Title: isotopic abundance
Long Title: IUPAC Gold Book - isotopic abundance
DOI: 10.1351/goldbook.I03332
Status: current

Definition
The relative number of atoms of a particular isotopes in a mixture of the isotopes of an element, expressed as a fraction of all the atoms of the element.

Related Term
- isotopes: https://goldbook.iupac.org//terms/view/I03331

Source
- PAC, 1982, 54, 1533. 'Glossary of terms used in nuclear analytical chemistry (Provisional)' on page 1535 (https://doi.org/10.1351/pac198254081533)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/I03332/html
- json: https://goldbook.iupac.org/terms/view/I03332/json
- xml: https://goldbook.iupac.org/terms/view/I03332/xml

Citation: Citation: 'isotopic abundance' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.I03332
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Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.
Accessed: 2026-07-31T19:26:01+00:00