What is What is rate of reaction??

Rates & Collision Theory — GCSE Chemistry Revision

The basics

The Chemistry of Speed

📖 The Chemistry of Speed

Some reactions happen in an instant — an explosion, a firework, a neutralisation. Others take years — iron rusting, rocks weathering, wine maturing. But what makes one reaction lightning-fast while another crawls along? The answer lies in something beautifully simple: collisions. For a reaction to happen, particles must collide with enough energy AND in the right orientation. The rate of reaction depends on how often these "successful collisions" occur. Understanding this lets us control chemistry — speeding up industrial processes, slowing down food spoilage, and optimising everything from medicine to manufacturing.

🎱 The Pool Table Analogy

Reactions are like potting balls in pool! Particles must collide (balls must hit) with enough energy (hard enough) AND at the right angle (correct aim) for a successful pot. More balls on the table = more collisions = more chances to score. This is collision theory — successful reactions need enough energy AND the right orientation!

What is rate of reaction?: How quickly reactants are used up or products are formed

Key terms

Chemistry glossary

What is rate of reaction?: How quickly reactants are used up or products are formed

Spotlight

Deep Dive: Collision Theory

For a reaction to occur, particles must:

Exam tip

Earn the mark scheme marks

🧠 Memory Aid: CEO

To remember the conditions for a successful collision, think of the letters CEO:

C — COLLIDE (particles must physically meet)
E — ENERGY ≥ Ea (must exceed activation energy)
O — ORIENTATION (must hit at the right angle)

A CEO runs a company — all three must be present for the company (reaction) to succeed. If any one is missing, nothing happens!

Rates & Collision Theory