IEVref: 113-02-17 ID: Language: en Status: Standard Term: Boltzmann constant Synonym1: Synonym2: Synonym3: Symbol: kkB Definition: conventional physical constant which relates the thermodynamic temperature and energy, the value of which is set to 1,380 649 × 10−23 J/K Note 1 to entry: The Boltzmann constant relates the average kinetic energy E of particles in an ideal gas to the thermodynamic temperature T of the gas as follows: $E=\frac{3}{2}kT$. Note 2 to entry: The Boltzmann constant is used in the SI to define the kelvin. Publication date: 2020-12 Source: SI Brochure, 9th edition, 2019, 2.2, modified – The definition in the SI Brochure has been revised to comply with the IEV rules. Replaces: Internal notes: CO remarks: TC/SC remarks: VT remarks: Domain1: Domain2: Domain3: Domain4: Domain5: