Which process involves the ejection of an electron from its bound state?

The process that involves the ejection of an electron from its bound state is photoelectric absorption. In this interaction, a photon interacts with an atom and transfers all of its energy to an electron within one of the atom's inner shells. If the energy of the photon is greater than the binding energy of the electron, the electron is completely ejected from the atom, resulting in ionization of the atom. This is a key concept in understanding how radiation interacts with matter, especially in the context of radiation safety and the mechanisms by which biological tissues can be affected by radiation exposure.

Compton scattering involves the scattering of a photon and does not result in the complete ejection of an electron from its bound state but rather involves the energy transfer of part of the photon to an electron that is loosely bound. Pair production refers to the conversion of a photon into a particle-antiparticle pair, but it occurs only at very high energies and does not involve ejecting a bound electron. Rayleigh scattering is an elastic scattering of photons by particles, which does not affect the bound state of electrons at all. Therefore, photoelectric absorption is specifically the process that describes the ejection of an electron from an atom’s bound state.