Radioactivity: Difference between revisions

Latest revision as of 03:51, 27 March 2024

The spontaneous transition of an atomic nucleus to a lower energy state (radioactive decay) accompanied by the emission of an alpha particle, a beta particle, or gamma radiation.
Alpha emission results in a reduction of atomic number by two and mass number by four; (negative) beta emission results in an increase of atomic number by one but no change in mass number; in gamma emission, atomic number and mass number are unchanged. Several naturally occurring isotopes are radioactive, including carbon-14 and potassium-40, which reside in the human body. Radon (strictly, radon-222) is a natural radioactive gas originating ultimately from the radioactive decay of uranium-238. Artificial radioactivity, as opposed to natural radioactivity, is a consequence of bombardment of isotopes that are not radioactive with neutrons, protons, and other subatomic particles.
See half-life.
(Often simply activity.) Rate of decay of a radioactive isotope.
The unit of radioactivity is the curie.

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+#The spontaneous transition of an atomic [[nucleus]] to a lower [[energy]] state (radioactive  decay) accompanied by the [[emission]] of an [[alpha particle]], a [[beta particle]], or [[gamma ray|gamma  radiation]].<br/> Alpha emission results in a reduction of [[atomic number]] by two and mass number by four;  (negative) beta emission results in an increase of atomic number by one but no change in mass  number; in gamma emission, atomic number and mass number are unchanged. Several naturally  occurring [[isotopes]] are radioactive, including carbon-14 and potassium-40, which reside in the  human body. [[radon|Radon]] (strictly, radon-222) is a natural [[radioactive gas]] originating ultimately from  the radioactive decay of uranium-238. Artificial radioactivity, as opposed to natural radioactivity,  is a consequence of bombardment of isotopes that are not radioactive with [[neutrons]], [[protons]],  and other subatomic particles. <br/>''See'' [[half-life]].<br/>
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+#(Often simply activity.) Rate of decay of a radioactive [[isotope]].<br/> The unit of radioactivity is the [[curie]].
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-#<div class="definition"><div class="short_definition">The spontaneous transition of an atomic [[nucleus]] to a lower [[energy]] state (radioactive  decay) accompanied by the [[emission]] of an [[alpha particle]], a [[beta particle]], or [[gamma ray|gamma  radiation]].</div><br/> <div class="paragraph">Alpha emission results in a reduction of [[atomic number]] by two and mass number by four;  (negative) beta emission results in an increase of atomic number by one but no change in mass  number; in gamma emission, atomic number and mass number are unchanged. Several naturally  occurring [[isotopes]] are radioactive, including carbon-14 and potassium-40, which reside in the  human body. [[radon|Radon]] (strictly, radon-222) is a natural [[radioactive gas]] originating ultimately from  the radioactive decay of uranium-238. Artificial radioactivity, as opposed to natural radioactivity,  is a consequence of bombardment of isotopes that are not radioactive with [[neutrons]], [[protons]],  and other subatomic particles. <br/>''See'' [[half-life]].</div><br/> </div>
-#<div class="definition"><div class="short_definition">(Often simply activity.) Rate of decay of a radioactive [[isotope]].</div><br/> <div class="paragraph">The unit of radioactivity is the [[curie]].</div><br/> </div>
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