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12 Dec 2025
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Understanding the Particle Model of Matter: Key Concepts Explained
Makz ‼️
@3lite.makz
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Density and Particle Theory
Density is simply how much mass is packed into a given space - it's mass divided by volume . Think of it like comparing a sponge to a brick of the same size - the brick has much higher density because it contains more mass in the same volume.
The golden rule is simple: higher density objects sink, lower density objects float. This explains why oil floats on water and why helium balloons rise up to the ceiling.
For your practicals, measuring density depends on the object's shape. Irregular objects go straight into a measuring cylinder with water - the volume displaced equals the object's volume. Regular objects use a eureka can where you collect and measure the overflow water.
Gas pressure happens because particles constantly smash into container walls. Heat up a gas and those particles move faster with more energy, creating higher pressure - which is exactly why that balloon might pop in hot weather!
Quick Tip: Remember the density triangle - cover what you want to find, and the formula appears!
States of Matter and Energy Changes
The three states of matter behave completely differently because of how their particles are arranged and move. Solids have particles locked in fixed positions that just vibrate, liquids let particles slide past each other, and gases have particles zooming around freely with loads of space between them.
Internal energy is the total kinetic and potential energy of all particles in a substance. When you heat something, you're pumping energy into those particles - but here's the clever bit: during melting or boiling, temperature stays constant even though you're still adding heat.
This happens because the energy goes into breaking the forces holding particles together (increasing potential energy) rather than making them move faster (increasing kinetic energy). It's like using energy to break chains rather than making the prisoners run faster!
Specific heat capacity tells you how much energy you need to warm up 1kg of something by 1°C, whilst specific latent heat tells you the energy needed to completely change the state of 1kg of material.
Remember: During state changes, temperature stays constant - all that energy goes into breaking particle bonds!
Essential Formulas
These two formulas are your best mates for energy calculations, and they're easier than they look!
For latent heat: E = mL. This calculates the energy needed to change state - like melting ice or boiling water. Just multiply the mass by the specific latent heat value (which you'll usually be given in exams).
For specific heat capacity: ΔE = mcΔθ. This works out energy changes when temperature actually changes. The Δ symbols just mean "change in" - so it's change in energy equals mass × specific heat capacity × change in temperature.
The key difference? Use latent heat when stuff is melting, boiling, or freezing (temperature stays the same). Use specific heat capacity when things are warming up or cooling down (temperature actually changes).
These formulas pop up constantly in physics exams, so practise rearranging them to find different variables. Cover up what you want to find, and the rest shows you the calculation!
Exam Tip: Always check your units match the formula - convert grams to kilograms if needed!
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Samantha Klich
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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
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Best app on earth! no words because it’s too good
Thomas R
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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.
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: Key Concepts Explained
Makz ‼️
@3lite.makz
Ever wondered why ice floats in your drink or why a balloon pops when it gets too hot? It's all about how tiny particles behave! Understanding density, particle movement, and energy changes will help you explain loads of everyday phenomena... Show more
Density and Particle Theory
Density is simply how much mass is packed into a given space - it's mass divided by volume . Think of it like comparing a sponge to a brick of the same size - the brick has much higher density because it contains more mass in the same volume.
The golden rule is simple: higher density objects sink, lower density objects float. This explains why oil floats on water and why helium balloons rise up to the ceiling.
For your practicals, measuring density depends on the object's shape. Irregular objects go straight into a measuring cylinder with water - the volume displaced equals the object's volume. Regular objects use a eureka can where you collect and measure the overflow water.
Gas pressure happens because particles constantly smash into container walls. Heat up a gas and those particles move faster with more energy, creating higher pressure - which is exactly why that balloon might pop in hot weather!
Quick Tip: Remember the density triangle - cover what you want to find, and the formula appears!
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States of Matter and Energy Changes
The three states of matter behave completely differently because of how their particles are arranged and move. Solids have particles locked in fixed positions that just vibrate, liquids let particles slide past each other, and gases have particles zooming around freely with loads of space between them.
Internal energy is the total kinetic and potential energy of all particles in a substance. When you heat something, you're pumping energy into those particles - but here's the clever bit: during melting or boiling, temperature stays constant even though you're still adding heat.
This happens because the energy goes into breaking the forces holding particles together (increasing potential energy) rather than making them move faster (increasing kinetic energy). It's like using energy to break chains rather than making the prisoners run faster!
Specific heat capacity tells you how much energy you need to warm up 1kg of something by 1°C, whilst specific latent heat tells you the energy needed to completely change the state of 1kg of material.
Remember: During state changes, temperature stays constant - all that energy goes into breaking particle bonds!
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
Essential Formulas
These two formulas are your best mates for energy calculations, and they're easier than they look!
For latent heat: E = mL. This calculates the energy needed to change state - like melting ice or boiling water. Just multiply the mass by the specific latent heat value (which you'll usually be given in exams).
For specific heat capacity: ΔE = mcΔθ. This works out energy changes when temperature actually changes. The Δ symbols just mean "change in" - so it's change in energy equals mass × specific heat capacity × change in temperature.
The key difference? Use latent heat when stuff is melting, boiling, or freezing (temperature stays the same). Use specific heat capacity when things are warming up or cooling down (temperature actually changes).
These formulas pop up constantly in physics exams, so practise rearranging them to find different variables. Cover up what you want to find, and the rest shows you the calculation!
Exam Tip: Always check your units match the formula - convert grams to kilograms if needed!
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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Most popular content: Specific Heat Capacity
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 — 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