This GCSE Chemistry cheat sheet covers the essential concepts you'll... Show more
Chemistry4,394 views·Updated May 31, 2026·2 pagesAQA GCSE Chemistry: Must-Know Cheat Sheet for Paper 1 Higher
Rebecca Thenderton@rebecca_mvvh
1
of 2
Chemical Changes and Energy
Acids and bases are everywhere in chemistry, and understanding them is crucial for your exams. Acids have a low pH because they produce H⁺ ions, while bases neutralise acids with their OH⁻ ions. The key equation to remember is: acid + base → salt + water.
When it comes to strong vs weak acids, don't confuse strength with concentration. Strong acids like hydrochloric acid (HCl) completely break apart in water, whilst weak acids like ethanoic acid only partially split up. This affects how they react, not how much acid you've got.
Electrolysis might seem tricky, but remember PANIC - Positive Anode Negative Is Cathode. Metals form positive ions and head to the negative cathode, while non-metals form negative ions and go to the positive anode. You'll need this for describing what happens during electrolysis.
Quick Tip: For electrolysis questions, always mention the ion, its charge, electrons gained/lost, and the element formed!
Energy changes split into two camps: exothermic reactions (release energy, temperature goes up) like combustion, and endothermic reactions (absorb energy, temperature drops) like dissolving. Fuel cells are brilliant because they only produce water as waste, though storing hydrogen is still a challenge.
2
of 2
Atomic Structure and Bonding
Your periodic table knowledge starts with knowing that proton number determines the element - this never changes. Isotopes are the same element with different neutrons, which is why relative atomic mass calculations pop up in exams using abundance percentages.
Mendeleev was clever enough to leave gaps in his periodic table and predict missing elements, unlike earlier scientists who just arranged by mass. Today's version uses atomic number, where group number equals outer shell electrons and period equals number of shells.
Chemical bonding comes in three flavours: ionic , covalent , and metallic (delocalised electrons). Each creates different properties - giant structures have high melting points, while simple covalent molecules have low melting points.
Memory Aid: Remember "I Have No Clever Or Brainy Friends" for diatomic elements (I₂, H₂, N₂, Cl₂, O₂, Br₂, F₂)!
Quantitative chemistry calculations follow the same pattern: work out Mr, calculate moles of what you know, find the ratio, then calculate what you need. For concentration calculations, remember that 1000 cm³ = 1 dm³, and always show your working - you'll get marks even if the final answer isn't perfect.
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Chemistry4,394 views·Updated May 31, 2026·2 pagesAQA GCSE Chemistry: Must-Know Cheat Sheet for Paper 1 Higher
Rebecca Thenderton@rebecca_mvvh
This GCSE Chemistry cheat sheet covers the essential concepts you'll need for Paper 1, focusing on chemical changes, energy reactions, atomic structure, bonding, and quantitative chemistry. These topics form the foundation of chemistry and directly link to exam questions you'll... Show more
1
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Chemical Changes and Energy
Acids and bases are everywhere in chemistry, and understanding them is crucial for your exams. Acids have a low pH because they produce H⁺ ions, while bases neutralise acids with their OH⁻ ions. The key equation to remember is: acid + base → salt + water.
When it comes to strong vs weak acids, don't confuse strength with concentration. Strong acids like hydrochloric acid (HCl) completely break apart in water, whilst weak acids like ethanoic acid only partially split up. This affects how they react, not how much acid you've got.
Electrolysis might seem tricky, but remember PANIC - Positive Anode Negative Is Cathode. Metals form positive ions and head to the negative cathode, while non-metals form negative ions and go to the positive anode. You'll need this for describing what happens during electrolysis.
Quick Tip: For electrolysis questions, always mention the ion, its charge, electrons gained/lost, and the element formed!
Energy changes split into two camps: exothermic reactions (release energy, temperature goes up) like combustion, and endothermic reactions (absorb energy, temperature drops) like dissolving. Fuel cells are brilliant because they only produce water as waste, though storing hydrogen is still a challenge.
2
of 2Sign up to see the content. It's free!
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Atomic Structure and Bonding
Your periodic table knowledge starts with knowing that proton number determines the element - this never changes. Isotopes are the same element with different neutrons, which is why relative atomic mass calculations pop up in exams using abundance percentages.
Mendeleev was clever enough to leave gaps in his periodic table and predict missing elements, unlike earlier scientists who just arranged by mass. Today's version uses atomic number, where group number equals outer shell electrons and period equals number of shells.
Chemical bonding comes in three flavours: ionic , covalent , and metallic (delocalised electrons). Each creates different properties - giant structures have high melting points, while simple covalent molecules have low melting points.
Memory Aid: Remember "I Have No Clever Or Brainy Friends" for diatomic elements (I₂, H₂, N₂, Cl₂, O₂, Br₂, F₂)!
Quantitative chemistry calculations follow the same pattern: work out Mr, calculate moles of what you know, find the ratio, then calculate what you need. For concentration calculations, remember that 1000 cm³ = 1 dm³, and always show your working - you'll get marks even if the final answer isn't perfect.
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Most popular content: Energy Profile
1Most popular content in Chemistry
9Most popular content
9Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.6/5App Store
4.7/5Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan SiOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha KlichAndroid user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
AnnaiOS user