Given the task definition and input, reply with output. In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

One form of this quantity is equal to h-bar squared divided by two times Boltzmann's constant times the molecule's moment of inertiathat form simplifies the expression for the rotational partition function. It's not the number of particles, but this quantity is a natural variable for both the Gibbs and Helmholtz free energies. This quantity is located in the denominator of the integrand in the (*) Clausius inequality. This quantity is the thermodynamic conjugate of entropy. Equipartition states the kinetic energy of a monatomic ideal gas is 3/2 times Boltzmann's constant times this quantity. Gibbs free energy is equal to enthalpy minus entropy times this quantity. For 10 points, name this quantity found in the denominator of the combined gas law, which is often measured in Kelvin.
Science