A catalyst works by

lowering the activation energy barrier

changing the particle size of the reactants

changing the temperature of the reactants

shifting the equilibrium position toward the products

A catalyst works by lowering the activation energy barrier.

By lowering the activation energy requirement, the chemical reaction will require less energy to complete.

-T. B.

The answer is lowering the activation energy barrier.

Explanation:

The speed of a chemical reaction is the speed at which the reaction continues towards equilibrium. In a catalyzed reaction, velocity is expressed as the amount of a product that is produced per minute. Said reaction rate is governed by the energy barrier between the reagents and the products. In general terms, that energy must be added to the reagents to pass the energy barrier. This added energy is known as the activation energy, for example, enzymes have the ability to accelerate the speed of a reaction. Enzymes are known as biological catalysts. These catalysts accelerate the speed of reactions by lowering the activation energy barrier between reagents and products in a reaction.