Kirchhoff’s Laws
		Relate continuous spectra, emission line spectra, &                        absorption line spectra 1. Luminous solid (dense gas) emits light of all wavelengths  continuous spectrum of radiation 2. Low density hot gas emits spectrum of bright emission lines  composition of gas 3. Low density cool gas absorbs wavelengths from continuous spectrum  dark absorption lines on continuous spectrum (wavelengths same as emission lines from hot gas)