The emission of subatomic particles from an unstable atomic nuclei. Nuclear radiation, or radioactive decay, was first discovered in 1896 by the French scientist Henri Becquerel while working on phosphorescent materials. Researchers soon learned that an electric or magnetic field split emissions into three beams, which were given the alphabetic names alpha, beta, and gamma. The direction of electromagnetic forces indicated that alpha rays carried a positive charge, beta rays carried a negative charge, and gamma rays were neutral. The SI unit for measuring radioactive decay is the becquerel (Bq) where one decay event per second, has an activity of one Bq.
Synonyms and Related Terms
atomic energy; nuclear energy; nuclear power; radioactive decay; alpha particles; alpha rays; beta particles; beta rays; gamma particles; ramma rays