Spectra can be obtained from interactions between electromagnetic radiation of certain wavelengths and electrons in orbitals of an atom. These interactions produce emission spectra if large amounts of energy excite electrons in the atoms. The energy coming from a flame or some other energy source. When they lose their excitation energy, some of these atoms emit discrete raditation while returning to a less energetic state. Absorption of spectra occurs if the interactions cause a decrease in the intensity of the radiation due to electronic excitation. The emission or absorption of energy corresponds to an electronic orbital transition in an atom in Atomic spectrum.
The Guide To Acing Physical Pharmacy