Calculate the wavelength, in nanometers, of the light emitted by a hydrogen atom when its electron falls from the n = 7 to the n = 4 principal energy level.

The wavelength of the light emitted by a hydrogen atom for the given transition is 2166 nm.

Explanation:

The energy of nth energy levels of the H atom is given as:

Energy of the seventh energy level =

Energy of the seventh energy level =

Energy of the light emitted will be equal to the energy difference of the both levels.

Wavelength corresponding t