Difference between revisions of "Decay chain"
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A '''decay chain''', also called a '''radioactive series''', is a sequence of [[nuclide]]s in which each nuclide transforms into the next by [[radioactive decay]] until a stable nuclide is reached. There are three "classical" decay chains, which describe the decay of the naturally-occuring [[actinoid]]s; a fourth long decay chain has become extinct in natural sources, but is known from artificially-produced radionuclides. Shorter decay chains describe the decay of the [[transfermium element]]s and lighter non-actinoid radionuclides. | A '''decay chain''', also called a '''radioactive series''', is a sequence of [[nuclide]]s in which each nuclide transforms into the next by [[radioactive decay]] until a stable nuclide is reached. There are three "classical" decay chains, which describe the decay of the naturally-occuring [[actinoid]]s; a fourth long decay chain has become extinct in natural sources, but is known from artificially-produced radionuclides. Shorter decay chains describe the decay of the [[transfermium element]]s and lighter non-actinoid radionuclides. | ||
| − | The principle of a decay chain comes from the [[radioactive displacement law]], deduced in 1913 by [[Kazimierz Fajans|Fajans]], [[Frederick Soddy|Soddy]] and [[Alexander Russell|Russell]]. The original version of the law, which describes the most common forms of radioactive decay, is that | + | The principle of a decay chain comes from the [[radioactive displacement law]], deduced in 1913 by [[Kazimierz Fajans|Fajans]], [[Frederick Soddy|Soddy]] and [[Alexander Russell|Russell]].<ref>{{citation | first = Alexander S. | last = Russell | authorlink = Alexander Russell | title = The periodic system and the radio-elements | journal = Chem. News | year = 1913 | volume = 107 | pages = 49–52}}.</ref> The original version of the law, which describes the most common forms of radioactive decay, is that |
*[[alpha decay]] leads to a nuclide with an [[atomic number]] two lower than the decaying nuclide, and a [[mass number]] four lower; | *[[alpha decay]] leads to a nuclide with an [[atomic number]] two lower than the decaying nuclide, and a [[mass number]] four lower; | ||
*[[beta decay]]<ref group="note">This description applies to β<sup>−</sup> decay, which was the only type of [[beta decay]] known in 1913.</ref> leads to a nuclide with the same mass number as the decaying nuclide but with an atomic number one higher. | *[[beta decay]]<ref group="note">This description applies to β<sup>−</sup> decay, which was the only type of [[beta decay]] known in 1913.</ref> leads to a nuclide with the same mass number as the decaying nuclide but with an atomic number one higher. | ||
Revision as of 18:26, 17 April 2011
A decay chain, also called a radioactive series, is a sequence of nuclides in which each nuclide transforms into the next by radioactive decay until a stable nuclide is reached. There are three "classical" decay chains, which describe the decay of the naturally-occuring actinoids; a fourth long decay chain has become extinct in natural sources, but is known from artificially-produced radionuclides. Shorter decay chains describe the decay of the transfermium elements and lighter non-actinoid radionuclides.
The principle of a decay chain comes from the radioactive displacement law, deduced in 1913 by Fajans, Soddy and Russell.[1] The original version of the law, which describes the most common forms of radioactive decay, is that
- alpha decay leads to a nuclide with an atomic number two lower than the decaying nuclide, and a mass number four lower;
- beta decay[note 1] leads to a nuclide with the same mass number as the decaying nuclide but with an atomic number one higher.
Actinoid decay chains
Actinium (4n+3) series
| Uranium-235 (α, 7.04 × 108 a) | |
| Thorium-231 (β−, 25.52 h) | |
| Protactinium-231 (α, 3.276 × 104 a) | |
| Actinium-227 (21.772 a) | |
| α, 1.38% | β−, 98.62% |
| Francium-223 (22.00 min) |
Thorium-227 (α, 18.68 d) |
Notes and references
Notes
- ↑ This description applies to β− decay, which was the only type of beta decay known in 1913.
References
- ↑ Russell, Alexander S. The periodic system and the radio-elements. Chem. News 1913, 107, 49–52.
External links
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See also the corresponding article on Wikipedia. |
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