First Known Use: 1899
Dictionary
radioactivity
noun ra·dio·ac·tiv·i·ty \-ak-ˈti-və-tē\
Definition of RADIOACTIVITY
: the property possessed by some elements (as uranium) or isotopes (as carbon 14) of spontaneously emitting energetic particles (as electrons or alpha particles) by the disintegration of their atomic nuclei; also : the rays emitted
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Origin of RADIOACTIVITY
International Scientific Vocabulary
Rhymes with RADIOACTIVITY
RADIOACTIVITY Defined for Kids
radioactivity
noun ra·dio·ac·tiv·i·ty \ˌrā-dē-ō-ak-ˈti-və-tē\
Definition of RADIOACTIVITY for Kids
1
: the giving off of rays of energy or particles by the breaking apart of atoms of certain elements (as uranium)
2
: the rays or particles that are given off when atoms break apart
Medical Dictionary
radioactivity
noun ra·dio·ac·tiv·i·ty \-ak-ˈtiv-ət-ē\
plural ra·dio·ac·tiv·i·ties
Medical Definition of RADIOACTIVITY
: the property possessed by some elements (as uranium) or isotopes (as carbon 14) of spontaneously emitting energetic particles (as electrons or alpha particles) by the disintegration of their atomic nuclei
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