Activation energy of a reaction: is an alternative term for the free energy of activation. is decreased in the presence of an enzyme specific for that reaction. is the amount of free energy required to bring the reactants to the transition state. determines if the reaction is spontaneous.

Activation energy, in chemistry, is the minimum amount of energy that is required to activate atoms or molecules to a condition in which they can undergo chemical transformation or physical transport. Basically, activation energy is that push that atoms need in order to undergo reactions.

All chemical reactions, including exothermic reactions, need activation energy to get started. Activation energy is needed so reactants can move together, overcome forces of repulsion, and start breaking bonds.

A catalyst lowers the activation energy of a reaction, so that a chemical reaction can take place. Increasing the temperature of a reaction has the effect of increasing the number of reactant particles that have more energy than the activation energy. Enzymes are a form of catalysts that speed up chemical reactions by lowering the activation energy.

The correct options are therefore;

- is decreased in the presence of an enzyme specific for that reaction.

- is the amount of free energy required to bring the reactants to the transition state.

- is an alternative term for the free energy of activation.