Difference between revisions of "Decay chain"

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(Actinium (4n+3) series)
(Actinium (4n+3) series)
 
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===Actinium  (4''n''+3) series===
 
===Actinium  (4''n''+3) series===
 
{{main|Actinium series}}
 
{{main|Actinium series}}
{| class="wikitable" style="text-align:center;"
 
|-
 
| colspan=4 | [[Uranium-235]]<br/>(α, 7.04{{e|8}} a)
 
|-
 
| colspan=4 | [[Thorium-231]]<br/>(β<sup>−</sup>, 25.52 h)
 
|-
 
| colspan=4 | [[Protactinium-231]]<br/>(α, 3.276{{e|4}} a)
 
|-
 
| colspan=4 | [[Actinium-227]]<br/>(21.772 a)
 
|-
 
| β<sup>−</sup>, 98.62% || colspan=3 | α, 1.38%
 
|-
 
| rowspan=2 | [[Thorium-227]]<br/>(α, 18.68 d) || colspan=3 | [[Francium-223]]<br/>(22.00 min)
 
|-
 
| β<sup>−</sup>, 99.994% || colspan=2 | α, 0.006%
 
|-
 
| colspan=2 rowspan=2 | [[Radium-223]]<br/>(α, 11.43 d) || colspan=2 | [[Astatine-219]]<br/>(56 s)
 
|-
 
| β<sup>−</sup>, 3.00% || α, 97.00%
 
|-
 
| colspan=3 | [[Radon-219]]<br/>(α, 3.96 s) || [[Bismuth-215]]<br/>(β<sup>−</sup>, 7.6 min)
 
|-
 
| colspan=4 | [[Polonium-215]]<br/>(1.781 ms)
 
|-
 
| colspan=2 | α, 99.99977% || colspan=2 | β<sup>−</sup>, 0.00033%
 
|-
 
| colspan=2 | [[Lead-211]]<br/>(β<sup>−</sup>, 36.1 min) || colspan=2 | [[Astatine-215]]<br/>(α, 0.1 ms)
 
|-
 
| colspan=4 | [[Bismuth-211]]<br/>(2.14 min)
 
|-
 
| colspan=2 | α, 99.724% || colspan=2 | β<sup>−</sup>, 0.276%
 
|-
 
| colspan=2 | [[Thallium-207]]<br/>(β<sup>−</sup>, 4.77 min) || colspan=2 | [[Polonium-211]]<br/>(α, 516 ms)
 
|-
 
| colspan=4 | [[Lead-207]]<br/>(STABLE)
 
|}
 
  
 
==Notes and references==
 
==Notes and references==

Latest revision as of 09:57, 18 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.[1] 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.[2] 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,[3][4] Soddy[5][6] and Russell.[7] The original version of the law, which describes the most common forms of radioactive decay, is that

The discovery (1914) of a difference in atomic weight between lead samples from thorium and uranium minerals,[8][9] as predicted by Fajans,[3] was conclusive proof of the corresponding decay chains.[10][11]

Actinoid decay chains

Because alpha decay changes the mass number by four, while beta decay does not change the mass number at all, all the nuclides in a decay chain have the same value of mod 4(A), and the chains can be distinguished as those where A = 4n, or 4n+1, etc. for all the nuclides in the chain.

Thorium (4n) series

Neptunium (4n+1) series

Uranium (4n+2) series

Actinium (4n+3) series

Notes and references

Notes

  1. Jump up This description applies to β decay, which was the only type of beta decay known in 1913.

References

  1. Jump up decay chain, <http://goldbook.iupac.org/D01537.html> (accessed 18 April 2011), Compendium of Chemical Terminology Internet edition; International Union of Pure and Applied Chemistry (IUPAC).
  2. Jump up Seaborg, Glenn T. The Neptunium (4n + 1) Radioactive Family. Chem. Eng. News 1948, 26 (26), 1902–6. DOI: 10.1021/cen-v026n026.p1902.
  3. Jump up to: 3.0 3.1 Fajans, Kasimir Die radioaktiven Umwandlungen und das periodische System der Elemente. Ber. Dtsch. Chem. Ges. 1913, 46, 422–39. DOI: 10.1002/cber.19130460162. Translated excerpt
  4. Jump up Fajans, K. Phys. Z. 1913, 14, 131–36. Fajans, K. Phys. Z. 1913, 14, 136–42. Fajans, K. Radium 1913, 10, 61.
  5. Jump up Soddy, Frederick The Radio-elements and the Periodic Law. Chem. News 1913, 107, 97–99, <http://web.lemoyne.edu/~giunta/soddycn.html>.
  6. Jump up Soddy, Frederick Radioactivity. Annu. Rep. Prog. Chem. 1913, 10, 262–88. DOI: 10.1039/AR9131000262.
  7. Jump up Russell, Alexander S. The periodic system and the radio-elements. Chem. News 1913, 107, 49–52.
  8. Jump up Soddy, Frederick; Hyman, Henry The atomic weight of lead from ceylon thorite. J. Chem. Soc., Trans. 1914, 105, 1402–8. DOI: 10.1039/CT9140501402.
  9. Jump up Richards, Theodore W.; Lembert, Max E. The Atomic Weight of Lead of Radioactive Origin. J. Am. Chem. Soc. 1914, 36 (7), 1329–44. DOI: 10.1021/ja02184a001.
  10. Jump up Anders, Oswald U. The place of isotopes in the periodic table: The 50th anniversary of the Fajans–Soddy displacement laws. J. Chem. Educ. 1964, 41 (10), 522. DOI: 10.1021/ed041p522.
  11. Jump up Kauffman, George B. The atomic weight of lead of radioactive origin: A confirmation of the concept of isotopy and the group displacement laws. Part I. J. Chem. Educ. 1982, 59 (1), 3. DOI: 10.1021/ed059p3. Kauffman, George B. The atomic weight of lead of radioactive origin: A confirmation of the concept of isotopy and the group displacement laws. Part II. J. Chem. Educ. 1982, 59 (2), 119. DOI: 10.1021/ed059p119.

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