What type of photon-electron interaction occurs when a photon transfers all its energy to an electron?

The situation described, where a photon transfers all of its energy to an electron, is indicative of the photoelectric effect. In this interaction, a photon is completely absorbed by an electron in an atom, imparting all of its energy to that electron. This causes the electron to be ejected from the atom, resulting in ionization.

The photoelectric effect is significant because it demonstrates how photons can interact with matter in a way that leads to the absorption of energy, leading to ionization and the generation of secondary electrons. It typically occurs with low-energy photons interacting with tightly bound electrons in inner shells of atoms, where the energy of the photon is sufficient to overcome the binding energy of the electron.

This process is crucial in many applications, including radiation detection and imaging techniques, as it contributes to the understanding of how X-rays and gamma rays interact with matter. The other types of interactions listed, while they involve photon-electron interactions, do not involve the complete transfer of energy from the photon to the electron in the same way.