Cambridge IGCSE Chemistry: everything you need to know

Studying Cambridge IGCSE Chemistry? Here's a full breakdown of the exam, so you know exactly what to expect.

If your school follows the Cambridge International curriculum, whether that's an international school abroad or a UK independent school, you're working towards Cambridge's own IGCSE qualification, officially called Chemistry (0620). This guide walks you through how the papers are structured, what you'll be tested on, and how to prepare with confidence. Read on to find out more.

Key takeaways:

• Cambridge IGCSE Chemistry is graded A* to G, not the 9 to 1 scale used in the UK's domestic GCSE.
• You'll take papers from either the Core route (grades capped at C) or the Extended route (full A* to G range), plus a practical component.
• Your school decides which route and which practical option you take.

What's the format of the Cambridge IGCSE Chemistry exam?

Your school will choose whether you follow the Core or Extended route, plus one of two practical options.

If you're on the Core route, you'll sit:

• Paper 1: Multiple Choice. 45 minutes, worth 40 marks (30%).
  
  • 40 questions, each with four possible answers, covering the Core content only.
• Paper 3: Theory. 1 hour 15 minutes, worth 80 marks (50%).
  
  • A mix of short-answer and structured questions on the Core content. This route caps your grade at a C.

If you're on the Extended route, you'll sit:

• Paper 2: Multiple Choice. 45 minutes, worth 40 marks (30%).
  
  • 40 questions, each with four possible answers, covering the Core content plus the extra Supplement topics.
• Paper 4: Theory. 1 hour 15 minutes, worth 80 marks (50%).
  
  • A mix of short-answer and structured questions covering the Core content plus the Supplement topics. This route gives access to the full A* to G grade range.

Everyone also sits one of these two practical options, worth 20%:

• Paper 5: Practical Test. 1 hour 15 minutes, worth 40 marks.
  
  • A hands-on lab exam where you'll carry out experiments, take measurements, make observations and record your results.
• Paper 6: Alternative to Practical. 1 hour, worth 40 marks.
  
  • A written paper that tests the same skills without a lab, such as reading experimental data, planning a method, and evaluating results.

You'll be given a copy of the Periodic Table in all your written papers, along with any apparatus lists or notes you need for the practical questions.

Ask your teacher which route and practical option applies to you, as this affects how you should prepare.

Full details are in the official Cambridge IGCSE Chemistry specification.

What are the grade boundaries for Cambridge IGCSE Chemistry?

It's important to remember that the exact grade boundaries for your exams will change every year. Cambridge sets them after the exam has been sat, based on how difficult the papers were and how the whole cohort performed.

Your final grade combines several papers, and depends on whether you took Core or Extended, so there isn't one single number that applies to everyone. Cambridge publishes the exact thresholds for every paper after each series on its grade threshold pages.

Use previous thresholds as a general guide to what a strong answer looks like, not as a fixed target. Boundaries can move by several marks either way from one series to the next.

What are examiners looking for?

Cambridge marks your answers against three skills, called assessment objectives. Examiners want to see that you can:

• Show knowledge and understanding of chemical facts, concepts and processes, worth 50% of your final grade.
• Handle information and solve problems, applying what you know to new situations, worth 30%.
• Show experimental skills, including planning, carrying out and evaluating investigations, worth 20%.

This is exactly what Atom GCSE is designed to support. It tracks your practice against each of these three assessment objectives separately, so you can see exactly where you're hitting the marks examiners are looking for and where you still need to improve.

It then shapes what it gives you to practise next around those gaps, with instant, examiner-style feedback on every answer, so you always know precisely where you're losing marks and what to change next time.

Past papers and resources

Cambridge publishes past papers, mark schemes and examiner reports for Chemistry (0620) on its past papers page. These are the best way to see exactly how questions are worded and how marks are awarded.

Atom gives you unlimited practice papers and questions, including predicted papers that Atom's team of experts build by analysing exam trends and data for the year ahead. And the best part? You don't have to mark them yourself, Atom's instant feedback lets you know exactly how you've done.

Take a look at our guide on how to get the most out of GCSE past papers to make sure you're getting the most out of both.

How can I prepare for Cambridge IGCSE Chemistry?

Here are 5 top tips to help you get ready:

1. Learn the periodic table trends, not just the facts

The periodic table shows patterns, like how reactive elements become as you move down a group. Try to understand why these patterns happen, not just memorise them.

Our free periodic table is a great visual for this: look at how the electron shells change as you move down a group, and try explaining the pattern out loud.

Top tip: Pick one trend and explain it in a single simple sentence, using the word "electrons." If you can do that, you really understand it.

2. Practise balancing equations little and often

Being able to balance equations quickly makes a real difference in the exam, since so many questions rely on it. Try a few equations every week, rather than leaving it all until closer to the exam.

Top tip: Time yourself balancing five equations. Getting a bit faster each time means more time for trickier questions later on.

3. Practise questions about experiments, not just facts

Whether you sit the hands-on practical exam or the written version, you'll be asked about experiments: what happened, why, and how to improve them. Get comfortable with this by looking at past experiment questions regularly, not just reading through notes.

Top tip: If a question asks how to improve an experiment, always give one clear suggestion and explain why it would help.

4. Show your working on every calculation

Chemistry calculations, like moles or percentage yield, often need a few steps to get to the answer. Write out every step clearly, even if you think you could do it in your head, since marks are given for your method too.

Top tip: Always include the units in your final answer, since forgetting them is a really common way to lose an easy mark.

5. Get used to the exam itself, not just the content

Knowing your chemistry well matters, but it helps just as much to know what the exam feels like: how long you have, how questions are worded, and what a good answer looks like. Try to build a bit of practice under exam conditions into your revision regularly.

Top tip: Atom gives you practice questions and predicted papers in the same style as the real exam, with instant feedback so you always know what to work on next.

There you have it, everything you need to know about Cambridge IGCSE Chemistry, from how the papers are structured to what examiners are looking for and how to prepare with confidence.