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Britain & the wider world: 1745 -1901
1l the quest for political stability: germany, 1871-1991
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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
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2s the making of modern britain, 1951-2007
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Chemistry
30 Nov 2025
231
2 pages
Mayesha ☆ @mayeshatas07
Ever wondered how scientists figured out what atoms actually look like? The story of atomic discovery is like... Show more
The atom has come a long way since ancient Greek philosophers first imagined tiny, unbreakable balls making up everything. Back then, they thought all atoms were identical spheres that couldn't be split - which is where we get the word "atom" meaning "indivisible."
John Dalton changed the game in 1803 by suggesting that atoms of different elements had different sizes. This was revolutionary because it meant each element had its own unique type of atom.
The real breakthrough came when J.J. Thomson discovered the electron in 1897. Suddenly, atoms weren't just solid balls anymore - they had smaller particles inside them! Thomson's famous plum pudding model imagined atoms like a Christmas pudding, with positive "pudding" containing negative "plums" (electrons) scattered throughout.
Quick Tip Remember the timeline by thinking of it as scientists gradually "zooming in" - from whole atoms to finding particles inside them, then discovering the structure of those particles.
Ernest Rutherford completely revolutionised our understanding with his solar system model. Through his famous gold foil experiment, he proved that atoms have a tiny, dense, positively charged nucleus at the centre, with electrons orbiting around it like planets around the sun.
Niels Bohr refined this further by introducing the electron shell model in 1913. Instead of electrons flying around randomly, Bohr showed they occupy specific energy levels or "shells" around the nucleus - a bit like seats in a stadium with different tiers.
The final piece of the puzzle came when James Chadwick discovered the neutron in 1932. This completed our understanding of atomic structure a nucleus containing positively charged protons and neutral neutrons, surrounded by negatively charged electrons in shells.
Remember This Each discovery built on the previous one - scientists didn't start from scratch but improved existing models based on new evidence. This is exactly how real science works!
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.
2
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore 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 fundamental concepts of atomic structure, including atomic particles, subatomic particles, and the distinction between elements and compounds. This summary covers key theories from Dalton to Bohr, the discovery of protons, neutrons, and electrons, and methods for separating mixtures. Ideal for AQA Chemistry C1 revision.
ChemistryExplore 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.
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
Mayesha ☆
@mayeshatas07
Ever wondered how scientists figured out what atoms actually look like? The story of atomic discovery is like a detective story that took over 2,000 years to solve, with each scientist building on the previous person's work to reveal the... Show more
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
The atom has come a long way since ancient Greek philosophers first imagined tiny, unbreakable balls making up everything. Back then, they thought all atoms were identical spheres that couldn't be split - which is where we get the word "atom" meaning "indivisible."
John Dalton changed the game in 1803 by suggesting that atoms of different elements had different sizes. This was revolutionary because it meant each element had its own unique type of atom.
The real breakthrough came when J.J. Thomson discovered the electron in 1897. Suddenly, atoms weren't just solid balls anymore - they had smaller particles inside them! Thomson's famous plum pudding model imagined atoms like a Christmas pudding, with positive "pudding" containing negative "plums" (electrons) scattered throughout.
Quick Tip: Remember the timeline by thinking of it as scientists gradually "zooming in" - from whole atoms to finding particles inside them, then discovering the structure of those particles.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Ernest Rutherford completely revolutionised our understanding with his solar system model. Through his famous gold foil experiment, he proved that atoms have a tiny, dense, positively charged nucleus at the centre, with electrons orbiting around it like planets around the sun.
Niels Bohr refined this further by introducing the electron shell model in 1913. Instead of electrons flying around randomly, Bohr showed they occupy specific energy levels or "shells" around the nucleus - a bit like seats in a stadium with different tiers.
The final piece of the puzzle came when James Chadwick discovered the neutron in 1932. This completed our understanding of atomic structure: a nucleus containing positively charged protons and neutral neutrons, surrounded by negatively charged electrons in shells.
Remember This: Each discovery built on the previous one - scientists didn't start from scratch but improved existing models based on new evidence. This is exactly how real science works!
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.
2
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore 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 fundamental concepts of atomic structure, including atomic particles, subatomic particles, and the distinction between elements and compounds. This summary covers key theories from Dalton to Bohr, the discovery of protons, neutrons, and electrons, and methods for separating mixtures. Ideal for AQA Chemistry C1 revision.
ChemistryExplore 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.
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