Chemistry units & topics
Tap a unit to see its topics. Every topic has free notes, a diagram, quizzes and flashcards.
GCSE Chemistry revision spans the entire material world — from atomic structure and bonding to organic chemistry and chemical analysis. You'll need to understand why reactions happen, how to predict products, calculate masses, and interpret experimental data. It's one of the most interconnected GCSE subjects: understanding bonding helps you understand properties, which helps you understand reactions.
The GCSE Chemistry exam is split into two papers. Paper 1 covers atomic structure, bonding, quantitative chemistry, chemical changes, and energy changes. Paper 2 covers rates of reaction, organic chemistry, chemical analysis, the atmosphere, and using resources. Both papers test recall, application, and extended writing.
Tap a unit to see its topics. Every topic has free notes, a diagram, quizzes and flashcards.
A simple, proven loop that works for every topic on this page — and beats re-reading your notes every time.
GCSE Chemistry calculations follow patterns. Learn the formula triangles for moles, concentration, and rate. Practise converting units (g to kg, cm³ to dm³). Do 5 calculation questions every revision session — the exam will have 8-12 marks of pure calculation, and these are the most reliable marks to pick up.
Create a reference sheet of every type of reaction: acid + metal, acid + carbonate, acid + alkali, oxidation, reduction, displacement, decomposition. For each, know the word equation, balanced symbol equation, and an example. This single sheet covers a huge portion of the GCSE Chemistry specification.
Mark schemes show you exactly what examiners want. Read the mark scheme for a 6-mark question before attempting it — you'll learn the expected structure. Then try similar questions without the mark scheme. GCSE Chemistry mark schemes are very precise about wording, especially for definitions.
You won't repeat the practicals in the exam, but you'll answer questions about them. For each practical, write out: aim, equipment list, method (step-by-step), independent/dependent/control variables, how to make it a fair test, and how to improve accuracy. This covers the practical skills that account for around 15% of marks.
Wherever you are in your GCSEs, here's the best place to pick up Chemistry.
Just starting GCSE content? Begin with the first unit — it underpins almost everything else in the Chemistry course.
Start from the beginningWorking through the course? Follow the units in order and learn one new topic at a time, testing as you go.
Browse all unitsExams approaching? Focus on the high-frequency topics examiners ask most, and drill them with quizzes and past questions.
See top exam topicsGCSE Chemistry is assessed across 6 written papers.
36 topics · Chemistry Paper 1
26 topics · Chemistry Paper 2
19 topics · Chemistry Paper 1 (C1–C3)
17 topics · Chemistry Paper 2 (C4–C6)
31 topics · Chemistry Paper 1
31 topics · Chemistry Paper 2
PrepWise covers 62 GCSE Chemistry topics across AQA, Edexcel and OCR. Each topic includes revision notes, exam-style questions, and flashcards.
Yes. All 62 topics, 1,301+ exam-style questions, and 1,019 flashcards are free during alpha. No card required, no trial period.
PrepWise covers AQA, Edexcel and OCR for GCSE Chemistry. You can select your board during setup and the content, questions, and daily plan adapt to your specification.
The highest-frequency GCSE Chemistry topics are atomic structure and the periodic table, bonding (ionic, covalent, metallic), rates of reaction, energy changes, and chemical analysis (flame tests, chromatography). Organic chemistry and equilibrium are Paper 2 topics that regularly appear at higher tier.
For students and parents — from Year 10 through to exam day
GCSE Chemistry revision spans the entire material world — from atomic structure and bonding to organic chemistry and chemical analysis. You'll need to understand why reactions happen, how to predict products, calculate masses, and interpret experimental data. It's one of the most interconnected GCSE subjects: understanding bonding helps you understand properties, which helps you understand reactions.
The GCSE Chemistry exam is split into two papers. Paper 1 covers atomic structure, bonding, quantitative chemistry, chemical changes, and energy changes. Paper 2 covers rates of reaction, organic chemistry, chemical analysis, the atmosphere, and using resources. Both papers test recall, application, and extended writing.
Around 20% of GCSE Chemistry marks come from mathematical skills — more than Biology. You'll need to calculate relative formula mass, work out moles, balance equations, and interpret rate graphs. Students who practise the maths consistently outperform those who focus only on theory. Equation practice is non-negotiable for GCSE Chemistry revision.
The three main exam boards cover similar GCSE Chemistry content, but question styles and practical requirements differ. Check which board your school follows to focus your GCSE Chemistry revision on the right material.
Two papers, each 1 hour 45 minutes, 100 marks. AQA is the most common board for GCSE Chemistry. It has 8 required practicals that are directly examined. AQA questions often give unfamiliar contexts — you might be asked about an industrial process you haven't studied and need to apply your knowledge.
Two papers, each 1 hour 45 minutes, 100 marks. Edexcel leans heavier on calculations than AQA, especially around moles and concentration. Their core practicals are numbered and referenced in exam questions. Extended writing questions tend to focus on evaluation of methods or environmental impacts.
Two papers, each 1 hour 45 minutes, 90 marks. OCR groups topics differently — for example, rates and equilibrium sit together. Their PAG-based practical assessment means practical skills are tested through written exam questions. OCR often asks students to compare bonding types or evaluate competing methods.
A complete gcse chemistry revision plan from Year 10 through to the final exam — with advice for students and tips for parents at every stage.
Start GCSE Chemistry revision habits from the beginning. After each lesson, write out the key equations and definitions. Year 10 typically covers atomic structure, bonding, and quantitative chemistry — these are the foundations everything else builds on. If you don't understand ionic and covalent bonding by the end of Year 10, everything in Year 11 will be harder. Parents: check your child can balance simple equations and draw dot-and-cross diagrams. These are fundamental skills.
Year 11 brings the harder GCSE Chemistry topics: organic chemistry, rates, equilibrium, and chemical analysis. Keep reviewing Paper 1 material while learning Paper 2 content. Start building an equations sheet — you'll need to recall formulas for moles, concentration, and rate calculations. Do 10 minutes of equation balancing practice every day; it sounds boring but it's worth 5-10 marks across both papers.
Audit every topic on the GCSE Chemistry specification. Rate each one red/amber/green and spend 70% of your revision time on reds. Make sure you understand electrolysis, organic reactions, and equilibrium — these are the topics most students struggle with. Start doing past paper questions by topic, marking them yourself using the mark scheme. Learn what examiners actually want — it's often not what you'd expect.
Mock exams reveal exactly where your GCSE Chemistry revision gaps are. After mocks, go through every question you dropped marks on and categorise why: was it knowledge, calculation, or exam technique? If you lost marks on moles calculations, you need to practise the formula triangle until it's automatic. If you lost marks on 6-mark questions, practise structuring answers with a clear opening statement, evidence, and conclusion.
Do one full GCSE Chemistry past paper per week under timed conditions. Focus on the calculation questions — work out moles, mass, concentration, and atom economy until the methods are second nature. Review all required practicals: know the equipment, method, variables, and how to evaluate results. Practise writing balanced symbol equations including state symbols — markers are strict about this.
Final GCSE Chemistry revision should focus on active recall. Test yourself on key reactions (acids + metals, acids + carbonates, neutralisation), organic homologous series, and tests for ions and gases. Don't forget the atmospheric chemistry section — it's a small topic but frequently examined. Make sure you know flame test colours, gas tests (limewater, splint, litmus), and chromatography Rf calculations. These are reliable marks if you've practised them.
GCSE Chemistry calculations follow patterns. Learn the formula triangles for moles, concentration, and rate. Practise converting units (g to kg, cm³ to dm³). Do 5 calculation questions every revision session — the exam will have 8-12 marks of pure calculation, and these are the most reliable marks to pick up.
Create a reference sheet of every type of reaction: acid + metal, acid + carbonate, acid + alkali, oxidation, reduction, displacement, decomposition. For each, know the word equation, balanced symbol equation, and an example. This single sheet covers a huge portion of the GCSE Chemistry specification.
Mark schemes show you exactly what examiners want. Read the mark scheme for a 6-mark question before attempting it — you'll learn the expected structure. Then try similar questions without the mark scheme. GCSE Chemistry mark schemes are very precise about wording, especially for definitions.
You won't repeat the practicals in the exam, but you'll answer questions about them. For each practical, write out: aim, equipment list, method (step-by-step), independent/dependent/control variables, how to make it a fair test, and how to improve accuracy. This covers the practical skills that account for around 15% of marks.
These come straight from examiner reports — the mistakes that cost students marks every year.
Writing 'atoms share electrons' for ionic bonding — ionic bonding involves electron TRANSFER. Sharing is covalent.
Forgetting state symbols in equations. Markers specifically look for (s), (l), (g), and (aq) in GCSE Chemistry papers.
Confusing exothermic and endothermic — exothermic releases energy (temperature rises), endothermic absorbs energy (temperature falls).
In electrolysis, mixing up what happens at the anode vs cathode. Remember OILRIG: Oxidation Is Loss (anode), Reduction Is Gain (cathode).
Leaving calculation answers without units or to the wrong number of significant figures.
As parents of GCSE students ourselves, we know how hard it is to support revision without being overbearing. Here's what actually helps with gcse chemistry revision at home.
GCSE Chemistry is the science subject where regular practice matters most. Even 15 minutes of equation balancing or calculation practice daily makes a measurable difference over a term.
Ask your child to explain bonding to you using real objects — salt for ionic, water for covalent. If they can't explain why table salt dissolves in water but diamond doesn't, they have a bonding gap to fill.
If your child finds Chemistry the hardest of the three sciences, they're not alone — it's consistently the lowest-scoring GCSE science nationally. The key is not to give up on the calculation topics, which is where most marks are lost.
Check that your child has a complete set of equations and definitions. Many schools provide a revision booklet — if not, the exam board specification lists every required equation and definition for free.
62 topics, all aligned to your exam board — learn, quiz and test your way through them.
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