A complete guide to Cambridge IGCSE Chemistry

Cambridge IGCSE Chemistry (specification 0620) is the international equivalent of GCSE Chemistry, run by Cambridge Assessment International Education (CAIE). It is sat by students at international schools worldwide and by a number of UK independent schools that prefer a fully linear, exam-only science qualification. The course is structured around twelve topic areas and is assessed across three papers.

This guide walks through everything you need to know to sit the exam with confidence: How the papers are structured, the difference between Core and Extended, how the practical assessment works, and the revision techniques that work best for IGCSE chemistry.

Cambridge IGCSE Chemistry is a fully linear qualification. Everything you learn is assessed at the end of the course, usually in May/June or October/November. There is no controlled assessment and no coursework component to worry about.

The qualification is tiered into two routes. The Core route uses easier papers and gives access to grades C to G. The Extended route covers all of Core plus additional Extended-only content and unlocks grades A* to E. Your school decides which route to enter you for based on your performance during the course.

Cambridge IGCSE Chemistry is structured around twelve topics that span the breadth of school-level chemistry, from the particulate nature of matter through to industrial chemistry and organic synthesis.

1. The particulate nature of matter (states, kinetic theory, diffusion)
2. Experimental techniques (separation methods, purity, chromatography)
3. Atoms, elements, and compounds (atomic structure, isotopes, bonding, ions)
4. Stoichiometry (formulae, equations, the mole, calculations from equations)

1. Electricity and chemistry (electrolysis of molten and aqueous compounds)
2. Chemical energetics (exothermic and endothermic reactions, energy profile diagrams)
3. Chemical reactions (rates of reaction, reversible reactions, redox, equilibrium)
4. Acids, bases, and salts (pH, neutralisation, preparation of salts)

1. The periodic table (group I, group VII, transition elements, noble gases)
2. Metals (reactivity series, extraction of metals, alloys)
3. Air and water (composition, pollution, water treatment, fertilisers)
4. Organic chemistry (alkanes, alkenes, alcohols, carboxylic acids, polymers)

Cambridge IGCSE Chemistry has a 20% practical component. Schools can choose between two options for assessing this: Paper 5 (a physical practical test) or Paper 6 (a written alternative to practical paper).

A 1 hour 15 minute practical exam sat in a lab. You will be given a set of materials and asked to carry out an investigation, record observations, plot graphs, and answer questions on method and error. It is marked out of 40.

A 1 hour written paper that tests the same practical skills as Paper 5 without any physical lab work. You answer questions on apparatus, methods, variables, observations, and graph drawing using data provided in the paper.

Most international schools enter their candidates for Paper 6 because it removes the logistical complexity of running a timed lab exam. Both options assess the same skills and are worth the same weighting in the final grade.

Cambridge IGCSE Chemistry is graded A* to G (with U for ungraded). The Core route gives access to grades C to G. The Extended route gives access to grades A* to E. There is overlap in the middle, so a strong Core candidate can earn a C and a weaker Extended candidate can also earn an E or D.

Most academically able students take Extended because it unlocks the higher grades and is the route accepted as equivalent for top universities. Your school will normally make the final call based on mocks and class performance. Grade boundaries shift every series and are set separately for May/June and October/November.

Cambridge publishes the official boundaries on results day each August and January.

IGCSE Chemistry rewards precision. The students who get A* train themselves to use exact chemical language, write balanced symbol equations on demand, and spot the patterns in question types. Volume of practice matters, but the right kind of practice matters more.

Stoichiometry is the thread that runs through half the Extended paper. If you cannot rearrange n = m / Mr fluently, you will lose marks on every quantitative question. Drill mole maps daily for the first two weeks of revision until the calculation is automatic, then keep them in your weekly rotation.

Tests for cations, anions, and gases appear in nearly every Paper 5 and Paper 6. Make a single sheet with every test, the reagent, the observation, and the chemistry behind it. Quiz yourself on it weekly until you can recall any test on demand.

Bonding questions are nearly free marks if your diagrams are tidy. Practise ionic, covalent, and giant covalent structures until you can draw them in under thirty seconds. Show the electrons clearly, label the charges on ions, and use brackets where required.

The reactivity series underpins displacement, extraction, and electrolysis questions. Memorise it from potassium down to gold and learn the typical reactions of each metal with water, oxygen, and acids. This is one of the highest-yield pieces of recall in the whole spec.

Doing a past paper and putting it back on the shelf is wasted work. Mark it honestly, write down every topic where you dropped marks, and revise that specific content before doing another paper. The biggest jumps in IGCSE scores come from fixing recurring weaknesses, not from churning more papers.