Cambridge IGCSE Chemistry · Syllabus 0620 · Chemical Reactions
Successful Collision
What is Successful Collision?
A collision between reacting particles in which the particles have a combined energy at least equal to the activation energy, so that bonds break and products form. The rate of a reaction is set by how many successful collisions occur per unit time, not by the total number of collisions.
This definition is part of the Chemical Reactions chapter in Cambridge IGCSE Chemistry.
Examiner tips on Successful Collision
- Marking yourself honestly. Award a mark only where your answer contains the idea in the marking point, not merely a related word. If you wrote “more collisions” where the point says “more successful collisions”, that is not a mark. These marking points are original to this chapter and are a guide to completeness, not a Cambridge mark scheme, so treat your score as a map of what to revise rather than as a prediction. Whatever the total, the useful step is the same: list the sections that produced the losses and return to those, rather than repeating the paper.