Collision theory [Higher tier only]

A collision with too little energy will not produce a reaction.

Two pairs of particles move towards each other.

1. Two pairs of particles move towards each other

The colliding particles must have enough energy for the collision to be successful or effective in producing a reaction.

The minimum amount of energy for a collision to be successful is called the activation energy.

The rate of a reaction depends on the rate of successful collisions between reactant particles. The more successful collisions there are, the faster the rate of reaction.