Collision Model vs Activated Complex Model

[jessicaosuna_1F]

Hi! Can somebody please explain the difference between these 2 models. Thank you :)

[Andreas Krumbein 1L]

An activated complex consists of two molecules that are in a "transition state" meaning they can continue to form a new molecule or they can break apart again. Whether they form a new product or not depends on the amount of energy accumulated from their collision (if it's at least equal to Ea). Collision theory is similar in that the minimum kinetic energy required for a reaction to occur is equal to Ea.

[Katherine_Douglas_1F]

These are two different ways of looking at how activation energy is determined. In the collision model, activation energy is related to the amount of energy that needs to be transferred within a collision in order for the reaction to occur. Activated complex model instead compares an intermediate (the activated complex) to the reactants and the activation energy is the difference between the two.