Upon ejection the kinetic energy of the Auger electron corresponds to the difference between energy of the initial electronic transition and the ionization energy for the shell from which the Auger electron was ejected. These energy levels depend on the type of atom and the chemical environment in which the atom was located. Thus by monitoring the energy of Auger electrons it is possible to determine the identity of the emitting atom and some information about its environment. This is [Auger electron spectroscopy]?