Energy Levels in Atoms and Line Spectra problem 18

An emission spectrum has emission lines of different colours on a black background. Each line corresponds to one wavelength or frequency. This shows that each line corresponds to a discrete amount of energy according to the formula of energy of a photon, which is given as:

where is Planck's constant and is the frequency.

Since the energy of each line corresponds to the specific energy change between energy levels of electrons in the atom of the element emitting the light, we can therefore conclude that this observation leads to an understanding of the existence of discrete electron energy levels in atoms.