Part 6: Spectroscopy

Spectroscopy can be defined as the study of the interaction of electromagnetic radiation with matter. The energy of radiation depends upon its wavelength. Different wavelengths of radiation have different interactions with matter. For example, absorption of a photon in the ultraviolet and visible region may cause an electron to move between the quantized energy levels of the atom or molecule; these are called electronic transitions. Absorption of a photon of UV light may cause an electron to move to a higher energy level. If the electron drops back down to the original level, a photon of the same wavelength will be emitted.