Energy refers to the capacity of a system to do work or produce heat. In chemical reactions, energy can be released (exothermic) or absorbed (endothermic).
Related terms
Activation Energy: The minimum amount of energy required for molecules to undergo a chemical reaction.
Enthalpy Change (∆H): The difference in heat content between reactants and products in a chemical reaction.
Calorimetry: A technique used to measure heat changes during chemical reactions.