Which type of radiation produces photons with discrete energies corresponding to atomic transitions?

• A. Bremsstrahlung
• B. Photoelectric
• C. Characteristic
• D. Compton

Answer: (C)

Energy comes in discrete amounts when electrons in an atom move between fixed energy levels. Characteristic radiation is produced when an inner-shell vacancy is created and an electron from a higher level fills it, emitting a photon whose energy equals the exact difference between those two energy levels. That yields photons with specific, element-dependent energies (line spectra such as Kα, Kβ, etc.).

Bremsstrahlung, in contrast, comes from the deceleration of a charged particle and spans a continuous range of energies. The photoelectric effect involves photon absorption to eject an electron, not emitting a photon with a fixed energy. Compton scattering changes photon energy depending on the scattering angle, also not discrete.