In general, the photoelectric effect is the most likely interaction to occur within a matter at a lower photon (X-ray) energy range. In this interaction, a photon will transfer its entire energy to an electron in the material on which it impinges. The electron thereby acquires enough energies to free itself from the material to which it is bound and then may undergo single or multiple-scattering events with neighboring atoms. In addition, there is also a slight fluctuation in the probability of emission of Auger electrons and fluorescent photons may form during this interaction. This phenomenon can contribute to the alteration of the mass attenuation coefficient of an element relative to the bulk material when considered over a small range of X-ray energies. The probability of photoelectric interaction is directly proportional to the cube of the atomic number of the absorbing material Z3 and inversely proportional to the cube of the X-ray energy (1/E)3.