Absorption spectroscopy refers to spectroscopic techniques that measure the absorption of radiation, as a function of frequency or wavelength, due to its interaction with a sample.
The Compton wavelength is a quantum mechanical property of a particle.
The ionization energy (Ei) is qualitatively defined as the amount of energy required to remove the most loosely bound electron, the valence electron, of an isolated gaseous atom to form a cation.
K-edge is the binding energy of the K-shell (innermost, using X-ray notation) electron of an atom.
Molecular electronic transitions take place when electrons in a molecule are excited from one energy level to a higher energy level.The energy change associated with this transition provides information on the structure of a molecule and determines many molecular properties such as color.