The figure shows a cube of air at pressure 1.0 atm above a hot surface on Earth. Contact with the hot surface causes the volume of the air to expand from 2.00 × 105 L to 2.20 × 105 L by the transfer of 8.2 × 106 J of heat. Assume the systems are isolated from the outside world but not from each other. a. Identify the two systems involved in this process. (1 point)

b. Determine the change in energy for the air. Show your calculations. (Use the conversion 1 L· atm = 101.3 J.) (3 points)

c. What is the direction of energy flow between the systems? (1 point)