Isotopes of selenium

Isotope data
selenium symbol icon

Selenium isotopes are mainly used for the production of medical and industrial radioisotopes. Se-77 and Se-78 are used for the production of the therapeutic radioisotope Br-77. Se-80 is used for the production of the medical radioisotope Br-80m. Se-74 is used for the production of Se-75 which is used as a source in gamma radiography. Se-76 can be used for the production of the medical isotopes Br-75 and Br-76. Se-82 has been used to study double beta decay. Most of the Selenium isotopes have been used in studies into the role of Selenium as an essential nutrient. Selenium isotopes can be obtained from Trace Sciences International.

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 selenium are listed (including any which occur naturally) below.
Isotope Atomic mass (ma/u) Natural abundance (atom %) Nuclear spin (I) Magnetic moment (μ/μN)
74Se 73.9224746 (16) 0.89 (4) 0
76Se 75.9192120 (16) 9.37 (29) 0
77Se 76.9199125 (16) 7.63 (16) 1/2 0.53506
78Se 77.9173076 (16) 23.77 (28) 0
80Se 79.9165196 (19) 49.61 (41) 0
82Se 81.9166978 (23) 8.73 (22) 0

Isotopic abundances of Se
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 selenium are listed above. This table gives information about some radiosotopes of selenium, 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
70Se 69.9335 41.1 m EC to 70As 0
71Se 70.9319 4.7 m EC to 71As 5/2
72Se 71.92711 8.5 d EC to 72As 0
73Se 72.92678 7.1 h EC to 73As 9/2
75Se 74.922524 119.78 d EC to 75As 5/2 0.67
79Se 78.918500 65000 y β- to 79Br 0 -1.018
81Se 80.917993 18.5 m β- to 81Br 1/2
83Se 82.919119 22.3 m β- to 83Br 9/2
84Se 83.91847 3.3 m β- to 84Br 0

Sheffield ChemPuter isotope pattern calculator

You can use WebElements to calculate an isotope pattern for an arbitrary chemical formula:

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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. 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]
  3. For further information about radioisotopes see Jonghwa Chang's (Korea Atomic Energy Research Institute) Table of the Nuclides

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selenium atomic number