Contents

States of matter

Atoms, elements and compounds

Stoichiometry

Electrochemistry

ElectrolysisBeing prepared
Electrolysis of solutions and electroplatingBeing prepared
Fuel cellsBeing prepared

Chemical energetics

Chemical reactions

Acids, bases and salts

Acids, bases and indicators
OxidesBeing prepared
Making saltsBeing prepared

The Periodic Table

Reading the tableBeing prepared
Group I: the alkali metalsBeing prepared
Group VII: the halogensBeing prepared
Transition elements and noble gasesBeing prepared

Metals

Metals and alloysBeing prepared
The reactivity seriesBeing prepared
CorrosionBeing prepared
Extracting metalsBeing prepared

Chemistry of the environment

WaterBeing prepared
FertilisersBeing prepared
Air quality and climateBeing prepared

Organic chemistry

Naming organic moleculesBeing prepared
Crude oil and alkanesBeing prepared
AlkenesBeing prepared
Alcohols and carboxylic acidsBeing prepared
PolymersBeing prepared

Experimental techniques and chemical analysis

Mixtures and separation
Measuring and planning experimentsBeing prepared
Crystallisation
Distillation
Paper chromatography
Choosing methods and checking purityBeing prepared
TitrationBeing prepared
Gas testsBeing prepared
Anion testsBeing prepared
Cation and flame testsBeing prepared

Part 3 of 3

Page 03

Why collisions matter

identify

Try it yourself

Supplement. What must happen for two particles to react?

identify: name or select.

Choose one answera.They must collide head-on, whatever their energyb.They must collide with a particle of a catalystc.They must collide with at least the activation energyd.They must collide with at least the energy of the products

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Scope and sources

Cambridge IGCSE Chemistry 0620 · 2026–2028 v2 · Original learning materials.

Rate of reaction (6.2 Core 1–4, Supplement 5–8): the effect of concentration, gas pressure, surface area, temperature and a catalyst, catalysts and enzymes, practical methods for following a rate and interpreting its data, collision theory and activation energy. Moles and gas volumes are in an earlier module; reversible reactions and equilibrium in 6.3.

Apparatus, amounts and times in the experiment are illustrative. Real practical work follows a teacher-approved safety method.

Official Cambridge syllabus