IGCSE Chemistry (0620): The Complete Guide for Parents and Students
Based on the official Cambridge syllabus for 2026–2028 · Last reviewed July 2026
From atomic structure to organic chemistry, this guide covers every topic on the IGCSE Chemistry syllabus along with the command words and exam tips that matter most.
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Cambridge IGCSE Chemistry (0620) is one of the most widely taken science qualifications in international education, and for students in Malaysia it is often a key subject on the path to A-Level, IB and university, particularly for anyone considering medicine, engineering, pharmacy or the pure sciences. This guide explains everything a parent or student needs to know: what the course covers, the complete list of topics, how the three exam papers work (including the practical), the command words that decide marks, and how the qualification is graded.
Quick answer
IGCSE Chemistry (0620) is a tiered qualification: Core (grades C–G) or Extended (grades A*–G). Students sit three papers, multiple choice, theory, and a practical paper, and the practical counts for 20% of the grade. The course has twelve topics. A Periodic Table is provided, and calculators are allowed throughout.
Overview
What is IGCSE Chemistry (0620)?
Cambridge IGCSE Chemistry (syllabus code 0620) is the standard international chemistry qualification for students aged roughly 14 to 16, usually studied over Years 10 and 11. It builds a thorough knowledge of chemical ideas and develops the practical, data-handling and problem-solving skills that underpin all scientific study.
Tiered
Students follow either Core (grades C–G) or Extended (grades A*–G). Extended includes everything in Core plus a substantial body of additional Supplement material.
Practical requirement
Experimental skills are formally assessed and count for 20% of the final grade.
Study time
Approximately 130 guided learning hours, typically over Years 10 and 11.
Recognition
Internationally recognised, benchmarked as comparable to the UK GCSE, accepted by universities worldwide, and recognised by Malaysia’s Ministry of Education. Students achieving A* to C are well prepared for A-Level, IB and other science pathways.
Exam series
Available in the June and November series (and March in some regions).
Restrictions
Cannot be taken in the same series as Cambridge IGCSE (9–1) Chemistry (0971), IGCSE Physical Science (0652), IGCSE Combined Science (0653), the Co-ordinated Sciences double awards (0654 and 0973), O Level Chemistry (5070) or O Level Combined Science (5129).
New to IGCSE grading?
Our companion guide, The IGCSE Grading System Explained, covers A*–G, grade thresholds and what each grade means for your child’s next step.
What the course builds
Assessment objectives: where the marks actually come from
Every exam question tests one of three assessment objectives (AOs). Their weightings are fixed across the whole qualification and tell you exactly where the marks are:
50%
AO1, Knowledge
Recalling and understanding scientific facts, definitions, concepts, vocabulary, apparatus and applications. Tested in all papers.
30%
AO2, Problem-solving
Selecting and organising information, translating between forms, spotting patterns, drawing conclusions and solving problems, often in unfamiliar contexts.
20%
AO3, Practical skills
Planning experiments, using apparatus safely, recording observations and data, interpreting results, and evaluating methods. Tested entirely by the practical paper.
The theory and multiple-choice papers test AO1 and AO2 only (split roughly 63% AO1 to 37% AO2). The practical paper tests AO3 in full. This is a meaningful difference from a subject like Maths: a fifth of the whole Chemistry grade comes from experimental skills, so practical understanding matters just as much as theory.
The Most Important Decision
Core or Extended? Choosing the right tier
This is one of the most consequential decisions a family makes, because it sets a ceiling on the possible grade.
Core tier
Essential content
CDEFG
Grades C to G only. A Core candidate cannot be awarded above a C. Papers: 1 (MC) + 3 (theory) + practical.
Best for: students confident in essentials, not planning A-Level or IB Chemistry.
Extended tier
Core + Supplement content
A*ABCDEFG
Grades A* to G. Papers: 2 (MC) + 4 (theory) + practical.
Best for: anyone targeting top grades or planning A-Level / IB Chemistry.
The Supplement is not just “harder questions”, it introduces whole ideas the Core leaves out: the mole concept, ionic half-equations, collision theory, the Haber and Contact processes, condensation polymers, and more. Students targeting a grade C or above, and those planning any science-heavy pathway, should follow the Extended tier. A short diagnostic is the most reliable way to decide.
Studying more than one science?
Many Brainiac students take Chemistry alongside IGCSE Physics (0625). Our programmes share the same exam-technique approach so students build consistent habits across subjects.
The Exams
Exam format
All candidates take three papers: a multiple-choice paper, a theory paper, and one practical paper. The tier determines which multiple-choice and theory papers a student sits.
Paper
Type
Duration
Marks
Weight
Paper 1 (Core)
Multiple Choice
45 min
40
30%
Paper 2 (Extended)
Multiple Choice
45 min
40
30%
Paper 3 (Core)
Theory, short answer & structured
1 h 15 min
80
50%
Paper 4 (Extended)
Theory, short answer & structured
1 h 15 min
80
50%
Paper 5 (all)
Practical Test
1 h 15 min
40
20%
Paper 6 (all)
Alternative to Practical
1 h
40
20%
Core candidates sit Papers 1 + 3 + (5 or 6). Extended candidates sit Papers 2 + 4 + (5 or 6). Every candidate sits one practical paper, either Paper 5 or Paper 6, not both. Calculators are allowed in all parts of the examination.
What the practical paper actually assesses
Whether a student sits Paper 5 (lab) or Paper 6 (written), the practical tests the same skills drawn from experimental contexts such as: rates of reaction, salt preparation, separation and purification (filtration, crystallisation, distillation, chromatography), electrolysis, identifying ions and gases, titrations, heating and cooling curves, and displacement reactions. Candidates may need to identify apparatus, describe hazards, plan investigations, record measurements, plot graphs, draw conclusions and evaluate methods.
What is provided in the exam
Resources provided
A Periodic Table is provided in all papers. The practical papers (Papers 5 and 6) include “Notes for use in qualitative analysis”, the standard tables of ion tests, gas tests and flame tests. Students are not expected to memorise every colour and precipitate, but they must know how to use these tables confidently and fluently.
The Syllabus
The complete list of topics
Cambridge IGCSE Chemistry is organised into twelve topics. All candidates study all twelve; Extended students go deeper within each by adding the Supplement content. Click any topic to see the full content.
All students cover
Distinguishing properties of solids, liquids and gases; their structures in terms of particle separation, arrangement and motion
Changes of state: melting, boiling, evaporating, freezing and condensing
Effects of temperature and pressure on the volume of a gas
Diffusion explained using kinetic particle theory
Extended students also cover Extended
Explaining changes of state using kinetic particle theory; interpreting heating and cooling curves
Explaining the effects of temperature and pressure on gas volume quantitatively
Effect of relative molecular mass on the rate of diffusion of gases
All students cover
Elements, compounds and mixtures and the differences between them
Atomic structure: nucleus of protons and neutrons, electron shells; relative charges and masses; proton number and mass number; electronic configurations for elements 1–20
Isotopes: definition and how to interpret atomic and ionic symbols
Ionic bonding: formation of cations and anions, dot-and-cross diagrams for Group I / Group VII compounds, properties of ionic compounds
Covalent bonding: dot-and-cross diagrams for H₂, Cl₂, H₂O, CH₄, NH₃, HCl; properties of simple molecular compounds
Giant covalent structures: graphite and diamond; structure and uses
Extended students also cover Extended
Calculating relative atomic mass from isotopic abundances; why isotopes share chemical properties
Giant lattice structure of ionic compounds and explaining their properties
Covalent bonding in CH₃OH, C₂H₂, O₂, CO₂, N₂; weak intermolecular forces and properties
Giant covalent structure of silicon(IV) oxide
Metallic bonding: sea of delocalised electrons; explaining conductivity, malleability and ductility
All students cover
Stating and deducing chemical formulae; constructing word and symbol equations with state symbols
Relative atomic mass (Aᵣ) and relative molecular / formula mass (Mᵣ)
Calculating reacting masses in simple proportions (without the mole)
Concentration measured in g/dm³ or mol/dm³
Extended students also cover Extended
Empirical formulae; ionic equations
The mole and the Avogadro constant; the mole relationship (mass, molar mass, amount, number of particles)
Molar gas volume (24 dm³ at r.t.p.)
Stoichiometric reacting masses, limiting reactants, gas volumes, solution volumes and concentrations; using titration data
Calculating empirical and molecular formulae from data
Calculating percentage yield, composition and purity
All students cover
Electrolysis as the decomposition of an ionic compound (molten or aqueous) by an electric current; anode, cathode and electrolyte
Products from electrolysing molten lead(II) bromide, concentrated aqueous sodium chloride and dilute sulfuric acid; predicting products for a molten binary compound
Electroplating
Hydrogen–oxygen fuel cells: electricity produced, water as the only product
Extended students also cover Extended
Electrolysis of aqueous copper(II) sulfate with inert and with copper electrodes
Predicting products for halide compounds in dilute or concentrated solution
Constructing ionic half-equations for anode and cathode
Describing charge transfer during electrolysis
Comparing fuel cells with petrol engines
All students cover
Exothermic and endothermic reactions defined by their effect on surroundings temperature
Interpreting reaction pathway diagrams
Extended students also cover Extended
Enthalpy change (ΔH) and its sign for exothermic and endothermic reactions
Activation energy (Eᵃ); drawing and labelling reaction pathway diagrams
Bond breaking as endothermic; bond making as exothermic
Calculating enthalpy change using bond energies
All students cover
Physical and chemical changes and their differences
Rate of reaction: effects of concentration, pressure, surface area, temperature and catalysts; practical methods; interpreting rate graphs
Reversible reactions and equilibrium: the ⇋ symbol; the effect of heat on hydrated compounds (copper(II) sulfate, cobalt(II) chloride)
Redox: oxidation numbers (Roman numerals); redox as simultaneous oxidation and reduction; oxidation and reduction defined by gain and loss of oxygen
Extended students also cover Extended
Collision theory: explaining each factor on rate; catalyst lowers activation energy
Conditions for equilibrium; predicting shifts with temperature, pressure, concentration and catalysts
Haber process and Contact process: equations, sources, conditions and reasoning
Redox in terms of electron transfer and oxidation-number changes; colour changes with potassium manganate(VII) and potassium iodide; identifying oxidising and reducing agents
All students cover
Reactions of acids with metals, bases and carbonates; indicators (litmus, thymolphthalein, methyl orange); universal indicator and pH
Bases and alkalis; H⁺ ions in acids and OH⁻ ions in alkalis; neutralisation
Classifying oxides as acidic or basic; metallic vs non-metallic character
Preparation of soluble salts: titration, excess metal, excess insoluble base or carbonate; solubility rules; hydrated and anhydrous substances
Extended students also cover Extended
Acids as proton donors; bases as proton acceptors
Strong and weak acids: complete vs partial dissociation; hydrochloric and ethanoic acid as examples
Amphoteric oxides: Al₂O₃ and ZnO
Insoluble salts prepared by precipitation
Water of crystallisation
All students cover
Arrangement of elements by proton number; metallic to non-metallic change across a period; group number and ionic charge
Group I (alkali metals) trends; Group VII (halogens) trends, appearances and displacement reactions
Transition elements: high densities and melting points, coloured compounds, catalytic behaviour
Noble gases: unreactive, monatomic
Extended students also cover Extended
Identifying trends within a group from given data
Transition elements as having ions with variable oxidation numbers, including iron(II) and iron(III)
All students cover
Physical properties of metals vs non-metals; reactions of metals with dilute acids, water/steam and oxygen; uses of aluminium and copper linked to properties
Alloys: brass, stainless steel; why alloys are harder and their uses
Reactivity series: order; reactions with water and dilute acid; deducing reactivity from results
Corrosion: conditions for rusting; barrier methods of prevention
Extraction of metals: reactivity and ease of extraction; iron in the blast furnace; aluminium from bauxite by electrolysis
Extended students also cover Extended
Why alloys are harder in terms of structure; relative reactivities via tendency to form ions
Apparent unreactivity of aluminium due to its oxide layer
Sacrificial protection and galvanising
Symbol equations for iron extraction
Detailed extraction of aluminium: role of cryolite, why carbon anodes are replaced, electrode half-equations
All students cover
Water: chemical tests; purity; substances in natural water (beneficial and harmful); treatment of domestic water supply
Fertilisers: ammonium salts and nitrates; the role of NPK fertilisers
Air quality and climate: composition of clean, dry air; sources and adverse effects of CO₂, CO, particulates, methane, NOₓ and SO₂; strategies to reduce these; photosynthesis (word equation)
Extended students also cover Extended
How CO₂ and methane cause global warming
How NOₓ forms in car engines and is removed by catalytic converters
Symbol equation for photosynthesis
All students cover
Formulae and functional groups: displayed formulae; general formulae for alkanes, alkenes, alcohols and carboxylic acids; homologous series; saturated vs unsaturated
Naming and drawing methane, ethane, ethene, ethanol and ethanoic acid
Fuels: fossil fuels; hydrocarbons; fractional distillation of petroleum; properties and uses of each fraction
Alkanes: single covalent bonding; combustion and substitution by chlorine
Alkenes: the C=C double bond; cracking of larger alkanes; bromine-water test for unsaturation
Alcohols: manufacture of ethanol (fermentation and catalytic addition of steam); combustion; uses
Carboxylic acids: reactions of ethanoic acid with metals, bases and carbonates
Polymers: monomers and polymers; addition polymerisation of poly(ethene); environmental challenges of plastic disposal
Extended students also cover Extended
Structural formulae and structural isomers; general characteristics of a homologous series
Naming and drawing unbranched alkanes, alkenes, alcohols, carboxylic acids and esters (up to four carbons)
Substitution reactions of alkanes as photochemical reactions
Addition reactions of alkenes: with bromine, hydrogen and steam
Advantages and disadvantages of the two ethanol manufacturing routes
Oxidation of ethanol to ethanoic acid; ester formation
Condensation polymers: repeat units and linkages; nylon and PET; proteins as natural polyamides; differences between addition and condensation polymerisation
All students cover
Experimental design: naming appropriate apparatus for time, temperature, mass and volume; suggesting method advantages and disadvantages; key terms (solvent, solute, solution, saturated solution, residue, filtrate)
Acid–base titrations: burette, pipette and indicator; identifying the end-point
Separation and purification: filtration, crystallisation, simple and fractional distillation; assessing purity from melting and boiling points
Identification of ions and gases: tests for common anions, cations (with NaOH and NH₃), gases, and flame tests for metal ions
Extended students also cover Extended
Separating colourless substances by chromatography using a locating agent
Stating and using the equation for the Rᵉ value
Exam Technique
Command words, and why they decide marks
Cambridge uses a fixed set of command words in its questions. Each one tells the student exactly what kind of answer is expected. Reading them correctly is one of the simplest ways to avoid losing marks.
Command word
What it asks the student to do
State
Express in clear terms (short, direct answer)
Describe
State the main points; give characteristics and main features
Explain
Set out reasons or say why and how, with supporting evidence
Define
Give a precise meaning
Identify / Give
Name, select or recognise; produce an answer from a source or from memory
Calculate
Work out from given facts, figures or information
Determine
Establish an answer using the information available
Deduce
Conclude from available information
Predict
Suggest what may happen, based on available information
Suggest
Apply knowledge to an unfamiliar situation where several answers may be valid
Compare / Contrast
Comment on similarities and/or differences between two things
Sketch
Make a simple freehand drawing showing the key features
Show (that)
Provide structured evidence leading to a given result
Why this matters
“State” and “Give” expect a short, direct answer. “Explain” expects reasoning, a because. “Describe” asks what happens; “Explain” asks why. “Suggest” signals an unfamiliar context where students must apply what they know rather than recall a fact. A student who treats these the same will lose marks even when they understand the chemistry.
Results
How IGCSE Chemistry is graded
Cambridge IGCSE Chemistry is reported on the standard A* to G scale, with U meaning ungraded. A* is the highest and G the lowest classified grade. Core candidates can achieve C to G; Extended candidates can achieve A* to G. Grades are set using thresholds decided after each exam series, so the exact marks needed vary from session to session.
Full grading guide
For the full picture, including how grade boundaries are set, what a “pass” really means and what each grade signals to universities, read The IGCSE Grading System Explained.
How to Do Well
Seven things that actually move grades
1
Respect the practical
A fifth of the grade is AO3. Whether a student sits Paper 5 or Paper 6, they need real familiarity with apparatus, observations, safety, recording data and evaluating methods, this cannot be crammed from a textbook alone.
2
Don’t underestimate multiple choice
Paper 1 or 2 is worth 30% and covers the whole syllabus. Careless mistakes here cost as much as they do anywhere else, and there is no partial credit.
3
Master the theory paper
At 50%, the theory paper is the single biggest component. Structured questions reward clear, complete answers with correct terminology and balanced equations.
4
Answer the command word
Read whether a question says “state”, “describe”, “explain” or “suggest”, and respond accordingly. An explain answer without a because rarely scores full marks.
5
Learn the equations and the tests
Balanced symbol equations, ionic half-equations (Extended) and the ion, gas and flame tests come up repeatedly. The qualitative-analysis notes are provided, but students must use them fluently, not hunt for the right row under time pressure.
6
Understand, don’t memorise
Questions often place familiar chemistry in unfamiliar contexts. Real understanding, knowing why a reaction happens, not just that it does, holds up where rote learning fails.
7
Practise past papers under timed conditions
This is the single most effective way to build accuracy, pacing and mark-scheme awareness. Reading the mark scheme teaches students what Cambridge considers a complete answer, as valuable as sitting the paper itself.
This is exactly what we teach.
Brainiac’s small-group IGCSE Chemistry classes are built around mark-scheme mastery, past-paper practice and practical understanding. Our holiday crash courses are designed to close gaps and sharpen exam technique before the exams.
Students beginning the course should have followed a broad curriculum such as the Cambridge Lower Secondary programme or an equivalent framework.
Combining subjects
0620 cannot be taken in the same series as Cambridge IGCSE (9–1) Chemistry (0971), Physical Science (0652), Combined Science (0653), Co-ordinated Sciences (0654 and 0973), O Level Chemistry (5070) or O Level Combined Science (5129).
Group award
A strong set of IGCSEs including Chemistry can count toward the Cambridge ICE (International Certificate of Education) group award.
Retakes
Candidates can retake the whole qualification as many times as they wish.
Private candidates
Private candidates can enter for this syllabus.
Questions
Frequently asked questions
Is IGCSE Chemistry hard?
▾
It is challenging but very achievable with good teaching and consistent practice. The content is broad, and the practical component means students need hands-on skills as well as theory, but strong exam technique, showing reasoning, writing balanced equations and answering the command word, makes a bigger difference than the raw difficulty of the topics.
What is the difference between Core and Extended?
▾
Core covers the essentials and is graded C to G. Extended covers the Core plus the more demanding Supplement content (including the mole, ionic half-equations, collision theory and condensation polymers) and is graded A* to G. Students aiming for top grades or moving on to A-Level or IB sciences should take Extended.
Do students have to do a laboratory practical exam?
▾
Every candidate takes one practical paper, but schools choose between Paper 5 (a hands-on lab test) and Paper 6 (a written Alternative to Practical). Both are worth 20% and assess the same experimental skills. Students take one, not both. Private and online students typically sit Paper 6.
Can students use a calculator?
▾
Yes. Calculators may be used in all parts of the Chemistry examination, there is no non-calculator paper.
Is a data booklet or Periodic Table provided?
▾
A Periodic Table is provided in all papers. The practical papers also include standard “Notes for use in qualitative analysis” covering ion tests, gas tests and flame tests. Students still need to know how to use these confidently under exam conditions.
How many topics are there in IGCSE Chemistry?
▾
Twelve: States of matter; Atoms, elements and compounds; Stoichiometry; Electrochemistry; Chemical energetics; Chemical reactions; Acids, bases and salts; The Periodic Table; Metals; Chemistry of the environment; Organic chemistry; and Experimental techniques and chemical analysis.
What grade does my child need for A-Level or IB Chemistry?
▾
Requirements vary by school and course, but a grade C is a common minimum and competitive A-Level and IB Chemistry courses usually expect a B or above, which means taking the Extended tier. For more on grades, see The IGCSE Grading System Explained.
Sources & note: This guide is based on the official Cambridge IGCSE Chemistry 0620 syllabus for 2026, 2027 and 2028 (Cambridge Assessment International Education). Syllabus content, exam formats and grade thresholds can change, always check the latest official syllabus for your child’s exam series at the Cambridge International website. This is general information, not official examination guidance.
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