DEFININGCONSTANT: Boltzmann constant
- PID: si:definingconstant:boltzmann_constant:2019
- Definition: The Boltzmann constant, k, is exactly 1.380 649 × 10-23 J/K.
- Source: SI Brochure 9th Ed. 2019, p 127
1.380 649 x 10-23 J s
- Numerical Value: 1.380649E-23
- Unit: J K-1
- Unit in Base SI: kg m2 s-1 K-1
- This value was fixed by the CGPM in 2018 (Resolution 1), with effect from 20 May 2019.
- The Boltzmann constant is a proportionality constant between the quantities temperature (with unit kelvin) and energy (with unit joule).
- In statistical physics the Boltzmann constant connects the entropy S with the number Ω of quantum-mechanically accessible states: S = k ln Ω.
- Related Definitions
- hasConstantSymbol -> k