Activation energy

Definition

Activation energy is the energy barrier that molecules must clear before a reaction can proceed.

Raising temperature gives more molecules enough energy to clear the barrier, which speeds the reaction. The first step of oxygen reduction carries an activation energy barrier, which is part of why oxygen reacts slowly. It is the underlying reason temperature controls reaction rate.

Related concepts

Arrhenius rule of thumb · Kinetic restraint of oxygen · Reaction kinetics

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Part of The Blueprint of Water · 🔥 thermodynamics