If a chemical reaction causes the surroundings to become warmer, is the reaction exothermic or endothermic? Why?

• A. Endothermic, because energy is absorbed from the surroundings.
• B. Endothermic, because the surroundings heat up.
• C. Exothermic, because energy is released to the surroundings.
• D. Exothermic, because energy is released to the environment.

Answer: (C)