Which phenomenon describes the process where electrons are emitted from matter?

The phenomenon that describes the process where electrons are emitted from matter is the photoelectric effect. This effect occurs when light (or more generally, electromagnetic radiation) interacts with matter, leading to the ejection of electrons from a material. In this process, photons strike the surface of a material and transfer enough energy to an electron, overcoming the binding energy that holds the electron within the atom. When the energy of the incoming photon exceeds the work function of the material, the electron is emitted.

This concept is crucial in various fields, including physics and medical imaging, as it helps to understand how ionizing radiation interacts with tissues and imaging detectors. The photoelectric effect is also foundational in explaining phenomena in quantum mechanics, where light exhibits both wave-like and particle-like characteristics.

Other phenomena mentioned—such as pair production, which refers to the creation of an electron-positron pair from the energy of a photon in a strong electromagnetic field, or bremsstrahlung, which involves the radiation of energy by charged particles when they are accelerated, mainly through interaction with other charged particles—do not describe the emission of electrons from matter in the same way as the photoelectric effect. Moreover, electron capture describes a process in which an electron is absorbed by a proton in a