What occurs during an exothermic reaction?

During an exothermic reaction, the system releases energy to its surroundings. This means that the reactants have higher energy than the products, and the excess energy is typically given off as heat. This is why exothermic reactions often feel warm to the touch; the thermal energy generated warms the surrounding environment.

In terms of thermodynamics, the enthalpy (ΔH) of the reaction is negative, indicating that energy is being released. This release of energy can also drive the progress of the reaction forward, as it can lead to the formation of products that are more stable and lower in energy compared to the reactants.

This is a fundamental behavior in chemical thermodynamics and is crucial for understanding various chemical processes, including combustion reactions, respiration, and many polymerization processes.