a radioactive process in which an alpha particle is emitted from the nucleus of an atom, decreasing its atomic number by two.
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British Dictionary definitions for alpha decay
the radioactive decay process resulting in emission of alpha particles
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 alpha decay
The radioactive decay of an atomic nucleus by emission of an alpha particle (two protons bound to two neutrons). When an element undergoes alpha decay, its atomic number decreases by two.
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