The Energy-Interaction Model tells us what is energy, how it is conserved, and how it is transferred. We will see that by applying the Energy-Interaction Model to seemingly very strange thermal phenom...The Energy-Interaction Model tells us what is energy, how it is conserved, and how it is transferred. We will see that by applying the Energy-Interaction Model to seemingly very strange thermal phenomena, we can make sense of them, we can explain what is going on, and we can answer all kinds of questions about the phenomena. In this Chapter we will apply Energy-Interaction Model to substances going through temperature changes or phase changes and to several chemical reactions.