Endothermic: An endothermic reaction is the opposite of exothermic. It absorbs heat energy from the surroundings, resulting in a decrease in temperature.
Activation Energy: 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.