1. The problem statement, all variables and given/known data A system has three energy levels, E1=0, E2 =1 and E3 = 2. In a certain state of the system, the probability that energy level 1 is occupied is 0.1, that energy level 2 is occupied is 0.8, and that energy level 3 is occupied is 0.1. Is this an equilibrium or a non-equilibrium state of the system? Explain why or why not. What is the average energy of the system in this state? 2. Relevant equations 3. The attempt at a solution So for the first part, I said that it was not in equilibrium because the system is at equilibrium when the disorder is at its greatest. The disorder is at its maximum when thermal energy is dispersed evenly within the 3 energy levels, and would therefore be equally probable in each three states. Since they are not equally probable, it is not in equilibrium. For the second part, I'm not sure if I'm doing it the right way. I put E = E1 + E2 + E3 because of their probability, we get E = 0.1E1 + 0.8E2 + 0.1E3, and given E = 3/2 KT we get 10E = 3/2KT1 + 8(3/2KT2) + 3/2KT3 10E = 3/2K(T1 + 8T2 + T3) E= 3/20K(T1 + 8T2 + T3) Avg energy = 1/3E = 1/20K(T1+8T2+T3) I'm not sure if I'm doing this right or they want it this way, help is appreciated.