In this video I will explain the property of the selection rule of a quantum mechanic oscillator. The quantum mechanic oscillator can gain or lose energy by the absorption or emission of a proton. The bottom level or lowest the energy level, E0, is equal to (1/2)(“h” bar)(omega). And the increase in energy from 1 level to the next is exactly 1x(“h” bar)(omega) more than the previous level. Therefore the selection rule places a condition on the amount by which “n” can change when absorbing or emitting energy (photons).