Collision Theory

Contents

Key Stage 4

Meaning

Collision Theory is a scientific theory which explains that reactions take place via the collision of particles of reactants.

About Collision Theory

Collision Theory is based on the Kinetic Theory which explains the motion of particles in matter.

In Collision Theory particles are said to collide with one another and that if two reactants in a reaction collide with enough energy this will cause them to react.

Temperature and Collision Theory

Kinetic Theory explains how increasing the temperature of a substance causes the particles to gain more kinetic energy so they travel faster. When particles travel faster (due to higher temperatures) they collide with more energy and they collide more frequently (more often). This means at higher temperatures particles of the reactants are more likely to collide with each other and they are more likely to have enough energy to react when they do. This increases the rate of reaction.

Pressure and Collision Theory

The Particle Model explains how increasing the pressure on a gas, and compressing it, causes the particles in that gas to collide more frequently (more often). This means at higher pressures the particles of reactants will collide more often, increasing the chances of them reacting.