An exothermic reaction is a chemical reaction that releases heat energy to the surroundings. It is characterized by a negative change in enthalpy (∆H) and often results in an increase in temperature.
Activation energy is the minimum amount of energy required for a chemical reaction to occur. It acts as a barrier that must be overcome before reactants can form products.
Enthalpy (∆H): Enthalpy is a measure of heat content within a system during chemical reactions. A negative ∆H indicates an exothermic reaction since it releases heat energy.