This quantity equals the negative partial derivative of the grand potential with respect to temperature. Ignoring the indistinguishability of particles leads to a (10[1])non-extensive (10[2])form of this quantity (10[1])in the Gibbs paradox. Like (10[1])temperature, (10[1])the Carnot cycle (10[1])contains two steps (10[1])in which this (10[1])quantity (10[1]-5[1])is constant. (10[3]-5[8])This quantity (10[1])was defined as proportional to the (-5[1])natural (10[1])logarithm of the number (10[1])of microstates (10[6])by (10[1])Ludwig (10[5])Boltzmann. (10[9]-5[1])The (10[1])“arrow (10[1]-5[1])of time” is defined (10[2])because this quantity (10[2])is (10[1]-5[1])non-decreasing (10[1])for isolated (10[2])systems (10[2])by (10[1])the Second Law of Thermodynamics. (10[2])For 10 (10[2])points, (10[1])name this quantity that is informally the amount of (10[1])disorder in a system. (10[1]0[1])■END■ (10[5]0[1])