1. The problem statement, all variables and given/known data For which process does the system absorb energy in the form of work? a) Water Evaporates into steam. b)Air is compressed by a bicycle pump. c) Both 2. Relevant equations 3. The attempt at a solution I though the answer was both. However, the key says the correct answer was just B. Why would it not be A as well? I thought evaporation required the input of energy.