Free energy is a measure of the energy available to do work in a chemical reaction. It takes into account both the enthalpy (heat) and entropy (disorder) of the system.
Related terms
Activation Energy: The minimum amount of energy required for a reaction to occur. It acts as a barrier that must be overcome before the reaction can proceed.
Exergonic Reaction: A reaction that releases free energy, usually in the form of heat. These reactions tend to occur spontaneously.
Endergonic Reaction: A reaction that requires an input of free energy in order to proceed. These reactions are non-spontaneous and typically absorb heat from their surroundings.