Title: nuclide
Long Title: IUPAC Gold Book - nuclide
DOI: 10.1351/goldbook.N04257
Status: current

Definition
A species of atom, characterized by its mass number, atomic number and nuclear energy state, provided that the mean lifetime in that state is long enough to be observable.

Related Terms
- atomic number: https://goldbook.iupac.org//terms/view/A00499
- mass number: https://goldbook.iupac.org//terms/view/M03726
- mean lifetime: https://goldbook.iupac.org//terms/view/M03780

Sources
- Orange Book, 2nd ed., p. 233 (https://media.iupac.org/publications/analytical_compendium/)
- PAC, 1982, 54, 1533. 'Glossary of terms used in nuclear analytical chemistry (Provisional)' on page 1547 (https://doi.org/10.1351/pac198254081533)
- PAC, 1994, 66, 2513. 'Nomenclature for radioanalytical chemistry (IUPAC Recommendations 1994)' on page 2522 (https://doi.org/10.1351/pac199466122513)
- Red Book, 3rd ed., p. 35

Other Outputs
- html: https://goldbook.iupac.org/terms/view/N04257/html
- json: https://goldbook.iupac.org/terms/view/N04257/json
- xml: https://goldbook.iupac.org/terms/view/N04257/xml

Citation: Citation: 'nuclide' 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.N04257
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Accessed: 2026-05-18T04:52:30+00:00