Isotopes of arsenic

Isotope data

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 arsenic are listed (including any which occur naturally) below.
Isotope Atomic mass (ma/u) Natural abundance (atom %) Nuclear spin (I) Magnetic moment (μ/μN)
75As 74.9215942 (17) 100 3/2 1.43947

Isotopic abundances of As
In the above picture, 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 total 100% for all the naturally occurring isotopes.

Radiosotope data

Further data for naturally occuring isotopes of arsenic are listed above. This table gives information about some radiosotopes of arsenic, their masses, their half-lives, their modes of decay, their nuclear spins, and their nuclear magnetic moments.
Isotope Mass Half-life Mode of decay Nuclear spin Nuclear magnetic moment
68As 67.9368 2.53 m EC to 68Ge 3
69As 68.93228 15.2 m EC to 69Ge 5/2 1.2
70As 69.93093 52.6 m EC to 70Ge 4 2.1061
71As 70.927114 2.72 d EC to 71Ge 5/2 1.6735
72As 71.926753 26.0 h EC to 72Ge 2 -2.1566
73As 72.923825 80.3 d EC to 73Ge 3/2
74As 73.923829 17.78 d β- to 74Se; EC to 74Ge 2 -1.597
76As 75.922394 26.3 h β- to 76Se 2 -0.906
77As 76.920648 38.8 h β- to 77Se 3/2
78As 77.92183 1.512 h β- to 78Se 2
79As 78.92095 9.0 m β- to 79Se 3/2

Sheffield ChemPuter isotope pattern calculator

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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]

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arsenic atomic number