Which of the following is NOT an interaction of beta particles with matter?

• A. Excitation
• B. Ionization
• C. Bremsstrahlung
• D. Nuclear fission

Answer: (D)

Beta radiation interacts with matter mainly through electromagnetic processes with atomic electrons and the nuclear electric field. This includes transferring energy to electrons to cause ionization or excite them to higher energy levels, and producing bremsstrahlung when the fast charged beta particle slows in the strong electric field of nuclei. Nuclear fission, by contrast, is a nuclear reaction in which a heavy nucleus splits into lighter nuclei, driven by the strong force (often triggered by neutrons or high-energy photons). A beta particle does not cause a nucleus to undergo fission in the typical interactions that beta particles undergo as they pass through matter. So nuclear fission is the process that does not describe how beta particles interact with matter.