Which term refers to a chemical reaction that releases heat energy?

• A. Endothermic reaction
• B. Exothermic reaction
• C. Neutralization
• D. Catalysis

Answer: (B)

The concept here is how heat flows in chemical reactions. When a reaction releases heat to its surroundings, it is exothermic. In an exothermic reaction the reactants start with more energy than the products, and the excess energy is given off as heat, often making the surroundings warmer. This contrasts with endothermic reactions, which absorb heat from the surroundings and feel cooler. Neutralization is a specific type of reaction that can release heat, but the general term for a reaction that releases heat is exothermic. Catalysis changes the rate of a reaction without inherently describing heat release or gain.