We counted every question in our own AS Level Chemistry 9701 question bank — 313 questions worth 1,496 marks, 2023 to 2026 — and sorted them into the 22 chapters of the syllabus. Chemical Periodicity carries the most marks.
Method. Counted across 313 questions worth 1,496 marks, drawn from 25 Cambridge AS Level Chemistry 9701 papers, 2023 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 | |
|---|---|---|---|---|---|
| Chemical Periodicity | 27 | 172 | 6.4 | 11.5% | |
| Hydrocarbons | 25 | 145 | 5.8 | 9.7% | |
| Atomic Structure | 23 | 126 | 5.5 | 8.4% | |
| Equilibria | 17 | 101 | 5.9 | 6.8% | |
| Chemical Bonding | 26 | 92 | 3.5 | 6.1% | |
| Group 17 | 15 | 86 | 5.7 | 5.7% | |
| Analytical Techniques | 21 | 73 | 3.5 | 4.9% | |
| An Introduction to AS Level Organic Chemistry | 18 | 71 | 3.9 | 4.7% | |
| Hydroxy Compounds | 13 | 66 | 5.1 | 4.4% | |
| Chemical Energetics | 13 | 64 | 4.9 | 4.3% | |
| Carboxylic Acids and Derivatives | 12 | 61 | 5.1 | 4.1% | |
| Atoms, Molecules and Stoichiometry | 15 | 60 | 4.0 | 4.0% | |
| Carbonyl Compounds | 9 | 54 | 6.0 | 3.6% | |
| Reaction Kinetics | 11 | 48 | 4.4 | 3.2% | |
| States of Matter | 11 | 47 | 4.3 | 3.1% | |
| Halogen Compounds | 10 | 47 | 4.7 | 3.1% | |
| Nitrogen and Sulfur | 10 | 45 | 4.5 | 3.0% | |
| Group 2 | 12 | 43 | 3.6 | 2.9% | |
| Nitrogen Compounds | 8 | 35 | 4.4 | 2.3% | |
| Organic Synthesis | 7 | 30 | 4.3 | 2.0% | |
| Electrochemistry | 6 | 17 | 2.8 | 1.1% | |
| Polymerisation | 4 | 13 | 3.2 | 0.9% |
The top 7 of 22 chapters hold half the marks in the bank. The three heaviest are Chemical Periodicity, Hydrocarbons, Atomic Structure. The lightest is Polymerisation, at 0.9% of the marks.
Inside the chapters
| Sub-topic | Chapter | Questions | Marks |
|---|---|---|---|
| Chlorides of Period 3 | Chemical Periodicity | 10 | 60 |
| Free-radical substitution | Hydrocarbons | 7 | 40 |
| Addition of hydrogen halides | Hydrocarbons | 5 | 40 |
| First ionisation energy | Atomic Structure | 4 | 40 |
| Oxides of nitrogen and air pollution | Nitrogen and Sulfur | 7 | 35 |
| Melting point and electrical conductivity | Chemical Periodicity | 4 | 34 |
| Routes through a nitrile | Nitrogen Compounds | 7 | 31 |
| Successive ionisation energies | Atomic Structure | 6 | 31 |
| Oxides of Period 3 | Chemical Periodicity | 6 | 31 |
| Carbon atoms from the M+1 peak | Analytical Techniques | 7 | 30 |
What the numbers say
Chemical Periodicity is the biggest chapter in AS Level Chemistry 9701: 172 marks across 27 questions, 11.5% of everything in the bank. Polymerisation is the lightest at 0.9%. Put another way, for every ten hours you spend on this subject, about 1 of them belong to the first chapter alone if you follow the marks.
14 of the 22 chapters carry 80% of the marks between them. That is the short list worth knowing cold. The remaining 8 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 Periodicity averages 6.4 marks a question, the longest answers in the subject, so each one needs method and working rather than a quick line. Electrochemistry averages 2.8, which means short, frequent questions where speed and accuracy pay. The two need different kinds of practice.
Common questions
Chemical Periodicity. It holds 27 questions worth 172 marks, which is 11.5% of the marks in our AS Level Chemistry 9701 bank. The next two are Hydrocarbons and Atomic Structure.
14 of the 22 chapters carry 80% of the marks between them.
Polymerisation, at 0.9% 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 313 questions worth 1,496 marks, drawn from 25 Cambridge AS Level Chemistry 9701 papers, 2023 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 11% of the marks deserves more than one worth 0.9%.
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 AS Level Chemistry 9701 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.