How Do Spectral Lines Reveal Chemical Composition?

Spectral lines are unique fingerprints of elements. When light from a star passes through a prism or diffraction grating, it splits into a spectrum. Each element absorbs and emits light at specific wavelengths, creating distinct lines in the spectrum. By analyzing these lines, scientists can identify the elements present in stars and other celestial objects. This technique, known as spectroscopy, is fundamental in astrophysics.