Question

which is the best definition of activation energy?
the energy required to end a chemical reaction
the energy required to bind a substrate to an active site
the energy required to form or break the bonds of reactant molecules
the energy required to re - form bonds in product molecules

Explanation:

Activation energy is the energy needed to start a reaction by breaking or forming reactant - molecule bonds.

Answer:

the energy required to form or break the bonds of reactant molecules