activation energy
Sign in to saveenergy that must be input to a system to undergo a reaction or process
AI overview
Activation energy is the amount of energy that needs to be added to a system before a chemical reaction or process can begin. It matters because even reactions that would ultimately release energy often require this initial energy boost to get started, which is why a match needs a spark to ignite wood, for example.
AI-generated from the Wikipedia summary — may contain errors.
Article
The sparks created by striking steel against a piece of flint provide the activation energy to initiate combustion in this Bunsen burner. The blue flame sustains itself after the sparks stop because the continued combustion of the flame is now energetically favorable.
In the Arrhenius model of reaction rates, activation energy is the minimum amount of energy that must be available to reactants for a chemical reaction to occur. The activation energy (Ea) of a reaction is measured in kilojoules per mole (kJ/mol) or kilocalories per mole (kcal/mol). Simplified: