Science Constants - Boltzmann Constant Symbol: k Value: 1.3806503(24) × 10-23 J K-1 8.617342(15) × 10-5 eV K-1 2.0836644(36) × 1010 Hz K-1 Category: - Physico-Chemical Constants Description: The Boltzmann Constants relates the average kinetic energy of a molecule in an ideal gas to its absolute temperature.   The value was defined by the 19th century Austrian physicist, Ludwig Boltmann