This quantity equals the negative partial derivative of the grand potential with respect to temperature. Ignoring the indistinguishability of particles leads to a non-extensive form of this quantity in the Gibbs paradox. Like temperature, (10[1])the Carnot cycle contains two steps in which this quantity is constant. (-5[2])This quantity was defined as proportional to the natural logarithm of the number of microstates (10[2])by Ludwig (10[2])Boltzmann. (10[2])The “arrow (-5[1])of time” is defined because this quantity is (-5[1])non-decreasing for isolated systems by the Second Law of Thermodynamics. For 10 points, name this quantity that is informally the amount of disorder in a system. ■END■ (10[2])