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3 Jan 2026
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Understanding the Particle Model of Matter: Heat and Energy Explained
M
Mia Turner
@iaurner_yadrk5db0uaw
1 / 4
Particle Model of Matter
Think of everything around you as being made of tiny invisible particles - that's exactly what the particle model shows us! This model explains why solids, liquids, and gases behave so differently.
Density is basically how tightly packed these particles are. It's calculated as mass divided by volume , measured in kg/m³. Imagine a crowded lift versus an empty playground - that's the difference between high and low density.
In solids, particles are packed closely together with strong forces holding them in a regular structure. They can't move around or flow, and you can't compress them. Liquids have particles that are close but with gaps, weaker forces, and can flow but still can't be compressed. Gases have particles far apart with weak forces, constant random motion, and can be compressed and expand to fill any container.
Quick Tip: Remember the crowd analogy - solids are like a packed concert, liquids like people walking through a shopping centre, and gases like people scattered across a massive field!
Internal Energy and State Changes
Your hot cup of tea has internal energy - this is all the energy stored by particles in their movement (kinetic) and position (potential). When you heat something, you're adding to this internal energy store.
Here's what's brilliant: when substances change state, the temperature stays constant even though you're adding energy! During melting, boiling, or freezing, all that energy goes into breaking or forming bonds between particles instead of making them move faster.
Internal energy increases when solids melt to liquids, liquids boil to gases, or solids sublimate directly to gases. It decreases during freezing, condensation, and deposition. Think of it like this - particles need energy to break free from each other, just like you need energy to break free from a group hug!
The temperature change depends on the mass of substance, type of material, and how much energy you put in. More mass or less energy input means smaller temperature changes.
Remember: During state changes, temperature stays constant while internal energy changes - it's like all the energy is busy breaking particle bonds rather than heating up!
Specific Heat Capacity and Latent Heat
Specific heat capacity (SHC) tells you how much energy you need to heat up 1kg of a material by 1°C. Different materials need different amounts - water needs loads of energy, which is why it takes ages to boil a kettle!
The equation is: Change in energy = mass × specific heat capacity × temperature change. This explains why a small amount of hot oil can burn you badly (low SHC means it releases lots of energy quickly), whilst a large amount of warm water might not.
Specific latent heat (SLH) is the energy needed to change state without changing temperature. There are two types: latent heat of fusion (solid ↔ liquid) and latent heat of vaporisation (liquid ↔ gas). The equation is: Q = mL.
Vaporisation always needs more energy than fusion - it takes much more energy to turn water into steam than to melt ice. That's why steam burns are so dangerous!
Real-world connection: This is why sweating cools you down - your body heat provides the latent heat of vaporisation to turn sweat into water vapour!
Gas Pressure and Volume Laws
Gas pressure comes from particles constantly hitting container walls - more hits or harder hits means higher pressure. Atmospheric pressure is about 101,000 Pa (or 101 kPa), which is like having a 10kg weight pressing on every square centimetre!
Boyle's Law shows that pressure and volume are inversely proportional when temperature stays constant. Double the pressure, and volume halves: P₁V₁ = P₂V₂. Imagine squashing a balloon - as you reduce its volume, the pressure inside increases.
Pressure Law tells us that pressure is directly proportional to absolute temperature: P₁/T₁ = P₂/T₂. Remember to always use Kelvin for temperature calculations! To convert: Kelvin = Celsius + 273.
These laws work because they're all about particle movement. Higher temperature means faster-moving particles hitting walls harder. Less volume means particles hit walls more often. It's like having more energetic people in a smaller room!
Exam tip: Always convert Celsius to Kelvin for gas law calculations - just add 273 to your Celsius temperature!
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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
Understanding the Particle Model of Matter: Heat and Energy Explained
M
Mia Turner
@iaurner_yadrk5db0uaw
Ever wondered what makes ice different from water vapour, or why a balloon shrinks in the cold? The particle model of matter explains how tiny particles behave to create the three states of matter we see around us, and how... Show more
Particle Model of Matter
Think of everything around you as being made of tiny invisible particles - that's exactly what the particle model shows us! This model explains why solids, liquids, and gases behave so differently.
Density is basically how tightly packed these particles are. It's calculated as mass divided by volume , measured in kg/m³. Imagine a crowded lift versus an empty playground - that's the difference between high and low density.
In solids, particles are packed closely together with strong forces holding them in a regular structure. They can't move around or flow, and you can't compress them. Liquids have particles that are close but with gaps, weaker forces, and can flow but still can't be compressed. Gases have particles far apart with weak forces, constant random motion, and can be compressed and expand to fill any container.
Quick Tip: Remember the crowd analogy - solids are like a packed concert, liquids like people walking through a shopping centre, and gases like people scattered across a massive field!
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Internal Energy and State Changes
Your hot cup of tea has internal energy - this is all the energy stored by particles in their movement (kinetic) and position (potential). When you heat something, you're adding to this internal energy store.
Here's what's brilliant: when substances change state, the temperature stays constant even though you're adding energy! During melting, boiling, or freezing, all that energy goes into breaking or forming bonds between particles instead of making them move faster.
Internal energy increases when solids melt to liquids, liquids boil to gases, or solids sublimate directly to gases. It decreases during freezing, condensation, and deposition. Think of it like this - particles need energy to break free from each other, just like you need energy to break free from a group hug!
The temperature change depends on the mass of substance, type of material, and how much energy you put in. More mass or less energy input means smaller temperature changes.
Remember: During state changes, temperature stays constant while internal energy changes - it's like all the energy is busy breaking particle bonds rather than heating up!
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
Specific Heat Capacity and Latent Heat
Specific heat capacity (SHC) tells you how much energy you need to heat up 1kg of a material by 1°C. Different materials need different amounts - water needs loads of energy, which is why it takes ages to boil a kettle!
The equation is: Change in energy = mass × specific heat capacity × temperature change. This explains why a small amount of hot oil can burn you badly (low SHC means it releases lots of energy quickly), whilst a large amount of warm water might not.
Specific latent heat (SLH) is the energy needed to change state without changing temperature. There are two types: latent heat of fusion (solid ↔ liquid) and latent heat of vaporisation (liquid ↔ gas). The equation is: Q = mL.
Vaporisation always needs more energy than fusion - it takes much more energy to turn water into steam than to melt ice. That's why steam burns are so dangerous!
Real-world connection: This is why sweating cools you down - your body heat provides the latent heat of vaporisation to turn sweat into water vapour!
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
Gas Pressure and Volume Laws
Gas pressure comes from particles constantly hitting container walls - more hits or harder hits means higher pressure. Atmospheric pressure is about 101,000 Pa (or 101 kPa), which is like having a 10kg weight pressing on every square centimetre!
Boyle's Law shows that pressure and volume are inversely proportional when temperature stays constant. Double the pressure, and volume halves: P₁V₁ = P₂V₂. Imagine squashing a balloon - as you reduce its volume, the pressure inside increases.
Pressure Law tells us that pressure is directly proportional to absolute temperature: P₁/T₁ = P₂/T₂. Remember to always use Kelvin for temperature calculations! To convert: Kelvin = Celsius + 273.
These laws work because they're all about particle movement. Higher temperature means faster-moving particles hitting walls harder. Less volume means particles hit walls more often. It's like having more energetic people in a smaller room!
Exam tip: Always convert Celsius to Kelvin for gas law calculations - just add 273 to your Celsius temperature!
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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Students love us — 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 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