Question

Question #1bc59

Answer 1

It means that the light must be absorbed or emitted as a single quantum of energy.

Explanation:

For example, the difference between the `n = 2` and `n = 3` levels in the hydrogen atom is `3.03 × 10^"-19" color(white)(l)"J"`.

If an electron drops from level 3 to level 2, the energy must be emitted as a single quantum with energy `3.03 × 10^"-19" color(white)(l)"J"`.

The energy will not be emitted as two quanta with energies `2.00 × 10^"-19" color(white)(l)"J"` and `1.03 × 10^"-19" color(white)(l)"J"` or any other combination of energies.

If an electron jumps from level 2 to level 3, it must absorb a single quantum with energy `3.03 × 10^"-19" color(white)(l)"J"`.

It will not absorb two quanta with energies `1.00 × 10^"-19" color(white)(l)"J"` and `2.03 × 10^"-19" color(white)(l)"J"` or any other combination of energies.