radioactive decay
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radioactive decay
the disintegration of the nucleus of an unstable nuclide by the spontaneous emission of charged particles, photons, or both.
radioactive decay
The continual loss of energy by radioactive substances. Disintegration of the nucleus by the emission of alpha, beta, or gamma rays eventually results in the complete loss of radioactivity. The time required for some materials to become stable may be minutes and, for others, thousands of years.
See: half-lifeSee also: decay
radioactive
characterized by radioactivity.
radioactive decay
spontaneous decomposition of the nuclei of the atoms of radioactive substances. Measured as the proportion of the atoms in a radionuclide that decompose per unit of time, usually stated as the half-life of that particular isotope.
radioactive fallout
dissemination of radioactive substances through the atmosphere and deposition on the environment generally; causes radiation injury.
radioactive isotope
radionuclide. A radioactive nuclide, e.g. radioactive iodine or strontium.
radioactive tracer
see radioactive tracer.