Cambridge IGCSE Chemistry Syllabus Guide (0620), 2026–2028
What changed from the 2023–2025 syllabus, how the papers work, all 252 learning objectives by topic, and the key formulas
The Cambridge IGCSE Chemistry syllabus contains 252 learning objectives across 12 main topics. This guide breaks down exactly what you need to know for Core and Supplement (Extended) tiers.
Chemistry is often described as the "central science" - it connects physics to biology and touches everything from medicine to materials. But that breadth means there's a lot to learn: atomic structure, bonding, reactions, organic chemistry, and more.
The key to success? Understanding the syllabus structure. It shows you exactly what's Core vs Supplement-only, which topics have the most learning objectives, and where Extended students need to focus on calculations (like moles and titrations). Many students are surprised to discover that organic chemistry alone makes up 20% of the learning objectives.
This guide helps you see the full picture - so you can study smarter, not just harder. Ready to practice? Try our IGCSE Chemistry past papers.
What Changed for 2026–2028?
Nothing that affects what you learn. The 2026–2028 syllabus covers exams in 2026, 2027 and 2028, and Cambridge states that there are no substantial changes that would affect teaching. Its August 2026 update (version 2) updated the assessment overview on page 9; the papers, marks and timings are the same as in the 2023–2025 syllabus.
We compared the subject content of the 2023–2025 and 2026–2028 syllabuses line by line. There are no content changes: every learning objective is the same and sits in the same Core or Supplement column. The only differences are small wording and formatting edits, for example “Group VIII noble gases have a full outer shell” became “…a full outer electron shell”.
What this means for you
Notes, flashcards and past papers written for the 2023–2025 syllabus are still fully valid for 2026–2028. Past papers from 2023 onwards are the closest practice you can get to your exam.
How the Exam Works (2026–2028)
Every candidate takes three papers: one multiple-choice paper, one theory paper and one practical paper. Which multiple-choice and theory papers you take depends on your tier.
| Paper | Who takes it | Length | Marks | Weighting |
|---|---|---|---|---|
| Paper 1: Multiple Choice (Core) | Core | 45 minutes | 40 | 30% |
| Paper 2: Multiple Choice (Extended) | Extended | 45 minutes | 40 | 30% |
| Paper 3: Theory (Core) | Core | 1 hour 15 minutes | 80 | 50% |
| Paper 4: Theory (Extended) | Extended | 1 hour 15 minutes | 80 | 50% |
| Paper 5: Practical Test | Either tier (your school chooses 5 or 6) | 1 hour 15 minutes | 40 | 20% |
| Paper 6: Alternative to Practical | Either tier (your school chooses 5 or 6) | 1 hour | 40 | 20% |
Calculators may be used in all papers. The question papers include a copy of the Periodic Table (with relative atomic masses) and give the molar gas volume, 24 dm³ at r.t.p. Exams run in the May/June and October/November series, plus a February/March series in India only. See the exam timetables for this year’s dates.
First: Know Your Tier - Core vs Extended
Before diving into the syllabus, you must understand the tier system. Cambridge IGCSE Chemistry offers two levels of difficulty, and you need to know which one you're taking.
Core Tier
Papers 1 and 3, plus Paper 5 or 6
- 154 learning objectives
- Grades available: C to G
- Foundational concepts
- Qualitative understanding
- Basic calculations
- Descriptive answers
Extended Tier
Papers 2 and 4, plus Paper 5 or 6
- 252 learning objectives (all 154 Core + 98 Supplement)
- Grades available: A* to G
- Advanced concepts
- Quantitative analysis
- Complex calculations (moles, titrations)
- Deeper explanations
Important
Your school or exam centre decides which tier you take. If you're aiming for grades A* to B, you must take Extended. Core tier caps at grade C.
Check with your teacher if you're unsure which tier you're registered for.
The 12 Topics: Syllabus Overview
IGCSE Chemistry is organized into 12 main topics covering everything from particle theory to organic chemistry. You'll start with states of matter and build up to understanding atoms and bonding. Then learn about stoichiometry (chemical calculations), electrochemistry, and energy changes. Chemical reactions covers rates and equilibrium. Acids and bases, the Periodic Table, and metals follow. Finally, environmental chemistry, organic chemistry, and experimental techniques complete the syllabus.
Here's how the learning objectives break down across the 12 topics:
| Unit | Topic | Core | Supp | Total | % |
|---|---|---|---|---|---|
| 11 | Organic chemistry | 30 | 20 | 50 | 20% |
| 6 | Chemical reactions | 12 | 21 | 33 | 13% |
| 2 | Atoms, elements and compounds | 18 | 11 | 29 | 12% |
| 9 | Metals | 16 | 7 | 23 | 9% |
| 7 | Acids, bases and salts | 12 | 8 | 20 | 8% |
| 3 | Stoichiometry | 8 | 11 | 19 | 8% |
| 10 | Chemistry of the environment | 15 | 3 | 18 | 7% |
| 12 | Experimental techniques and chemical analysis | 14 | 2 | 16 | 6% |
| 8 | The Periodic Table | 13 | 2 | 15 | 6% |
| 4 | Electrochemistry | 8 | 5 | 13 | 5% |
| 1 | States of matter | 5 | 3 | 8 | 3% |
| 5 | Chemical energetics | 3 | 5 | 8 | 3% |
| TOTAL | 154 | 98 | 252 | 100% | |
Supplement-Only Topics
Some topics are heavily Supplement-only - Core students can skip these:
- 3.3 The mole and Avogadro constant - Mostly Supplement (7 of 8 objectives)
- 6.3 Reversible reactions and equilibrium - Mostly Supplement (9 of 11 objectives)
- 2.7 Metallic bonding - Entirely Supplement
Key Insight: Focus on the Big Three
The top 3 units account for 44% of all learning objectives:
- Organic chemistry (20%) is the largest single topic - alkanes, alkenes, alcohols, polymers
- Chemical reactions (13%) covers rates, equilibrium, and redox
- Atoms, elements and compounds (12%) is foundational to everything else
Master these three units first. Start practicing with our IGCSE Chemistry topic quizzes.
Learning Objectives by Topic (Visual)
Bar length shows total objectives. Color split shows Core vs Supplement.
Key Formulas and Calculations
Unlike Physics, Chemistry has fewer mathematical formulas but more reactions and processes to remember. Extended students must master mole calculations, which link many topics. The question papers give you the Periodic Table (with relative atomic masses) and the molar gas volume, but you must know how to use them.
Formulas marked Supp are Supplement-only. Use our IGCSE Chemistry flashcards to review key concepts, or practice with topic quizzes.
Mole Calculations
- n = m / Mr Supp
- n = V / 24 (gas at r.t.p., dm³) Supp
- n = c × V (solutions) Supp
- c = n / V (concentration) Supp
Yield & Purity
- % yield = (actual/theoretical) × 100 Supp
- % purity = (pure/total) × 100 Supp
Energy & Analysis
- ΔH = Σ(bonds broken) - Σ(bonds made) Supp
- Rf = distance (substance) / distance (solvent) Supp
Key Ionic Equations
- H⁺ + OH⁻ → H₂O (neutralisation)
- CO₃²⁻ + 2H⁺ → H₂O + CO₂ (carbonates + acid)
Study Tip: Mole Calculations
The mole concept connects mass, gas volume and concentration. Learn each relationship and rearrange it: n = m / Mr (so m = n × Mr), n = V / 24 for a gas in dm³ at r.t.p. (so V = n × 24), and n = c × V for a solution with V in dm³ (so c = n / V). If you use formula triangles, the quantity that equals the other two multiplied together goes at the top: mass in the mass triangle, moles in the concentration triangle. Practice with past paper questions until it becomes automatic.
Recommended Study Approach
Master the Fundamentals First
States of matter, atomic structure, and bonding underpin everything else. Get these solid before moving on.
Learn Organic Chemistry Systematically
It's 20% of the learning objectives. Learn the homologous series in order: alkanes → alkenes → alcohols → carboxylic acids → polymers.
Practice Mole Calculations (Extended)
If you're taking Extended, mole calculations come up across many topics. Practice until they're automatic.
Know Your Practical Techniques
Your practical paper (Paper 5 or 6) tests experimental skills. Know separation methods, titrations, and chemical tests thoroughly.
Use Past Papers Strategically
Practice with IGCSE Chemistry past papers to identify weak areas, then target those topics.
Key Takeaways
- 2026–2028 has no content changes - the same objectives as 2023–2025
- 252 total objectives - 154 Core, 98 Supplement-only
- Organic chemistry is king - 20% of the learning objectives, master it
- Know your tier - Core caps at grade C; Extended required for A*-B
- Mole calculations are crucial for Extended students
- Practical skills matter - your practical paper (5 or 6) tests experimental skills
Frequently Asked Questions
Is the 2026–2028 IGCSE Chemistry syllabus different from 2023–2025?
No, not in content. Cambridge says there are no substantial changes that would affect teaching, and comparing the two line by line, every learning objective is the same and in the same Core or Supplement column. Only small wording and layout details changed. The papers, marks and timings are also the same.
Can I still use past papers and notes from 2023–2025?
Yes. Because the content is unchanged, past papers from 2023 onwards are the closest practice you can get. Papers from before 2023 were written for an earlier syllabus, so some questions cover content that has since changed; use them with more care. Browse IGCSE Chemistry past papers.
Do exam questions follow this topic distribution?
There's no guarantee. While topics with more objectives (like organic chemistry at 20%) tend to appear more frequently, Cambridge can emphasize any topic in a given year. One paper might be heavy on stoichiometry, another on acids and bases. The syllabus distribution is a rough guide, not a prediction. The safest strategy: know everything, but spend proportionally more time on larger topics. Check past papers to see how questions actually vary.
Is IGCSE Chemistry harder than Physics?
They're different. Chemistry has more content to memorize (reactions, tests, organic chemistry) while Physics is more calculation-heavy. Chemistry Extended requires mastering mole calculations which many students find challenging initially.
Do I need to memorize all the reactions?
Yes, for the key reactions specified in the syllabus. These include reactions of acids with metals/bases/carbonates, displacement reactions, and organic reactions like fermentation and polymerisation. Understanding why reactions happen helps retention.
How important is organic chemistry?
Very important - it's the largest single topic at 20% of objectives. Questions on alkanes, alkenes, alcohols, carboxylic acids and polymers come up often. Learn the functional groups and typical reactions systematically.
Related Syllabus Guides
IGCSE Physics (0625)
6 syllabus topics, with more calculations than Chemistry - master the equations.
IGCSE Biology (0610)
21 syllabus topics, from living organisms to biotechnology. Diagrams and explanations matter.
Official Resources
- Cambridge IGCSE Chemistry (0620) Syllabus
- Full Syllabus PDF (2026-2028), for exams in 2026, 2027 and 2028
- Previous syllabus PDF (2023-2025), for reference
This guide is based on the Cambridge IGCSE Chemistry (0620) syllabus for examination in 2026, 2027 and 2028 (version 2, August 2026), compared with the 2023–2025 syllabus. Updated October 2026. Always refer to the official Cambridge syllabus for the definitive version.