Boltzmann constant

symbol: $k$
https://doi.org/10.1351/goldbook.B00695
The Boltzmann constant, \(k\), is one of seven fixed constants defining the International System of Units, the SI, with \(k = \pu{1.380649E-23 J K-1}\). The Boltzmann constant is a proportionality constant between the quantities temperature (with unit kelvin) and energy (with unit joule).
Sources:
BIPM, The International System of Units, SI Brochure, 9th ed. (2019), p. 127 [Terms] [Book]
Newell et al., Metrologia 55, L13-L16 (2018) [Terms] [Source]
Citation: 'Boltzmann constant' 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.B00695 RIS BibTex EndNote
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