โ–ธโ–ธ
  • ๐Ÿ‡ฌ๐Ÿ‡ง Helium
  • ๐Ÿ‡บ๐Ÿ‡ฆ ะ“ะตะปั–ะน
  • ๐Ÿ‡จ๐Ÿ‡ณ ๆฐฆ
  • ๐Ÿ‡ณ๐Ÿ‡ฑ Helium
  • ๐Ÿ‡ซ๐Ÿ‡ท Hélium
  • ๐Ÿ‡ฉ๐Ÿ‡ช Helium
  • ๐Ÿ‡ฎ๐Ÿ‡ฑ ื”ืœื™ื•ื
  • ๐Ÿ‡ฎ๐Ÿ‡น Elio
  • ๐Ÿ‡ฏ๐Ÿ‡ต ใƒ˜ใƒชใ‚ฆใƒ 
  • ๐Ÿ‡ต๐Ÿ‡น Hélio
  • ๐Ÿ‡ช๐Ÿ‡ธ Helio
  • ๐Ÿ‡ธ๐Ÿ‡ช Helium
  • ๐Ÿ‡ท๐Ÿ‡บ ะ“ะตะปะธะน

Helium - 2He: isotope data

Helium has two isotopes but it consists almost entirely of He-4 with natural He only containing just over 0.0001% of He-3. Thousands of liters of He-3 are used annually in cryogenic applications and He-3 is also used as a neutron counter in nuclear application. He-3 is also applied in magnetic resonance imaging.

Naturally occurring isotopes

This table shows information about naturally occuring isotopes, their atomic masses, their natural abundances, their nuclear spins, and their magnetic moments. Further data for radioisotopes (radioactive isotopes) of helium are listed (including any which occur naturally) below.
Isotope Mass / Da Natural abundance (atom %) Nuclear spin (I) Magnetic moment (μ/μN)
3He 3.016 029 309 7(9) 0.000137 (3) 1/2 -2.127624
4He 4.002 603 2497(10) 99.999863 (3) 0 0
Isotope abundances of helium
Isotope abundances of helium. In the above, the most intense ion is set to 100% since this corresponds best to the output from a mass spectrometer. This is not to be confused with the relative percentage isotope abundances which totals 100% for all the naturally occurring isotopes.

Radiosotope data

Further data for naturally occuring isotopes of helium are listed above. This table gives information about some radiosotopes of helium, their masses, their half-lives, their modes of decay, their nuclear spins, and their nuclear magnetic moments.
Isotope Mass / Da Half-life Mode of decay Nuclear spin Nuclear magnetic moment
6He 6.018886 0.807 s β- to 6Li 3/2
8He 8.03392 0.119 s β- to 8Li; β- + n to 7Li 3/2

References

  1. Naturally occurring isotope abundances: Commission on Atomic Weights and Isotopic Abundances report for the International Union of Pure and Applied Chemistry in Isotopic Compositions of the Elements 1989, Pure and Applied Chemistry, 1998, 70, 217. [Copyright 1998 IUPAC]
  2. For further information about radioisotopes see Jonghwa Chang's (Korea Atomic Energy Research Institute) Table of the Nuclides
  3. Masses, nuclear spins, and magnetic moments: I. Mills, T. Cvitas, K. Homann, N. Kallay, and K. Kuchitsu in Quantities, Units and Symbols in Physical Chemistry, Blackwell Scientific Publications, Oxford, UK, 1988. [Copyright 1988 IUPAC]

NMR Properties of helium

Common reference compound: helium gas.

Table of NMR-active nucleus propeties of helium
  Isotope 1 Isotope 2 Isotope 3
Isotope 3He
Natural abundance /% 0.000137
Spin (I) 1/2
Frequency relative to 1H = 100 (MHz) 76.179437
Receptivity, DP, relative to 1H = 1.00 0.000000606
Receptivity, DC, relative to 13C = 1.00 0.00356
Magnetogyric ratio, γ (107 rad T‑1 s-1) -20.3801587
Magnetic moment, μ (μN) -3.685154336
Nuclear quadrupole moment, Q/millibarn -
Line width factor, 1056 l (m4) -

References

  1. R.K. Harris in Encyclopedia of Nuclear Magnetic Resonance, D.M. Granty and R.K. Harris, (eds.), vol. 5, John Wiley & Sons, Chichester, UK, 1996. I am grateful to Professor Robin Harris (University of Durham, UK) who provided much of the NMR data, which are copyright 1996 IUPAC, adapted from his contribution contained within this reference.
  2. J. Mason in Multinuclear NMR, Plenum Press, New York, USA, 1987. Where given, data for certain radioactive nuclei are from this reference.
  3. P. Pyykkö, Mol. Phys., 2008, 106, 1965-1974.
  4. P. Pyykkö, Mol. Phys., 2001, 99, 1617-1629.
  5. P. Pyykkö, Z. Naturforsch., 1992, 47a, 189. I am grateful to Professor Pekka Pyykkö (University of Helsinki, Finland) who provided the nuclear quadrupole moment data in this and the following two references.
  6. D.R. Lide, (ed.), CRC Handbook of Chemistry and Physics 1999-2000 : A Ready-Reference Book of Chemical and Physical Data (CRC Handbook of Chemistry and Physics, CRC Press, Boca Raton, Florida, USA, 79th edition, 1998.
  7. P. Pyykkö, personal communication, 1998, 204, 2008, 2010.