Why scientists care
Spectroscopy studies how matter emits, absorbs or scatters electromagnetic radiation as a function of wavelength, frequency or energy.
Spectra act like structured fingerprints: their lines and bands reveal energy levels, composition and molecular structure.
A concrete example
Hydrogen emits discrete spectral lines because electrons change between quantized energy states.
Try to notice
Science becomes memorable when a definition is connected to something measurable or observable.