In a computer model of a reaction, the temperature setting is increased while everything else stays the same. The model shows that the particles collide more often and that a larger proportion of the collisions are successful.
Which statement explains both of these effects?
The particles expand, so they are more likely to hit each other
More particles are packed into each unit of volume of the mixture
The particles move faster, so they have more kinetic energy
The activation energy falls, so less energy is needed to react
127 exam-style questions on AQA GCSE Chemistry 6.1 Rate of reaction, covering 6.1.1a Calculating rates of reactions, 6.1.1b Gradient of a tangent as rate, 6.1.2 Factors which affect the rates of chemical reactions, 6.1.3 Collision theory and activation energy, and 6.1.4 Catalysts. Each one has a worked solution and a mark scheme showing where the marks go.