Cambridge IGCSE · 0620 · Data 2020–2025
Most-tested topics in IGCSE Chemistry
Just 3 chapters — Organic chemistry, Experimental techniques and chemical analysis, Acids, bases and salts — carry about 42% of all the marks. Revise those first.
Based on 248 real Cambridge past papers and 39,519 tagged marks, 2020–2025. Ranked by marks, not guesswork.
Historical counts from past papers — not an exam prediction. Download the data (CSV)
Revise these first
The topics that carry the most marks, highest first. Each opens the free past-paper questions.
- 1Practise →Experimental techniques and chemical analysisEvery year
- 2Practise →Acids, bases and saltsEvery year
- 3Practise →7.4 Identification of ions and gases5% of marksAcids, bases and saltsEvery year
- 4Practise →12.5 Chemical tests and qualitative analysis4% of marksExperimental techniques and chemical analysisEvery year
- 5Practise →6.2 Rate of reaction4% of marksChemical reactionsEvery year
- 6Practise →Organic chemistryEvery year
- 7Practise →1.1 Solids, liquids and gases3% of marksStates of matterEvery year
- 8Practise →2.4 Ions and ionic bonds3% of marksAtoms, elements and compoundsEvery year
See the full breakdown — all 55 topics across 12 chapters
Organic chemistry
15% of marks- 11.1 Formulae, functional groups and terminologyEvery year1287 marks · 282 qs
- 11.4 AlkenesEvery year1034 marks · 278 qs
- 11.5 AlcoholsEvery year1020 marks · 263 qs
- 11.6 Carboxylic acidsEvery year796 marks · 182 qs
- 11.3 AlkanesEvery year733 marks · 245 qs
- 11.2 Fossil fuelsEvery year518 marks · 162 qs
- 11.7 PolymersEvery year509 marks · 161 qs
Experimental techniques and chemical analysis
14% of marks- 12.1 Experimental design, apparatus and measurementsEvery year2544 marks · 295 qs
- 12.5 Chemical tests and qualitative analysisEvery year1505 marks · 197 qs
- 12.2 Separation and purificationEvery year1067 marks · 253 qs
- 12.3 ChromatographyEvery year165 marks · 76 qs
- 12.4 Locating agents and purityEvery year67 marks · 34 qs
Acids, bases and salts
13% of marks- 7.1 Characteristic properties of acids and basesEvery year2009 marks · 427 qs
- 7.4 Identification of ions and gasesEvery year1915 marks · 280 qs
- 7.3 Preparation of saltsEvery year977 marks · 176 qs
- 7.2 OxidesEvery year413 marks · 149 qs
Atoms, elements and compounds
13% of marks- 2.4 Ions and ionic bondsEvery year1164 marks · 259 qs
- 2.5 Simple molecules and covalent bondsEvery year1071 marks · 199 qs
- 2.2 Atomic structure and the Periodic TableEvery year1043 marks · 242 qs
- 2.3 IsotopesEvery year764 marks · 136 qs
- 2.1 Elements, compounds and mixturesEvery year437 marks · 114 qs
- 2.6 Giant covalent structuresEvery year308 marks · 106 qs
- 2.7 Metallic bondingEvery year211 marks · 45 qs
Stoichiometry
9% of marks- 3.1 FormulaeEvery year1060 marks · 202 qs
- 3.2 Relative massesEvery year956 marks · 141 qs
- 3.4 Reacting massesEvery year604 marks · 107 qs
- 3.5 Solutions and concentrationEvery year575 marks · 60 qs
- 3.3 The mole and Avogadro constantEvery year370 marks · 57 qs
Chemical reactions
9% of marks- 6.2 Rate of reactionEvery year1492 marks · 265 qs
- 6.4 RedoxEvery year1107 marks · 258 qs
- 6.3 Reversible reactions and equilibriumEvery year575 marks · 123 qs
- 6.1 Physical and chemical changesEvery year241 marks · 105 qs
Metals
7% of marks- 9.3 Extraction of metalsEvery year871 marks · 180 qs
- 9.1 Properties of metalsEvery year786 marks · 268 qs
- 9.2 Reactivity seriesEvery year591 marks · 171 qs
- 9.4 Uses of metalsEvery year397 marks · 112 qs
The Periodic Table
6% of marks- 8.2 Group I propertiesEvery year677 marks · 143 qs
- 8.5 Transition elementsEvery year550 marks · 120 qs
- 8.3 Group VII propertiesEvery year531 marks · 134 qs
- 8.1 Arrangement of elementsEvery year351 marks · 178 qs
- 8.4 Noble gasesEvery year190 marks · 80 qs
Chemical energetics
4% of marks- 5.1 Exothermic and endothermic reactionsEvery year1116 marks · 220 qs
- 5.2 Energy level diagramsEvery year292 marks · 68 qs
- 5.3 Bond energiesEvery year199 marks · 47 qs
Electrochemistry
4% of marks- 4.1 Electrolysis of molten compoundsEvery year625 marks · 125 qs
- 4.2 Electrolysis of aqueous solutionsEvery year361 marks · 117 qs
- 4.5 Ionic half-equationsEvery year357 marks · 62 qs
- 4.4 ElectroplatingEvery year101 marks · 24 qs
- 4.6 Fuel cellsEvery year77 marks · 48 qs
- 4.3 Electrolysis of brineEvery year41 marks · 27 qs
Chemistry of the environment
4% of marks- 10.3 Air quality and climateEvery year942 marks · 241 qs
- 10.1 WaterEvery year276 marks · 82 qs
- 10.2 FertilisersEvery year269 marks · 76 qs
States of matter
3% of marks- 1.1 Solids, liquids and gasesEvery year1171 marks · 228 qs
- 1.2 DiffusionEvery year211 marks · 57 qs
Turn the data into practice
Every topic above is drawn from real Cambridge IGCSE Chemistry papers, tagged to the syllabus. Students can drill the high-frequency topics in the free bank; teachers can turn any of them into a ready-to-print worksheet in seconds. Or explore the full six-year trends in the interactive records.