Boltzmann constant

For the constant pertaining to energy of black body radiation see Stefan–Boltzmann constant

Values of k	Units
1.380649×10^−23	J K^−1
8.617333262×10^−5	eV K^−1
1.380649×10^−16	erg K^−1

The Boltzmann constant (k or k_B) is a physical constant. It is defined to be 1.380649×10⁻²³ J/K.^[1] It relates the average kinetic energy of a particle in a gas with the temperature of the gas. It is the gas constant R divided by the Avogadro constant N_A:

${\displaystyle k={\frac {R}{N_{\rm {A}}}}\,}$

The Boltzmann constant has SI units of J⋅K⁻¹ (also written J/K), the same as entropy. It is named after the Austrian physicist Ludwig Boltzmann.

References

1. SI Brochure: The International System of Units (SI) (PDF) (Ninth ed.), Bureau International des Poids et Mesures, 2019, p. 129, retrieved 2020-01-18