Microstates and Macrostates Two common ways of stating the Second Law of Thermodynamics are: heat always moves from hot to cold, and heat engines are always less then 100% efcient. In this activity we will examine another, equivalent, way of stating the Second Law: The total entropy of an isolated system can increase, but it cannot decrease. In 1877 Ludwig Boltzmann showed that entropy can he understood in terms of the motion of the molecules that compose a physical system. To understand Boltzmann's ideas we must first. understand what is meant by entropy, and to understand entropy we must first discuss m'icmsaies and macrostates. A microstate is a state of a physical system described at the nest level of detail. A macrostate is a state of a physical system that is described in terms of the systems overall or average properties at a macroscopic level. A macrostate will generally consist of many different microstates. In dening a macrostate we ignore what is going on at the microscopic (atomic/ molecular) level. 2. Now suppose you had a class roster showing the names of all 24 students enrolled in this class. If I specified the macrostate of the class by saying that there are 24 students present, could you tell me what the microstate is? Why or why not? 3. If I specified the macrostate of the class by saying that there are 15 students present, could you tell me what the microstate is? Why or why not?4. This example illustrates the fact that some macrostates provide a great deal of information about the microstate of the system. This is the case when the macrostate contains only one= or a small number, of microstates. A system in one of these maerostates is said to have a low entropy. Other macrostates tell 11s very little about the microstate of the system. This is the case when the Inaxtrostate contains a. large number of different microstates. A system in one of these niacrostates is said to have a high entropy. Which of the following lnaerostates of the class would have the highest entropy? (a) All 2/1 students are present. (1)) 12 students are present. (a) 1 student. is present. ((1) No students are present. 5. Which of the above choices would have the lowest entropy