Describe how hydrogen Balmer lines are produced in the spectrum of a star

Light of all wavelengths is emitted from the star’s black body surface. Em radiation from the star is absorbed by elements in its atmosphere. Exciting them from the n=1 to n=2 state. A certain frequency of light is needed to excite each element, E=hf. These frequencies are thus missing from the spectrum. The hydrogen Balmer lines are the black lines on the spectrum which correspond to elements in the atmosphere of the star