- Boltzmann constant
the ratio of the universal gas constant to Avogadro's number, equal to 1.3803 × 10-16 erg per degree C. Symbol: kAlso, Boltzmann's constant.[1905-10; after L. BOLTZMANN]
* * *Ratio of the universal gas constant (see gas laws) to Avogadro's number.It has a value of 1.380662 × 10-23 joules per kelvin. Named after Ludwig Boltzmann, it is a fundamental constant of physics, occurring in nearly every statistical formulation of both classical and quantum physics.
* * *▪ physics(symbol k), a fundamental constant of physics occurring in nearly every statistical formulation of both classical and quantum physics. The constant is named after Ludwig Boltzmann (Boltzmann, Ludwig Eduard), a 19th-century Austrian physicist, who substantially contributed to the foundation and development of statistical mechanics, a branch of theoretical physics. Having dimensions of energy per degree of temperature, the Boltzmann constant has a value of 1.380650 × 10−23 joule per kelvin (K), or 1.380650 × 10−16 erg per kelvin.The physical significance of k is that it provides a measure of the amount of energy (i.e., heat) corresponding to the random thermal motions of the molecules of a substance. For a classical system at equilibrium at temperature T, the average energy per degree of freedom is kT/2. In the simplest example of a gas consisting of N noninteracting atoms, each atom has three translational degrees of freedom (it can move in the x-, y-, or z-directions), and so the total thermal energy of the gas is 3NkT/2.
* * *