Successful collision

A collision below this threshold does not produce a reaction; one with enough energy can be a successful collision. The reaction is faster when successful collisions happen more frequently — that is, when there are more of them each second.

A collision that does produce a reaction is called a successful collision.

If more successful collisions happen each second, the rate of reaction is greater. This is why the same mass of calcium carbonate powder reacts with hydrochloric acid faster than calcium carbonate granules or chips.

A collision that has sufficient energy and a suitable orientation is called a successful collision. During it, the reactants briefly pass through a very unstable, high-energy arrangement before product bonds form. This temporary arrangement is sometimes called the activated complex.