Talk:Isotopes of helium/Archive 1

Archive 1

Data 2003

This article is part of Wikipedia:Wikiproject Isotopes. Please keep style and phrasings consistent across the set of pages. For later reference and improved reliability, data from all considered multiple sources is collected here. References are denoted by these letters:

• (A) G. Audi, O. Bersillon, J. Blachot, A.H. Wapstra. The Nubase2003 evaluation of nuclear and decay properties, Nuc. Phys. A 729, pp. 3-128 (2003). — Where this source indicates a speculative value, the # mark is also applied to values with weak assignment arguments from other sources, if grouped together. An asterisk after the A means that a comment of some importance may be available in the original.
• (B) National Nuclear Data Center, Brookhaven National Laboratory, information extracted from the NuDat 2.1 database. (Retrieved Sept. 2005, from the code of the popup boxes).
• (C) David R. Lide (ed.), Norman E. Holden in CRC Handbook of Chemistry and Physics, 85th Edition, online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes. — The CRC uses rounded numbers with implied uncertainties, where this concurs with the range of another source it is treated as exactly equal in this comparison.
• (D) More specific level data from reference B's Levels and Gammas database.
• (E) Same as B but excitation energy replaced with that from D.

  Z   N refs symbol   half-life                   spin              excitation energy
  2   1 ABC |He-3    |STABLE                     |1/2+
  2   2 ABC |He-4    |STABLE                     |0+
  2   3 A   |He-5    |700(30)E-24 s              |3/2-
  2   3 BC  |He-5    |[0.60(2) MeV]              |3/2-
  2   4 ABC |He-6    |806.7(15) ms               |0+
  2   5 A   |He-7    |2.9(5)E-21 s [159(28) keV] |(3/2)-
  2   5 BC  |He-7    |[0.15(2) MeV]              |(3/2)-
  2   6 ABC |He-8    |119.0(15) ms               |0+
  2   7 A   |He-9    |7(4)E-21 s [100(60) keV]   |1/2(-#)
  2   7 B   |He-9    |[65(37) keV]               |(1/2-)
  2   7 C   |He-9    |[0.10(6) MeV]              |(1/2-)
  2   8 A   |He-10   |2.7(18)E-21 s              |0+
  2   8 B   |He-10   |[0.17(11) MeV]             |0+
  2   8 C   |He-10   |[0.3(2) MeV]               |0+

Femto 15:43, 19 November 2005 (UTC)

comment

From the description of helium-8: Produced from ⁹He, decomposes to ⁷Li through beta decay then emits a delayed neutron. Strictly speaking, doesn't it decompose first to ⁸Li through the beta decay, and then to ⁷Li by emitting the delayed neutron? —The preceding unsigned comment was added by 144.136.191.193 (talk • contribs) .

5He

The article makes it sound as though 5He was particle-bound. Actually, the half-life is on the order of c/x, where x is the size of the nucleus, so I think it's not particle-bound. IMO the article should make a clearer distinction between particle-bound and particle-unbound nuclei.--76.93.42.50 (talk) 21:00, 29 May 2008 (UTC)