Subjects
Maths
Chemistry
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Responding to change (a2 only)
Infection and response
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Organisms respond to changes in their internal and external environments (a-level only)
Biological molecules
Organisation
Substance exchange
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Genetic information & variation
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Britain & the wider world: 1745 -1901
1l the quest for political stability: germany, 1871-1991
The cold war
Inter-war germany
Medieval period: 1066 -1509
2d religious conflict and the church in england, c1529-c1570
2o democracy and nazism: germany, 1918-1945
1f industrialisation and the people: britain, c1783-1885
1c the tudors: england, 1485-1603
2m wars and welfare: britain in transition, 1906-1957
World war two & the holocaust
2n revolution and dictatorship: russia, 1917-1953
2s the making of modern britain, 1951-2007
World war one
Britain: 1509 -1745
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Chemistry
7 Dec 2025
497
1 page
lily garland @lilyjgarland2
Ever wondered what everything around you is actually made of? From your phone to the air you breathe,... Show more
Back in the day, Dalton had a simple idea - he thought atoms were like solid snooker balls that couldn't be broken down any further. This was a decent start, but scientists soon discovered he was missing some crucial pieces of the puzzle.
Thomson came along and found electrons - tiny particles with a negative charge and hardly any mass. He created the plum pudding model, imagining atoms as a positive sphere with electrons dotted throughout like raisins in a pudding. Since atoms have equal numbers of protons and electrons , they're electrically neutral overall.
Then Rutherford blew everyone's minds with his alpha scattering experiment. He fired positive particles at gold foil, expecting them to pass straight through. Instead, some bounced back! This proved that atoms have a tiny, dense nucleus at their centre containing all the positive charge and most of the mass.
Chadwick discovered neutrons , whilst Bohr worked out that electrons orbit the nucleus at fixed distances in shells. These discoveries gave us the modern atomic model we use today.
Quick Tip Remember that protons and neutrons live in the nucleus, while electrons zoom around in shells outside!
Elements are the simplest substances - they're made of just one type of atom, and every atom has the same number of protons. Think hydrogen, oxygen, or carbon. Compounds are completely different - they're made when different types of atoms chemically bond together, like water (H₂O).
Mixtures are much more relaxed affairs. They contain two or more elements or compounds that are just hanging out together, not chemically bonded. The brilliant thing about mixtures is that you can separate them using physical processes - no chemical reactions needed!
You've got loads of separation techniques to choose from. Filtration separates insoluble solids from liquids, crystallisation gets soluble solids out of solutions, and paper chromatography identifies different substances in a mixture. For liquids, simple distillation works when boiling points are very different, whilst fractional distillation handles liquids with similar boiling points.
Isotopes are atoms of the same element with different numbers of neutrons. The relative atomic mass is the average mass of all an element's atoms, calculated using the abundance and mass of each isotope (abundance₁ × mass₁) + (abundance₂ × mass₂) ÷ 100.
Real-World Connection These separation techniques are used everywhere - from purifying drinking water to making medicines and even in forensic science!
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.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
19
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the fundamentals of chemical bonding, including ionic, covalent, and metallic structures. This summary covers the properties of solids, liquids, and gases, the formation of compounds, and the significance of giant covalent structures and nanoparticles. Ideal for AQA GCSE Chemistry Higher students seeking to understand the intricacies of molecular interactions and material properties.
ChemistryExplore the key concepts of bonding and structure in chemistry, including ionic, covalent, and metallic bonding, as well as the properties of giant covalent structures and nanoparticles. This summary covers essential topics for GCSE students, focusing on particle theory, intermolecular forces, and the unique characteristics of various molecular structures. Ideal for active recall and exam preparation.
ChemistryExplore the evolution of atomic models from John Dalton's solid spheres to Rutherford's nuclear atom and Bohr's electron shells. This summary highlights key experiments and theories that shaped our understanding of atomic structure, making it essential for students studying chemistry and physics.
ChemistryExplore the fundamental concepts of particles and the three states of matter: solids, liquids, and gases. This summary covers the arrangement and movement of particles, the kinetic molecular theory, and phase changes. Ideal for Year 7 students preparing for exams.
ChemistryExplore the key milestones in the evolution of atomic theory, from Democritus's indivisible atoms to Bohr's electron shell model. This summary covers the contributions of Dalton, Thompson, Rutherford, and Bohr, detailing the progression of ideas about atomic structure and the nature of matter. Ideal for students studying chemistry and physics.
ChemistryExplore the fundamentals of chemical bonding, including ionic, covalent, and metallic bonds. Understand the properties of carbon allotropes like diamond, graphite, and graphene, as well as the characteristics of ionic compounds and metallic structures. This summary is ideal for GCSE Chemistry students preparing for exams.
ChemistryApp Store
Google 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 S
iOS 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 Klich
Android 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.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
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 S
iOS 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 Klich
Android 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.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
lily garland
@lilyjgarland2
Ever wondered what everything around you is actually made of? From your phone to the air you breathe, it's all built from tiny particles called atoms. Scientists have spent centuries figuring out what atoms look like and how they work,... Show more
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Back in the day, Dalton had a simple idea - he thought atoms were like solid snooker balls that couldn't be broken down any further. This was a decent start, but scientists soon discovered he was missing some crucial pieces of the puzzle.
Thomson came along and found electrons - tiny particles with a negative charge and hardly any mass. He created the plum pudding model, imagining atoms as a positive sphere with electrons dotted throughout like raisins in a pudding. Since atoms have equal numbers of protons and electrons , they're electrically neutral overall.
Then Rutherford blew everyone's minds with his alpha scattering experiment. He fired positive particles at gold foil, expecting them to pass straight through. Instead, some bounced back! This proved that atoms have a tiny, dense nucleus at their centre containing all the positive charge and most of the mass.
Chadwick discovered neutrons , whilst Bohr worked out that electrons orbit the nucleus at fixed distances in shells. These discoveries gave us the modern atomic model we use today.
Quick Tip: Remember that protons and neutrons live in the nucleus, while electrons zoom around in shells outside!
Elements are the simplest substances - they're made of just one type of atom, and every atom has the same number of protons. Think hydrogen, oxygen, or carbon. Compounds are completely different - they're made when different types of atoms chemically bond together, like water (H₂O).
Mixtures are much more relaxed affairs. They contain two or more elements or compounds that are just hanging out together, not chemically bonded. The brilliant thing about mixtures is that you can separate them using physical processes - no chemical reactions needed!
You've got loads of separation techniques to choose from. Filtration separates insoluble solids from liquids, crystallisation gets soluble solids out of solutions, and paper chromatography identifies different substances in a mixture. For liquids, simple distillation works when boiling points are very different, whilst fractional distillation handles liquids with similar boiling points.
Isotopes are atoms of the same element with different numbers of neutrons. The relative atomic mass is the average mass of all an element's atoms, calculated using the abundance and mass of each isotope: (abundance₁ × mass₁) + (abundance₂ × mass₂) ÷ 100.
Real-World Connection: These separation techniques are used everywhere - from purifying drinking water to making medicines and even in forensic science!
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.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
19
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the fundamentals of chemical bonding, including ionic, covalent, and metallic structures. This summary covers the properties of solids, liquids, and gases, the formation of compounds, and the significance of giant covalent structures and nanoparticles. Ideal for AQA GCSE Chemistry Higher students seeking to understand the intricacies of molecular interactions and material properties.
ChemistryExplore the key concepts of bonding and structure in chemistry, including ionic, covalent, and metallic bonding, as well as the properties of giant covalent structures and nanoparticles. This summary covers essential topics for GCSE students, focusing on particle theory, intermolecular forces, and the unique characteristics of various molecular structures. Ideal for active recall and exam preparation.
ChemistryExplore the evolution of atomic models from John Dalton's solid spheres to Rutherford's nuclear atom and Bohr's electron shells. This summary highlights key experiments and theories that shaped our understanding of atomic structure, making it essential for students studying chemistry and physics.
ChemistryExplore the fundamental concepts of particles and the three states of matter: solids, liquids, and gases. This summary covers the arrangement and movement of particles, the kinetic molecular theory, and phase changes. Ideal for Year 7 students preparing for exams.
ChemistryExplore the key milestones in the evolution of atomic theory, from Democritus's indivisible atoms to Bohr's electron shell model. This summary covers the contributions of Dalton, Thompson, Rutherford, and Bohr, detailing the progression of ideas about atomic structure and the nature of matter. Ideal for students studying chemistry and physics.
ChemistryExplore the fundamentals of chemical bonding, including ionic, covalent, and metallic bonds. Understand the properties of carbon allotropes like diamond, graphite, and graphene, as well as the characteristics of ionic compounds and metallic structures. This summary is ideal for GCSE Chemistry students preparing for exams.
ChemistryApp Store
Google 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 S
iOS 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 Klich
Android 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.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
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 S
iOS 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 Klich
Android 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.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Sociology