We counted every question in our own IGCSE Chemistry 0620 question bank — 1,695 questions worth 3,751 marks, 2022 to 2026 — and sorted them into the 12 chapters of the syllabus. Organic Chemistry carries the most marks.
Method. Counted across 1,695 questions worth 3,751 marks, drawn from 64 Cambridge IGCSE Chemistry 0620 papers, 2022 to 2026. Compiled by ExamYard from its own question bank, in which every question is tagged to the syllabus chapter it tests. Last recounted 16 October 2026.
Every chapter, biggest first
| Chapter | Questions | Marks | Marks a question | Share | |
|---|---|---|---|---|---|
| Organic Chemistry | 267 | 681 | 2.6 | 18.2% | |
| Atoms, Elements and Compounds | 228 | 592 | 2.6 | 15.8% | |
| Chemical Reactions | 189 | 507 | 2.7 | 13.5% | |
| Stoichiometry | 162 | 395 | 2.4 | 10.5% | |
| Acids, Bases and Salts | 144 | 340 | 2.4 | 9.1% | |
| Metals | 161 | 316 | 2.0 | 8.4% | |
| The Periodic Table | 121 | 226 | 1.9 | 6.0% | |
| Electrochemistry | 85 | 191 | 2.2 | 5.1% | |
| Chemistry of the Environment | 108 | 152 | 1.4 | 4.1% | |
| Experimental Techniques and Chemical Analysis | 100 | 146 | 1.5 | 3.9% | |
| Chemical Energetics | 63 | 124 | 2.0 | 3.3% | |
| States of Matter | 67 | 81 | 1.2 | 2.2% |
The top 4 of 12 chapters hold half the marks in the bank. The three heaviest are Organic Chemistry, Atoms, Elements and Compounds, Chemical Reactions. The lightest is States of Matter, at 2.2% of the marks.
Inside the chapters
| Sub-topic | Chapter | Questions | Marks |
|---|---|---|---|
| Haber and Contact processes | Chemical Reactions | 50 | 170 |
| Position of equilibrium | Chemical Reactions | 34 | 136 |
| Isotopes | Atoms, Elements and Compounds | 28 | 119 |
| Ionic bonding | Atoms, Elements and Compounds | 27 | 105 |
| Esters and esterification | Organic Chemistry | 23 | 103 |
| Protons, neutrons and electrons | Atoms, Elements and Compounds | 36 | 102 |
| Blast furnace extraction of iron | Metals | 26 | 95 |
| Preparing insoluble salts | Acids, Bases and Salts | 24 | 89 |
| Bond energy calculations | Chemical Energetics | 29 | 81 |
| Manufacture of ethanol | Organic Chemistry | 24 | 79 |
What the numbers say
Organic Chemistry is the biggest chapter in IGCSE Chemistry 0620: 681 marks across 267 questions, 18.2% of everything in the bank. States of Matter is the lightest at 2.2%. Put another way, for every ten hours you spend on this subject, about 2 of them belong to the first chapter alone if you follow the marks.
7 of the 12 chapters carry 80% of the marks between them. That is the short list worth knowing cold. The remaining 5 still appear, and Cambridge can set anything on the syllabus, so they are the ones to revise last rather than the ones to drop.
The marks a question column is worth a second look. Chemical Reactions averages 2.7 marks a question, the longest answers in the subject, so each one needs method and working rather than a quick line. States of Matter averages 1.2, which means short, frequent questions where speed and accuracy pay. The two need different kinds of practice.
Common questions
Organic Chemistry. It holds 267 questions worth 681 marks, which is 18.2% of the marks in our IGCSE Chemistry 0620 bank. The next two are Atoms, Elements and Compounds and Chemical Reactions.
7 of the 12 chapters carry 80% of the marks between them.
States of Matter, at 2.2% of the marks. That is the chapter to revise last rather than the one to drop, because Cambridge can set anything on the syllabus.
Counted across 1,695 questions worth 3,751 marks, drawn from 64 Cambridge IGCSE Chemistry 0620 papers, 2022 to 2026. Compiled by ExamYard from its own question bank, in which every question is tagged to the syllabus chapter it tests. Last recounted 16 October 2026.
How to use this
Revise the biggest chapters first. A chapter worth 18% of the marks deserves more than one worth 2.2%.
Use it to decide what to practise, not what to skip. A light chapter can still be the difference between two grades, and Cambridge can set anything on the syllabus.
Check yourself chapter by chapter rather than by whole papers, so a weak topic shows up while there is still time to fix it.
These are ExamYard’s own figures: the questions in our IGCSE Chemistry 0620 question bank, grouped into the chapter of the syllabus each one tests, and added up by the marks each carries. No question text, mark scheme or examiner report is reproduced on this page. The printed book and the online bank are counted separately, so the totals on this page need not match the book’s own page.