A sample of solid ammonium nitrate is stirred into water. The solid dissolves completely, the temperature of the solution drops by about 5∘C, and the liquid remains colorless and transparent. Which statement best classifies the overall process?
a) It is a chemical change because ionic compounds separate into ions when they dissolve.
b) It is a physical change because only dissolution occurs and no new substances form.
c) It is a chemical change because the temperature change demonstrates that energy is released or absorbed.
d) It is a physical change because the total mass of the beaker’s contents remains constant.