Which type of x-ray photon is created when an outer-shell electron fills the void of an ejected inner-shell electron?

When an outer-shell electron fills the void left by an ejected inner-shell electron, a characteristic photon is created. This process occurs during a phenomenon called characteristic radiation, which typically happens in the context of x-ray production.

When an inner-shell electron is ejected from an atom due to interaction with incoming x-ray radiation, it leaves a vacancy in that inner shell. An outer-shell electron can then fall into the lower energy level, and as it does so, it releases energy in the form of an x-ray photon. The energy of this characteristic photon corresponds to the difference in energy levels between the two shells involved. This is specific to the energy levels of the particular element, hence the term "characteristic."

In contrast, bremsstrahlung photons result from the deceleration of electrons as they are deflected by the nucleus of an atom, which is a different mechanism from electron transitions between shells. Ionization refers to the process of removing an electron from an atom but does not specifically describe the emission of x-ray photons. Scattered photons arise from changes in direction of photons when they interact with matter, without necessarily being emitted from electronic transitions. Hence, the creation of a characteristic photon is a distinct process that arises specifically from the transition between electron