Matter exists in three states - solid, liquid, and gas... Show more
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0
grace ๐ซ
05/12/2025
Physics
physics paper one notes
50
โข
5 Dec 2025
โข
GCSE Physics Paper 1 and 3 Notes
grace ๐ซ
@ramagcrkse
1 / 7
The Three States of Matter
Ever wondered why ice keeps its shape but steam fills an entire room? It's all about how particles are arranged and how strongly they attract each other.
In solids, particles are packed tightly together with strong forces holding them in fixed positions. This is why your phone doesn't suddenly change shape! When you heat a solid, particles vibrate more until they reach the melting point - then they break free and become a liquid.
Liquids have weaker forces between particles, so they can move around whilst staying close together. Heat them up enough and you reach the boiling point, where particles gain enough energy to escape completely and become a gas. Gas particles zoom about freely with very weak attractions, which is why they fill any container you put them in.
Quick Tip: Remember the pattern - heating gives particles more energy to break bonds, cooling takes energy away so bonds can form again.
Density and How to Calculate It
Here's something that might surprise you - when ice melts into water, the mass stays exactly the same, but the density changes dramatically. Solids have the highest density, then liquids, then gases have the lowest.
Density tells you how much stuff is packed into a given space, calculated using: density = mass รท volume. You'll see this written as ฯ = m/V in exams, where ฯ (rho) is density.
For experiments, measuring density is straightforward but requires different techniques. Regular solids? Measure length, width, and height, then multiply for volume. Irregular shapes need a eureka can - the displaced water equals the object's volume. For liquids, zero your balance with an empty beaker, pour in the liquid, then divide the mass by the volume.
Exam Hack: Remember that 1 g/cmยณ = 1000 kg/mยณ - you'll often need to convert between these units!
Specific Latent Heat Explained
You might think that heating something always makes it hotter, but that's not quite true! When substances change state (like ice melting), temperature actually stays constant even though you're adding energy.
This happens because the energy you're providing isn't increasing the particles' movement - instead, it's breaking the bonds holding particles together. That's why ice sits at exactly 0ยฐC whilst melting, even though you're pumping heat into it.
The same thing happens in reverse when cooling. As a gas condenses into liquid, new bonds form and release energy, which counteracts the cooling effect. This is why steam at 100ยฐC is far more dangerous than boiling water at 100ยฐC - that steam contains loads of latent heat ready to be released.
Real-world Connection: This is exactly how your freezer works - it removes latent heat to change water vapour back into ice!
Calculating Energy Changes
Specific latent heat is the energy needed to change exactly 1kg of a substance from one state to another without changing temperature. Think of it as the "entry fee" particles pay to change state.
There are two types you need to know: specific latent heat of fusion (solid โ liquid) is about 334,000 J/kg for water, whilst specific latent heat of vaporisation (liquid โ gas) is much higher at 2,260,000 J/kg. Vaporisation needs more energy because you're completely separating particles.
The calculation is beautifully simple: Energy = mass ร specific latent heat, or E = mL. Whether energy is required (heating) or released (cooling) depends on the direction of change.
Memory Trick: Vaporisation has a much higher value because gas particles need loads more energy to break completely free!
Gas Pressure Factors
Gas pressure happens when particles smash into container walls - more collisions or harder impacts mean higher pressure. It's like being in a busy corridor where everyone's rushing about!
Temperature is a major factor: heat up a gas and particles move faster, creating more frequent and forceful collisions. This is why aerosol cans explode if overheated - the pressure becomes too much for the container.
Concentration matters too - pack more particles into the same space and you get more collisions per second. Finally, volume plays a crucial role: squeeze gas into a smaller space and particles hit the walls more often, dramatically increasing pressure.
Safety Note: This explains why you should never heat pressurised containers - temperature and pressure are directly linked!
Pressure-Volume Relationships and Energy Stores
Here's a fundamental rule: pressure and volume are inversely related. Double the pressure and you'll halve the volume, following the equation PโVโ = PโVโ. This relationship is essential for understanding everything from bicycle pumps to car engines.
Energy exists in multiple stores: thermal, kinetic, gravitational potential, elastic potential, chemical, magnetic, electrostatic, and nuclear. The golden rule is that energy is never created or destroyed - it just transfers between stores.
Work done equals energy transfer, whether that's mechanical (applying force), electrical (overcoming resistance), heating, or radiation. A coal fire demonstrates this perfectly: chemical energy in coal transfers by heating to thermal energy, then radiates out to warm your surroundings.
Key Concept: Every energy transfer follows the same rule - energy moves from one store to another, but the total amount never changes!
Energy Transfer Examples
Car braking shows energy transfer in action beautifully. Your moving car has kinetic energy in its motion, but when you brake, this energy must go somewhere - it transfers to thermal energy in the brake pads and discs through friction.
This is why brakes get incredibly hot during heavy use and why racing cars sometimes have glowing brake discs! The energy hasn't disappeared; it's simply changed from the energy of motion into heat energy that gets released to the surroundings.
Understanding these transfers helps you predict what happens in countless real situations, from why your hands warm up when you rub them together to how regenerative braking in electric cars works.
Think About It: Every time you stop moving, that kinetic energy has to go somewhere - usually heat!
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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.
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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 itโs 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 didnโt even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as Iโm 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 ๐๐๐ฒ๐ค๐โจ๐๐ฎ
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 itโs 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 didnโt even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as Iโm 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 ๐๐๐ฒ๐ค๐โจ๐๐ฎ
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
GCSE Physics Paper 1 and 3 Notes
grace ๐ซ
@ramagcrkse
Matter exists in three states - solid, liquid, and gas - and understanding how particles behave in each state is crucial for grasping physics and chemistry concepts. This particle model explains everything from why ice melts to how pressure cookers... Show more
The Three States of Matter
Ever wondered why ice keeps its shape but steam fills an entire room? It's all about how particles are arranged and how strongly they attract each other.
In solids, particles are packed tightly together with strong forces holding them in fixed positions. This is why your phone doesn't suddenly change shape! When you heat a solid, particles vibrate more until they reach the melting point - then they break free and become a liquid.
Liquids have weaker forces between particles, so they can move around whilst staying close together. Heat them up enough and you reach the boiling point, where particles gain enough energy to escape completely and become a gas. Gas particles zoom about freely with very weak attractions, which is why they fill any container you put them in.
Quick Tip: Remember the pattern - heating gives particles more energy to break bonds, cooling takes energy away so bonds can form again.
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Density and How to Calculate It
Here's something that might surprise you - when ice melts into water, the mass stays exactly the same, but the density changes dramatically. Solids have the highest density, then liquids, then gases have the lowest.
Density tells you how much stuff is packed into a given space, calculated using: density = mass รท volume. You'll see this written as ฯ = m/V in exams, where ฯ (rho) is density.
For experiments, measuring density is straightforward but requires different techniques. Regular solids? Measure length, width, and height, then multiply for volume. Irregular shapes need a eureka can - the displaced water equals the object's volume. For liquids, zero your balance with an empty beaker, pour in the liquid, then divide the mass by the volume.
Exam Hack: Remember that 1 g/cmยณ = 1000 kg/mยณ - you'll often need to convert between these units!
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Improve your grades
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Specific Latent Heat Explained
You might think that heating something always makes it hotter, but that's not quite true! When substances change state (like ice melting), temperature actually stays constant even though you're adding energy.
This happens because the energy you're providing isn't increasing the particles' movement - instead, it's breaking the bonds holding particles together. That's why ice sits at exactly 0ยฐC whilst melting, even though you're pumping heat into it.
The same thing happens in reverse when cooling. As a gas condenses into liquid, new bonds form and release energy, which counteracts the cooling effect. This is why steam at 100ยฐC is far more dangerous than boiling water at 100ยฐC - that steam contains loads of latent heat ready to be released.
Real-world Connection: This is exactly how your freezer works - it removes latent heat to change water vapour back into ice!
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Calculating Energy Changes
Specific latent heat is the energy needed to change exactly 1kg of a substance from one state to another without changing temperature. Think of it as the "entry fee" particles pay to change state.
There are two types you need to know: specific latent heat of fusion (solid โ liquid) is about 334,000 J/kg for water, whilst specific latent heat of vaporisation (liquid โ gas) is much higher at 2,260,000 J/kg. Vaporisation needs more energy because you're completely separating particles.
The calculation is beautifully simple: Energy = mass ร specific latent heat, or E = mL. Whether energy is required (heating) or released (cooling) depends on the direction of change.
Memory Trick: Vaporisation has a much higher value because gas particles need loads more energy to break completely free!
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Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Gas Pressure Factors
Gas pressure happens when particles smash into container walls - more collisions or harder impacts mean higher pressure. It's like being in a busy corridor where everyone's rushing about!
Temperature is a major factor: heat up a gas and particles move faster, creating more frequent and forceful collisions. This is why aerosol cans explode if overheated - the pressure becomes too much for the container.
Concentration matters too - pack more particles into the same space and you get more collisions per second. Finally, volume plays a crucial role: squeeze gas into a smaller space and particles hit the walls more often, dramatically increasing pressure.
Safety Note: This explains why you should never heat pressurised containers - temperature and pressure are directly linked!
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Pressure-Volume Relationships and Energy Stores
Here's a fundamental rule: pressure and volume are inversely related. Double the pressure and you'll halve the volume, following the equation PโVโ = PโVโ. This relationship is essential for understanding everything from bicycle pumps to car engines.
Energy exists in multiple stores: thermal, kinetic, gravitational potential, elastic potential, chemical, magnetic, electrostatic, and nuclear. The golden rule is that energy is never created or destroyed - it just transfers between stores.
Work done equals energy transfer, whether that's mechanical (applying force), electrical (overcoming resistance), heating, or radiation. A coal fire demonstrates this perfectly: chemical energy in coal transfers by heating to thermal energy, then radiates out to warm your surroundings.
Key Concept: Every energy transfer follows the same rule - energy moves from one store to another, but the total amount never changes!
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By signing up you accept Terms of Service and Privacy Policy
Energy Transfer Examples
Car braking shows energy transfer in action beautifully. Your moving car has kinetic energy in its motion, but when you brake, this energy must go somewhere - it transfers to thermal energy in the brake pads and discs through friction.
This is why brakes get incredibly hot during heavy use and why racing cars sometimes have glowing brake discs! The energy hasn't disappeared; it's simply changed from the energy of motion into heat energy that gets released to the surroundings.
Understanding these transfers helps you predict what happens in countless real situations, from why your hands warm up when you rub them together to how regenerative braking in electric cars works.
Think About It: Every time you stop moving, that kinetic energy has to go somewhere - usually heat!
We thought youโd 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 โ all at your fingertips.
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Most popular content: First Law of Thermodynamics
Most popular content in Physics
Most popular content
English - inspector calls quotes and analysis
Quotes from every main character
English Literature10
Can't find what you're looking for? Explore other subjects.
Students love us โ and so will you.
4.9/5
App Store
4.8/5
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 itโs 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 didnโt even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as Iโm 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 ๐๐๐ฒ๐ค๐โจ๐๐ฎ
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 itโs 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 didnโt even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as Iโm 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 ๐๐๐ฒ๐ค๐โจ๐๐ฎ
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