Which of the following best describes an exothermic reaction?

An exothermic reaction is characterized by the release of energy, usually in the form of heat, resulting in the products having a lower energy state than the reactants. This means that energy has been lost from the system during the reaction, which is why the reactants possess more energy than the products.

In such reactions, the energy difference is often measured when the reaction occurs, and this energy loss often causes a temperature increase in the surroundings. This understanding aligns with the nature of exothermic processes, making it clear why the correct description is that the reactants have more energy than the products.

Other descriptions, such as the reactants having lower energy than products, imply that energy is gained instead of released, which does not represent an exothermic process. Similarly, the idea that heat is absorbed would describe an endothermic reaction, and stating that products have higher energy than reactants fails to capture the fundamental energy transfer that occurs in exothermic reactions.