Which description best defines bremsstrahlung?

• A. A breakdown product of alpha particles
• B. An X-ray produced by beta particles when they decelerate
• C. A subatomic particle that is positively charged
• D. An alpha-emitting radioisotope

Answer: (B)

Bremsstrahlung is the X-ray radiation produced when fast charged particles are slowed or deflected by the electric field of atomic nuclei. In practice, when beta particles (electrons) move through matter or strike an X-ray tube target, their rapid deceleration emits X-ray photons. This is why describing it as an X-ray produced by beta particles when they decelerate fits bremsstrahlung. The other options point to nuclear decay products, a positively charged subatomic particle, or an alpha-emitting isotope, none of which describe the braking radiation process.