What type of reaction is described as exothermic?

An exothermic reaction is characterized by the release of energy in the form of heat to the surroundings. This typically occurs when chemical bonds are formed, leading to the production of heat and sometimes flames. In such reactions, the products have less energy than the reactants, resulting in excess energy being released, which can create observable heat and flames.

This explains why the response indicating a reaction that causes heat and flames is correct. In practical terms, common exothermic reactions include combustion, respiration, and many types of chemical reactions where new bonds are formed, releasing energy.

The other options involve scenarios that do not define exothermic reactions. For instance, a reaction that absorbs heat refers to endothermic processes, while a reaction that releases light may not necessarily involve heat release in significant amounts. Lastly, high-pressure reactions can occur in both exothermic and endothermic reactions, and thus do not define a characteristic of exothermic reactions specifically.