radioactive decay

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Related to Radio activity: half life, artificial radioactivity

radioactive decay

(ray-dee-oh-ak -tiv) The spontaneous transformation of one atomic nucleus into another with the emission of energy. The energy is released in the form of an energetic particle, usually an alpha particle, beta particle (i.e. an electron), or positron, sometimes accompanied by a gamma-ray photon. The unstable isotopes of an element that can undergo such transformations are called radioactive isotopes, or radioisotopes. The emission of a particle from the nucleus of a radioisotope results in the production of an isotope of a different element, as in the beta decay of carbon–14 to nitrogen–14 or the alpha decay of radium–226 to radon–222. The isotope produced is itself often radioactive.

The average time taken for half a given number of nuclei of a particular radioisotope to decay is the half-life of that radioisotope; values range from a fraction of a second to thousands of millions of years. See also radiometric dating.

radioactive decay

[¦rād·ē·ō′ak·tiv di′kā]
(nuclear physics)
The spontaneous transformation of a nuclide into one or more different nuclides, accompanied by either the emission of particles from the nucleus, nuclear capture or ejection of orbital electrons, or fission. Also known as decay; nuclear spontaneous reaction; radioactive disintegration; radioactive transformation; radioactivity.
References in periodicals archive ?
Likewise, Enriquez, Bernabe and Freeman's assessment of radio's development in the Philippines and Forero's of radio activity in Colombia are both excellent.
Hispanic radio activity has caught the attention of Madison Avenue executives who have realized the growing importance of the Spanish-speaking audience.
Dan, who is Seneca, and Mary Lou, who is Anishinaabe, say that the primary motivation behind their radio activity is to sensitize Canadians to Aboriginal forms of expression and to promote symbolic healing among, and social justice for, the Aboriginal population.
Adorno's articulation of a "process of listener awareness that could lead to the destabilization of capitalism as a whole" is what worried program sponsors and made 'radio activity' an important force when radio passivity would have been more convenient for sponsors and ad agencies.
Federal radio activity authorities discontinued their laboratory tests after determining comparatively low levels of uranium in the shells used there.
[Kenneth] Kellermann notes." And indeed they turned out to be, with virtually all classes of galaxies exhibiting some radio activity in their cores.
In other countries, such as Argentina, regulatory loopholes allow for a wide range of radio activity. Low-power micro radio, almost by definition, offers listeners material unavailable through other channels.
The 1950s saw the peak of amateur radio activity. The first amateur radio communication at 35 GHz occurred in July of 1957.

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