Answer: We can calculate the energy levels of an atom
Step-by-step explanation:
Spectral lines tell us how many different energy levels an atom has, and how far apart those energy levels are spaced.This is possible because spectral lines are the result of an excess (emission lines) or deficiency (absorption lines) of observed photons emitted from certain types of matter. The lines are caused by electrons moving between energy levels within individual atoms. Since each element emits it's own unique spectrum, this means that different types of atoms must have a distinct number of electrons in very particular energy levels.