IGCSE Chemistry Lesson Notes
The full Cambridge IGCSE Chemistry (0620) syllabus, from atomic structure to organic reactions — including the moles work and equation-balancing that lessons spend the most time on.
All 47 topics across 14 units
Start anywhere — each topic stands on its own.
States of matter
2 topics-
Diffusion
Diffusion: what it is, how the particle model explains it, the effect of temperature and state, and why lighter molecules diffuse faster.
5 min read Read notes -
Kinetic particle theory and changes of state
States of matter: particle arrangement in solids, liquids and gases, all six changes of state, heating and cooling curves, and the effect of temperature and pressure.
8 min read Read notes
Atoms, elements and compounds
6 topics-
Atomic structure and isotopes
Atomic structure: protons, neutrons and electrons, proton and nucleon number, working out neutrons, isotopes, ions and relative atomic mass calculations.
8 min read Read notes -
Covalent bonding
Covalent bonding: shared electron pairs, dot-and-cross diagrams, single and double bonds, and why simple molecular substances have low melting points.
7 min read Read notes -
Electronic configuration
Electronic configuration: filling electron shells, writing configurations for the first 20 elements, ions, and finding group and period from the configuration.
5 min read Read notes -
Giant covalent structures
Giant covalent structures: the bonding in diamond, graphite and silicon dioxide, and how their structures explain hardness, melting point and conductivity.
6 min read Read notes -
Ions and ionic bonding
Ionic bonding: how ions form by electron transfer, dot-and-cross diagrams, the giant ionic lattice, and explaining melting points, conductivity and solubility.
8 min read Read notes -
Metallic bonding
Metallic bonding: the lattice of positive ions in a sea of delocalised electrons, and how it explains conductivity, malleability and high melting points.
5 min read Read notes
Stoichiometry
7 topics-
Chemical formulae and balancing equations
Writing formulae and balancing equations: ionic charges, polyatomic ions and brackets, the diatomic elements, balancing method and state symbols.
7 min read Read notes -
Elements, compounds and mixtures
Classifying matter: the definitions of element, compound and mixture, how to tell them apart, and why compounds differ from mixtures of the same elements.
5 min read Read notes - Extended
Empirical and molecular formulae
Empirical and molecular formulae: the difference between them, calculating from masses or percentages, handling awkward ratios, and finding the molecular formula from Mr.
6 min read Read notes - Extended
Percentage yield, purity and gas volumes
Percentage yield and purity, why yields are below 100%, and gas volume calculations using the molar gas volume of 24 dm³ at r.t.p.
6 min read Read notes - Extended
Reacting masses and limiting reactants
Reacting masses: using the mole ratio, identifying the limiting reactant and the reactant in excess, and calculating the mass of product formed.
6 min read Read notes -
Relative masses and concentration of solutions
Relative masses and concentration: calculating Ar and Mr, percentage composition, concentration in mol/dm³ and g/dm³, and dilution.
5 min read Read notes - Extended
The mole, Avogadro constant and mole calculations
The mole: the Avogadro constant, moles from mass, concentration and gas volume, molar mass, and the unit conversions that cost marks.
6 min read Read notes
Electrochemistry
3 topics-
Electrolysis of molten and aqueous compounds
Predicting electrolysis products: molten compounds, aqueous solutions, the effect of the reactivity series and concentration, half-equations and observations.
6 min read Read notes -
Electrolysis principles
Electrolysis: electrolytes and electrodes, anode and cathode, why molten and aqueous compounds conduct, half-equations and predicting the products.
7 min read Read notes -
Electroplating, purification and fuel cells
Applied electrochemistry: electroplating with active electrodes, purifying copper, simple cells, and the hydrogen–oxygen fuel cell with its advantages.
6 min read Read notes
Chemical energetics
2 topics- Extended
Bond energy calculations
Bond energies: the energy needed to break and released on making bonds, calculating the enthalpy change of a reaction, and interpreting the sign.
5 min read Read notes -
Exothermic and endothermic reactions
Energetics: exothermic and endothermic reactions, energy level diagrams, activation energy, bond breaking and making, and enthalpy change.
6 min read Read notes
Chemical reactions
3 topics-
Rate of reaction and collision theory
Rate of reaction: collision theory, the effects of concentration, temperature, surface area, pressure and catalysts, and interpreting rate graphs.
6 min read Read notes -
Redox, oxidation numbers and oxidising agents
Redox: OIL RIG, the rules for assigning oxidation numbers, identifying what is oxidised and reduced, oxidising and reducing agents, and half-equations.
8 min read Read notes - Extended
Reversible reactions and equilibrium
Equilibrium: reversible reactions, dynamic equilibrium, Le Chatelier's principle for temperature, pressure and concentration, and the Haber and Contact processes.
7 min read Read notes
Acids, bases and salts
6 topics-
Acids, bases and alkalis, pH and indicators
Acids and bases: the pH scale, indicators and their colours, strong vs weak acids, proton donors and acceptors, and dissociation in water.
6 min read Read notes -
Oxides and Transition elements
Oxides: acidic, basic, amphoteric and neutral oxides and their reactions, plus the properties and uses of the transition elements.
6 min read Read notes -
Preparation of salts
Preparing salts: naming salts, the acid + excess solid method, titration for soluble salts, precipitation for insoluble salts, and solubility rules.
6 min read Read notes -
Reactions of acids
The reactions of acids: with metals, metal oxides, hydroxides and carbonates, the products of each, observations, and neutralisation.
5 min read Read notes -
Solubility rules and precipitation
Solubility: the rules for which salts dissolve, predicting precipitates, writing ionic equations, and using precipitation to identify ions.
5 min read Read notes - Extended
Titration and volumetric analysis
Titration: the apparatus, method, choice of indicator, reading a burette, concordant titres, and calculating an unknown concentration.
7 min read Read notes
The Periodic Table
2 topics-
Group I and Group VII
Group I and Group VII: physical properties, reactions with water, trends in reactivity down each group and why they run in opposite directions, and halogen displacement.
6 min read Read notes -
Structure, trends and classification
The Periodic Table: groups and periods, metals and non-metals, predicting properties from position, trends in atomic size and reactivity, and the noble gases.
7 min read Read notes
Metals
3 topics-
Extraction of metals and the blast furnace
Metal extraction: choosing the method from the reactivity series, the blast furnace reactions in order, the role of coke and limestone, and extracting aluminium.
6 min read Read notes -
Reactivity series and displacement reactions
The reactivity series: the order of metals, reactions with water, steam and acids, displacement reactions, ionic equations and the aluminium oxide layer.
6 min read Read notes -
Rusting, corrosion and alloys
Rusting: the conditions required, the experiment proving them, methods of prevention including sacrificial protection, and the structure and uses of alloys.
6 min read Read notes
Chemistry of the environment
1 topic-
Air, water and fertilisers
The environment: air composition and pollutants, acid rain, climate change, catalytic converters, water treatment and testing, and NPK fertilisers.
6 min read Read notes
Organic chemistry
7 topics-
Alcohols, fermentation and ethanol
Alcohols: the homologous series and naming, combustion and oxidation, and the two industrial routes to ethanol — fermentation and the hydration of ethene.
6 min read Read notes -
Alkanes and substitution
Alkanes: the general formula and naming, saturated structure, combustion, substitution with chlorine in UV light, and why alkanes are unreactive.
5 min read Read notes -
Alkenes and addition reactions
Alkenes: the general formula, saturated vs unsaturated, addition reactions with bromine, hydrogen and steam, the bromine water test and cracking.
5 min read Read notes -
Carboxylic acids and esters
Carboxylic acids and esters: the –COOH group, reactions as weak acids, making ethanoic acid by oxidation, esterification and naming esters.
5 min read Read notes -
Crude oil and fuels
Crude oil: fractional distillation, the fractions and their uses, trends in boiling point and viscosity, cracking, and combustion products.
6 min read Read notes -
Homologous series and functional groups
Organic families: what a homologous series is, the general formulae and functional groups, naming, structural and displayed formulae, and isomers.
6 min read Read notes -
Polymers
Polymers: addition polymerisation from alkenes, drawing repeat units, condensation polymerisation, polyesters and polyamides, and plastic pollution.
5 min read Read notes
Chemical analysis
3 topics-
Chromatography
Paper chromatography: the method, why the baseline is pencil, interpreting chromatograms, calculating Rf values, and using locating agents.
5 min read Read notes -
Separation techniques and purification
Separation: filtration, crystallisation, simple and fractional distillation, chromatography, and choosing the right method with purity tests.
6 min read Read notes -
Tests for cations, anions and gases
Qualitative analysis: flame tests, sodium hydroxide and ammonia tests for cations, tests for carbonate, sulfate, halide and nitrate ions, and all the gas tests.
7 min read Read notes
Practical skills
1 topic-
Experiments, apparatus, measurement and graph work
IGCSE Cambridge Chemistry practical paper guidance: choosing apparatus, variables, recording readings, drawing and reading graphs, identifying sources of error, and improving reliability.
8 min read Read notes
Exam skills
1 topic-
Exam technique and past paper strategy
How to earn more marks in IGCSE Cambridge Chemistry: learning definitions precisely, showing working in calculations, equations, the practical paper, multiple choice strategy and using past papers.
7 min read Read notes
Notes get you started. A tutor gets you the grade.
These notes came out of one-to-one Chemistry lessons. If a topic still will not click, sit in one — the first lesson is free.
About these IGCSE Chemistry notes
Do these notes cover the whole Cambridge IGCSE Chemistry syllabus?
Yes — all 47 topics across the 14 units of the undefined syllabus are covered, grouped in the order the syllabus lists them. Nothing is held back behind a sign-up.
Who wrote them?
Tutopiya Chemistry tutors, from their own one-to-one teaching. The emphasis in each topic reflects where students actually struggle rather than how much space a textbook gives it.
How should I use them alongside past papers?
Read the topic first, then attempt questions on it, then come back to the mistakes section at the end of the topic. Most lost marks in a past paper map onto something already listed there.
Are these notes up to date with the 0620 specification?
They follow the current undefined specification. Exam boards do revise syllabuses, so confirm the objectives for your exam session against the official Cambridge specification.
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