When stable materials become radioactive, what process is occurring?

The correct response identifies the phenomenon known as activation, which refers to the process by which stable materials become radioactive as a result of exposure to a source of radiation or neutrons. This process involves the absorption of neutrons or other particles by a stable nucleus, transforming it into a radioactive isotope.

During activation, stable nuclei can capture incoming particles, making them unstable and causing them to undergo radioactive decay over time. This is distinct from decay itself, which describes the process by which an unstable nucleus breaks down into smaller particles and emits radiation. Thus, while decay can follow activation, it does not describe the initial change from stability to radioactivity.

Radiation refers broadly to the energy emitted during decay processes rather than the process that initiates a stable material’s conversion into a radioactive one. Ionic conversion pertains to changes in the electronic structure of atoms and does not relate to the transformation of stable materials into radioactive forms. Therefore, activation is the most accurate term for describing the transition from a stable to a radioactive state.