A-Level Chemistry Revision Notes

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Free, syllabus-aligned notes for Cambridge International AS & A Level Chemistry (9701) — 51 topics covering AS Level, each with worked examples and exam tips.

Syllabus-aligned (2025–2027) Worked examples Clear diagrams 100% free
51
Topics
51
AS topics
17
Topics with diagrams
201
Learning objectives

These revision notes work through the AS Level part of the Cambridge International AS & A Level Chemistry (9701) syllabus, one topic at a time. They are written for students who want a clear, exam-focused summary of each part of the course — what you need to know, how it is tested, and the mistakes that cost marks. Use them alongside your textbook and past papers as you revise.

These notes cover AS Level (Units 1–22, examined in Papers 1–3). The A2 Level units (Papers 4–5) are not covered here yet. Browse by unit below, or jump straight to a topic. Every note is free and needs no sign-up.

How to get the most from these notes

1. Learn the definitions

Read the key definitions, then close the page and write them from memory. Precise wording earns marks.

2. Do the worked example

Try each exam-style question before reading the model answer, then compare your method line by line.

3. Avoid the common mistakes

Check your answers against the common-mistakes list and watch the command words in each question.

AS Level

Papers 1, 2 & 3 — Units 1–22

1. Atomic structure

1.1 AS

Particles in the atom and atomic radius

7 objectives
1.2 AS

Isotopes

4 objectives
1.3 AS

Electrons, energy levels and atomic orbitals

9 objectives
1.4 AS

Ionisation energy

8 objectives

2. Atoms, molecules and stoichiometry

2.1 AS

Relative masses of atoms and molecules

2 objectives
2.2 AS

The mole and the Avogadro constant

1 objective
2.3 AS

Formulas

5 objectives
2.4 AS

Reacting masses and volumes (of solutions and gases)

1 objective

3. Chemical bonding

3.1 AS

Electronegativity and bonding

4 objectives
3.2 AS

Ionic bonding

2 objectives
3.3 AS

Metallic bonding

1 objective
3.4 AS

Covalent bonding and coordinate (dative covalent) bonding

3 objectives
3.5 AS

Shapes of molecules

2 objectives
3.6 AS

Intermolecular forces, electronegativity and bond properties

4 objectives
3.7 AS

Dot-and-cross diagrams

1 objective

4. States of matter

4.1 AS

The gaseous state: ideal and real gases and pV = nRT

3 objectives
4.2 AS

Bonding and structure

3 objectives

5. Chemical energetics

5.1 AS

Enthalpy change, ΔH

7 objectives
5.2 AS

Hess’s law

2 objectives

6. Electrochemistry

6.1 AS

Redox processes: electron transfer and changes in oxidation number (oxidation state)

5 objectives

7. Equilibria

7.1 AS

Chemical equilibria: reversible reactions, dynamic equilibrium

10 objectives
7.2 AS

Brønsted–Lowry theory of acids and bases

10 objectives

8. Reaction kinetics

8.1 AS

Rate of reaction

3 objectives
8.2 AS

Effect of temperature on reaction rates and the concept of activation energy

3 objectives
8.3 AS

Homogeneous and heterogeneous catalysts

1 objective

9. The Periodic Table: chemical periodicity

9.1 AS

Periodicity of physical properties of the elements in Period 3

2 objectives
9.2 AS

Periodicity of chemical properties of the elements in Period 3

7 objectives
9.3 AS

Chemical periodicity of other elements

2 objectives

10. Group 2

10.1 AS

Similarities and trends in the properties of the Group 2 metals, magnesium to barium, and their compounds

5 objectives

11. Group 17

11.1 AS

Physical properties of the Group 17 elements

3 objectives
11.2 AS

The chemical properties of the halogen elements and the hydrogen halides

3 objectives
11.3 AS

Some reactions of the halide ions

2 objectives
11.4 AS

The reactions of chlorine

2 objectives

12. Nitrogen and sulfur

12.1 AS

Nitrogen and sulfur

5 objectives

13. An introduction to AS Level organic chemistry

13.1 AS

Formulas, functional groups and the naming of organic compounds

6 objectives
13.2 AS

Characteristic organic reactions

2 objectives
13.3 AS

Shapes of organic molecules; σ and π bonds

4 objectives
13.4 AS

Isomerism: structural isomerism and stereoisomerism

6 objectives

14. Hydrocarbons

14.1 AS

Alkanes

6 objectives
14.2 AS

Alkenes

5 objectives

15. Halogen compounds

15.1 AS

Halogenoalkanes

7 objectives

16. Hydroxy compounds

16.1 AS

Alcohols

5 objectives

17. Carbonyl compounds

17.1 AS

Aldehydes and ketones

6 objectives

18. Carboxylic acids and derivatives

18.1 AS

Carboxylic acids

2 objectives
18.2 AS

Esters

2 objectives

19. Nitrogen compounds

19.1 AS

Primary amines

1 objective
19.2 AS

Nitriles and hydroxynitriles

3 objectives

20. Polymerisation

20.1 AS

Addition polymerisation

4 objectives

21. Organic synthesis

21.1 AS

Organic synthesis

3 objectives

22. Analytical techniques

22.1 AS

Infrared spectroscopy

1 objective
22.2 AS

Mass spectrometry

6 objectives

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What every topic includes

These notes are in beta: they are generated with AI from the published syllabus objectives and reviewed for accuracy, and we keep improving them. Always check the exact requirements for your exam with your teacher or the official syllabus.

Frequently asked questions

Are these A-Level Chemistry revision notes free? ▾

Yes. All 51 topic guides are free to read in full, with no account or sign-up needed. Each one covers the key definitions, core content, worked examples, common mistakes and exam tips for that part of the Cambridge 9701 syllabus.

How is the Cambridge A-Level Chemistry (9701) exam structured? ▾

Cambridge assesses Chemistry through five papers. At AS Level, Paper 1 is multiple choice, Paper 2 is structured questions, and Paper 3 tests advanced practical skills. At A2 Level, Paper 4 is structured questions on the whole syllabus and Paper 5 tests planning, analysis and evaluation. Your AS and A2 papers together make up the full A Level.

What is the difference between AS Level and A2 Level? ▾

AS Level is the first half of the course (Papers 1–3) and can be certificated on its own. A2 Level is the second half (Papers 4–5) and builds on the AS content; together they form the full A Level. This page currently covers the AS Level topics.

What does each revision note include? ▾

Every topic follows the same layout: an overview, key definitions in exam-precise language, the core content explained step by step, at least one worked exam-style question with a model answer, the relevant equations, a list of common mistakes to avoid, and targeted exam tips. Many topics also include a clear, labelled graph to illustrate the idea.

What is the best way to revise A-Level Chemistry? ▾

Active recall beats re-reading. Use a note to learn its definitions precisely, then close it and write them from memory. Work through the worked example, then attempt past-paper questions on the same topic. Watch the command words — "describe", "explain", "compare" and "calculate" each expect a different kind of answer — and check your wording against the common-mistakes list.

Do these notes follow the latest syllabus? ▾

Yes. The topics and learning objectives are aligned to the current Cambridge International AS & A Level Chemistry (9701) syllabus for 2025–2027. Always confirm the exact content for your exam session with your teacher or the official syllabus.

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