals the frequency of the single photon that would be emitted if the de-excitation were from the third to the ground state directly. This is according to
A) the physicist W. Ritz.
B) energy conservation.
C) both of these
D) neither of these

Question

Quizplus · Accepted Answer

The principle described is a direct consequence of energy conservation, as the total energy released during the electron's transition must be conserved, whether it occurs in one step or multiple steps. This principle is also in line with the Ritz combination principle, which states that the frequencies of lines in the spectrum of an atom can be expressed as differences between terms that correspond to energy levels, thus supporting the idea that the sum of the frequencies of the two-step transition equals the frequency of the direct transition.

Two Photons Are Emitted as an Electron De-Excites from the Third