radioactivity
the phenomenon, exhibited by and being a property of certain elements, of spontaneously emitting radiation resulting from changes in the nuclei of atoms of the element.
Origin of radioactivity
1- Also called activity.
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British Dictionary definitions for radioactivity
/ (ˌreɪdɪəʊækˈtɪvɪtɪ) /
the spontaneous emission of radiation from atomic nuclei. The radiation can consist of alpha, beta, and gamma radiation
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Scientific definitions for radioactivity
[ rā′dē-ō-ăk-tĭv′ĭ-tē ]
The emission of radiation by unstable atomic nuclei undergoing radioactive decay.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Cultural definitions for radioactivity
The emission of elementary particles by some atoms when their unstable nuclei disintegrate (see half-life). Materials composed of such atoms are radioactive. (See alpha radiation, beta radiation, and gamma radiation.)
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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