Radioactivity

Noun

 * 1) Spontaneous emission of ionizing radiation as a consequence of a nuclear reaction, or directly from the breakdown of an unstable nucleus.
 * 2) The radiation so emitted; including gamma rays, alpha particles, neutrons, electrons, positrons, etc.

Related terms

 * radiation

Thesaurus
activity, artificial radioactivity, contamination, curiage, decontamination, fallout, half-life, natural radioactivity, nuclear radiation, radiant energy, radiation, radioactive radiation, radiocarbon dating, radiolucency, radiopacity, radiosensibility, radiosensitivity, saturation point, specific activity