What does a higher activation energy imply about a reaction?

A higher activation energy indicates that a greater amount of energy is required for the reactant particles to collide with the appropriate orientation and sufficient energy to overcome the energy barrier associated with the reaction. This means that the likelihood of successful collisions occurring is reduced at lower temperatures because fewer particles possess the necessary energy to overcome this activation energy. As a result, reactions with higher activation energies tend to proceed more slowly unless enough energy is supplied to facilitate those successful collisions.

This understanding of activation energy is fundamental to the concept of reaction kinetics, which examines how various factors influence the rates of chemical reactions. In contrast to what other choices may imply, simply having a high activation energy does not directly denote spontaneity, catalytic effects, or the thermodynamic nature (exothermic or endothermic) of the reaction.