Term: Planck constant, \(h\)
https://doi.org/10.1351/goldbook.P04685

Definition:
The Planck constant, \(h\), is one of seven fixed constants defining the International System of Units, the SI, with h = 6.626 070 15 × 10-34 J s. The Planck constant is considered as a fundamental constant of nature.

Source: BIPM, The International System of Units, SI Brochure, 9th ed. (2019), p. 127ff (https://www.bipm.org/en/publications/si-brochure/)

Citation: 'Planck constant, \(h\)' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.P04685

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