Title: X-ray level
Long Title: IUPAC Gold Book - X-ray level
DOI: 10.1351/goldbook.X06715
Status: current

Definition
An electronic state occuring as the initial or final state of a process involving the absorption or emission of X-ray radiation. It represents a many-electron state which, in the purely atomic case, has total angular momentum (\(J = L + S\)) as a well defined quantum number.

Related Terms
- angular momentum: https://goldbook.iupac.org//terms/view/A00353
- electronic state: https://goldbook.iupac.org//terms/view/ET07026

Source
- PAC, 1991, 63, 735. 'Nomenclature, symbols, units and their usage in spectrochemical analysis - VIII. Nomenclature system for X-ray spectroscopy (Recommendations 1991)' on page 737 (https://doi.org/10.1351/pac199163050735)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/X06715/html
- json: https://goldbook.iupac.org/terms/view/X06715/json
- xml: https://goldbook.iupac.org/terms/view/X06715/xml

Citation: Citation: 'X-ray level' 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.X06715
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Accessed: 2026-01-12T23:47:19+00:00