1. Fill in the best answer for each of the following: a) is the capacity to do work or to supply heat. b) is energy stored within a substance due to its chemical composition. c) A reaction that absorbs energy is called a(n) reaction. d) The says that in any chemical or physical change, energy can neither be created nor destroyed, only changed in form. e) Thermochemistry is the study of that occur during chemical and physical changes.