Which statement about ionizing and non-ionizing radiation is true?

• A. Non-ionizing radiation has enough energy to eject electrons.
• B. Ionizing radiation has enough energy to remove bound electrons; non-ionizing does not.
• C. Both ionizing and non-ionizing radiation remove electrons.
• D. Non-ionizing radiation always increases electron binding energy.

Answer: (B)

Ionization happens when a photon delivers enough energy to overcome the electron’s binding energy. Ionizing radiation carries photons with energy at or above that threshold, so it can eject a bound electron. Non-ionizing radiation, with energy below that threshold, can raise an electron to a higher bound state (excitation) or simply heat the material, but it cannot remove the electron. So the statement that ionizing radiation has enough energy to remove bound electrons while non-ionizing does not is the true one.