Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
An exothermic reaction is a chemical reaction that releases heat or energy to its surroundings during its progress. It usually feels warm or hot to touch.
Related terms
Endothermic Reaction: A chemical reaction that absorbs heat or energy from its surroundings, making the surroundings feel cooler.
Activation Energy: The minimum amount of energy required for a chemical reaction to occur.
Enthalpy: The total heat content of a system at constant pressure, including both internal energy and the work done by the system on its surroundings.