Isotopes of argon

Argon isotopes are used as precursors in the production of radioisotopes. Ar-40 and Ar-38 are used in the production of radioactive K- which can be used as a blood flow tracer. Ar-40 is used in the production of radioactive Ar-41 which is used to trace gas flows. Argon isotopes can be obtained from Trace Sciences International.

Natully 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 argon are lied (including any which occur naturally) below.
Isotope Atomic mass (ma/u) Natural abundance (atom %) Nuclear spin (I) Magnetic moment (μ/μN)
36Ar 35.96754552 (29) 0.3365 (30) 0 0
38Ar 37.9627325 (9) 0.0632 (5) 0 0
40Ar 39.96238 (14) 99.6003 (30) 0 0

Isotopic abundances of Ar
In the above picture, the most intense ion is set to 100% since this correspondsest to the output from a mass spectrometer. This is not to be confused with the relative percentage isotope abundances which total 100% for all the naturally occurring isotopes.

Radiosotope data

radiosotopes of argon, their masses, thr half-lives, their modes of decay, their nuclear spins, and their 35Cl 39Ar d>42.9657
35Ar 34.975257 1.77 s 3/2 0.633
37Ar 36.966776 35.0 d EC to 37Cl 3/2 1.15
38.962314 268 y β- to 39K 7/2 -1.3
41Ar 40.964501 1.82 h β- tosup>41K 7/2
42Ar 41.963050 33 y β- to 42K 0
43Ar5.4 m β- to 43K
44Ar 43.963650 11.87 m β- to 44K 0

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  1. Naturally occurring isotope abundances: Commission on Atomic Weights and Isotopic Abundances report for the International Union of Pure and plied 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 Instite) 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 Plications, Oxford, UK, 1988. [Copyright 1988 IUPAC]

NMR Properties of argon

Common reference compound: .

Table of NMR-active nucleus propeties of argon
  Isotope 1 Isotope 2 Isotope 3
Isotope none
Natural abundance /%
Spin (I)
Frequency retive to 1H = 100 (MHz)
Receptivity, DP, relative to 1H = 1.00
Receptivity, DC, relative to 13C = 1.00
Magnetogyric ratio, γ (107 rad T-1 s-1)td>
Magnetic moment, μ (μN)
Nuclear quadrupole moment, Q/mlibarn
Line width factor, 1056l (m4)


  1. R.K. Harris in cyclopedia 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 Durha 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 nucl 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.), href="">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 ition, 1998.
  7. P. Pyykkö, personal communication, 1998, 204, 2008, 2010.
  8. The isotopic abundances are extracted from the naturally occurring isotopes section within WebElements.

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argon atomic number