What happens as the activation energy increases?
the pressure of the system decreases.
the kinetic energy of colliding molecules changes.
the reactant surface area decreases.
the reaction begins to slow down.

the kinetic energy of the colliding molecules changes

Option (d) is the correct answer.

Explanation:

Activation energy is the minimum energy required by the reactants to undergo a specified reaction.

When there is increase in activation energy then energy barrier will also increase therefore, reactant molecules will less energy cannot cross the energy barrier.

As a result, they will not participate in the reaction and hence, there will be decrease in rate of reaction.

Thus, we can conclude that the reaction begins to slow down as the activation energy increases.

explanation: