Which of the following terms refers to particles or rays emitted during the decay of a radionuclide?

The term that refers to particles or rays emitted during the decay of a radionuclide is radiation. Radiation encompasses various types of emissions, including alpha particles, beta particles, and gamma rays, which are released as certain unstable isotopes transform into more stable forms. This process is a natural part of radioactive decay and is what allows us to measure and assess the presence of radionuclides in different environments, particularly in the context of radon exposure.

The other terms are related but do not directly define the emissions themselves. Ionization refers to the process of gaining or losing electrons and converting atoms into ions, often as a result of exposure to radiation. Fusion is a nuclear process that combines light atomic nuclei into heavier nuclei, releasing energy but not referring to the decay of radionuclides. The decay constant specifically relates to the rate at which a radionuclide decays, rather than the particles or rays emitted during that decay. Understanding these distinctions is crucial for those involved in radon measurement and radiation safety.