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Zofia
30/11/2025
Chemistry
States of Matter
757
•
30 Nov 2025
•
Understanding the States of Matter for GCSE Chemistry
Zofia
@zofia_577
1 / 3
The Three States of Matter
Think about water - it can be ice, liquid water, or steam, but it's still the same substance! The difference lies in how the tiny particles inside are moving and arranged.
Solids are the most rigid state because their particles are packed tightly together and can barely move. This is why your desk doesn't suddenly change shape or flow like honey. You can't squash a solid either - there's simply no room for the particles to get any closer together.
When you heat a solid enough, melting occurs at a specific temperature called the melting point. The heat gives the particles more energy to move around, breaking free from their fixed positions. Each pure substance has its own unique melting point - that's how scientists can identify different materials.
Liquids are the middle ground - their particles can slide past each other, which is why water takes the shape of whatever container you pour it into. However, the particles are still close together, so you can't compress liquids much either.
Quick Tip: Remember that particles in solids vibrate in place, whilst liquid particles can move around each other but stay relatively close together.
From Liquids to Gases
When you boil water for tea, you're witnessing boiling in action. This happens when a liquid gets hot enough to form bubbles of gas throughout the entire liquid, not just at the surface. Like melting, each liquid has its own specific boiling point where this dramatic change occurs.
Gases are completely different from solids and liquids. Their particles zoom around freely in all directions, filling up whatever space is available. Unlike solids and liquids, you can actually compress gases because there's loads of empty space between the particles.
But liquids don't always need to reach boiling point to become gases. Evaporation happens at the surface of liquids when the most energetic particles escape into the air. This is why puddles disappear on warm days and why wet clothes dry on the washing line.
The opposite process is condensation - when gas particles lose energy and stick together to form liquid droplets. You see this every time your bathroom mirror steams up after a hot shower.
Real-World Connection: Evaporation happens faster with larger surface areas and higher temperatures - that's why you spread wet clothes out to dry them quicker!
The Unusual Process of Sublimation
Some substances can pull off a pretty cool trick called sublimation - they skip the liquid stage entirely and go straight from solid to gas. It's like a scientific magic show!
You might have seen this with dry ice (solid carbon dioxide), which creates that spooky fog effect at Halloween parties. Iodine crystals also sublime, turning directly into purple vapour when heated gently.
The reverse process exists too, called deposition or desublimation, where gases turn directly back into solids. This is much rarer but does happen in nature - think of frost forming on windows during cold winter mornings.
Understanding these state changes helps explain so many everyday phenomena, from why ice cubes shrink in the freezer (sublimation!) to how your breath becomes visible on cold days (condensation).
Science Fact: Sublimation is why mothballs gradually disappear over time - they're slowly turning from solid directly into gas particles that you can smell!
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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.
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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
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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
Understanding the States of Matter for GCSE Chemistry
Zofia
@zofia_577
Ever wondered why ice melts or why you can smell perfume across a room? It's all about states of matter - the three different forms that substances can exist in around us every day. Understanding how solids, liquids, and gases... Show more
The Three States of Matter
Think about water - it can be ice, liquid water, or steam, but it's still the same substance! The difference lies in how the tiny particles inside are moving and arranged.
Solids are the most rigid state because their particles are packed tightly together and can barely move. This is why your desk doesn't suddenly change shape or flow like honey. You can't squash a solid either - there's simply no room for the particles to get any closer together.
When you heat a solid enough, melting occurs at a specific temperature called the melting point. The heat gives the particles more energy to move around, breaking free from their fixed positions. Each pure substance has its own unique melting point - that's how scientists can identify different materials.
Liquids are the middle ground - their particles can slide past each other, which is why water takes the shape of whatever container you pour it into. However, the particles are still close together, so you can't compress liquids much either.
Quick Tip: Remember that particles in solids vibrate in place, whilst liquid particles can move around each other but stay relatively close together.
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From Liquids to Gases
When you boil water for tea, you're witnessing boiling in action. This happens when a liquid gets hot enough to form bubbles of gas throughout the entire liquid, not just at the surface. Like melting, each liquid has its own specific boiling point where this dramatic change occurs.
Gases are completely different from solids and liquids. Their particles zoom around freely in all directions, filling up whatever space is available. Unlike solids and liquids, you can actually compress gases because there's loads of empty space between the particles.
But liquids don't always need to reach boiling point to become gases. Evaporation happens at the surface of liquids when the most energetic particles escape into the air. This is why puddles disappear on warm days and why wet clothes dry on the washing line.
The opposite process is condensation - when gas particles lose energy and stick together to form liquid droplets. You see this every time your bathroom mirror steams up after a hot shower.
Real-World Connection: Evaporation happens faster with larger surface areas and higher temperatures - that's why you spread wet clothes out to dry them quicker!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
The Unusual Process of Sublimation
Some substances can pull off a pretty cool trick called sublimation - they skip the liquid stage entirely and go straight from solid to gas. It's like a scientific magic show!
You might have seen this with dry ice (solid carbon dioxide), which creates that spooky fog effect at Halloween parties. Iodine crystals also sublime, turning directly into purple vapour when heated gently.
The reverse process exists too, called deposition or desublimation, where gases turn directly back into solids. This is much rarer but does happen in nature - think of frost forming on windows during cold winter mornings.
Understanding these state changes helps explain so many everyday phenomena, from why ice cubes shrink in the freezer (sublimation!) to how your breath becomes visible on cold days (condensation).
Science Fact: Sublimation is why mothballs gradually disappear over time - they're slowly turning from solid directly into gas particles that you can smell!
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.
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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