All substances have some degree of disorder because the particles are always in constant motion. The third law of thermodynamics states that the entropy at absolute zero (0K) is zero. As the substance is heated, it becomes more disordered, and there are large increases in entropy when the substance changes state.The values for the standard entropies given in data booklets are for a stated temperature - usually 298K. Standard entropies are given for standard conditions of 298K and 100kPa.