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Dec 2, 2025
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Master 8th Grade Physical Science: Comprehensive States of Matter Study Guide
Shylah Holland
@hylaholland_xtry
1 / 4
States of Matter
Matter is anything that takes up space. It exists in four main states: solid, liquid, gas, and plasma. Each state has unique characteristics that determine how it behaves.
The arrangement and movement of particles differ in each state. In solids, particles are arranged in neat rows, maintain their own shape, and move slowly with little jiggles. Liquids have sloppy rows of particles that flow past each other and take the shape of their container. Gases have no order with particles spread out all over the place and moving quickly. Plasma particles move extremely fast and are spaced out.
When matter changes from one state to another, we call it a phase change. Melting happens when a solid transforms into a liquid by absorbing heat. Freezing occurs when a liquid becomes a solid by releasing heat. Deposition is when a gas transforms directly into a solid, releasing heat in the process.
💡 You experience phase changes every day! When ice cream melts on a hot day, that's the melting process in action. When water freezes in the freezer, that's the freezing process.
You can visually identify states of matter by how they fill containers. Liquids take the shape of their container but have a defined surface, gases fill the entire container, and solids maintain their own shape regardless of the container.
Heat Transfer
Heat always moves from warmer objects to cooler ones. When condensation occurs, gas particles slow down and become more organized as they change to liquid state.
Thermal energy is transferred between objects because they have different temperatures. This energy transfer stops when both objects reach the same temperature, called equilibrium. For example, when chocolate is in your pocket, heat moves from your body to the chocolate through conduction (particles bumping into each other).
There are three main ways heat transfers:
- Conduction occurs when objects of different temperatures are in direct contact, like a metal spoon getting hot in boiling water
- Convection happens when warm gas or liquid particles rise while cooler particles sink, creating currents
- Radiation transfers heat through electromagnetic waves without needing physical contact
🔥 Think about cooking: the pan heats your food through conduction, boiling water creates convection currents, and your toaster oven uses radiation to make toast!
Real-life examples help us understand these concepts. When a hot frying pan is placed in lukewarm water, thermal energy decreases in the pan and increases in the water as heat transfers between them.
More on Heat Transfer
Heat transfer happens all around us in everyday situations. A lava lamp demonstrates convection as warm liquid rises and cool liquid sinks. Feeling warmth from a campfire is radiation at work, while a hot handle on a fire poker is conduction in action.
Kinetic energy is the energy of motion. Thermal energy refers to the total amount of kinetic energy that an object has. The faster particles move, the more thermal energy they have. This explains why hot objects have more thermal energy than cold ones.
Every substance has specific temperature points where phase changes occur. The freezing point is the temperature at which a liquid becomes a solid. The melting point is the temperature at which a solid becomes a liquid. For water, these both happen at 0°C (32°F).
🌡️ Phase change temperatures vary widely between substances! While water freezes at 0°C, iron doesn't melt until it reaches about 1,538°C!
You can identify heat transfer methods by looking at situations. Radiation happens when heat travels through space, like from the sun. Convection occurs in fluids like air and water. Conduction happens between objects in direct contact, like your hand on a cold window.
Heat Transfer Summary
All matter has heat, which is a form of energy caused by vibrating particles. The faster these particles vibrate, the warmer the object becomes. Since particles are always in motion, heat transfer happens continuously around us.
Heat always flows in one direction: from hot to cold. This transfer stops only when objects reach the same temperature, a state called equilibrium. The three key ways heat transfers are conduction, convection, and radiation.
Conduction occurs when solid objects come into direct contact with each other. Convection happens in fluid substances (liquids and gases) when warmer, less dense particles rise and cooler, more dense particles sink, creating convection currents. Radiation transfers heat through waves that can travel through space without needing a medium.
🔍 Heat transfer explains countless everyday phenomena! From why soup gets cooler when you blow on it (convection) to why metal playground equipment gets hot in the sun (radiation and conduction).
All objects both emit and absorb heat energy. The amount they emit or absorb depends on their temperature relative to surrounding objects, continuing the cycle of heat transfer that's constantly happening all around us.
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What is the Knowunity AI companion?
Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.
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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
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
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
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
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 app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
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
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
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
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
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 app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user
Master 8th Grade Physical Science: Comprehensive States of Matter Study Guide
Shylah Holland
@hylaholland_xtry
Matter is all around us in different forms! This study guide explores the states of matter, how particles behave in each state, and the ways heat moves from place to place. Understanding these concepts helps explain countless everyday phenomena, from... Show more
States of Matter
Matter is anything that takes up space. It exists in four main states: solid, liquid, gas, and plasma. Each state has unique characteristics that determine how it behaves.
The arrangement and movement of particles differ in each state. In solids, particles are arranged in neat rows, maintain their own shape, and move slowly with little jiggles. Liquids have sloppy rows of particles that flow past each other and take the shape of their container. Gases have no order with particles spread out all over the place and moving quickly. Plasma particles move extremely fast and are spaced out.
When matter changes from one state to another, we call it a phase change. Melting happens when a solid transforms into a liquid by absorbing heat. Freezing occurs when a liquid becomes a solid by releasing heat. Deposition is when a gas transforms directly into a solid, releasing heat in the process.
💡 You experience phase changes every day! When ice cream melts on a hot day, that's the melting process in action. When water freezes in the freezer, that's the freezing process.
You can visually identify states of matter by how they fill containers. Liquids take the shape of their container but have a defined surface, gases fill the entire container, and solids maintain their own shape regardless of the container.
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Heat Transfer
Heat always moves from warmer objects to cooler ones. When condensation occurs, gas particles slow down and become more organized as they change to liquid state.
Thermal energy is transferred between objects because they have different temperatures. This energy transfer stops when both objects reach the same temperature, called equilibrium. For example, when chocolate is in your pocket, heat moves from your body to the chocolate through conduction (particles bumping into each other).
There are three main ways heat transfers:
- Conduction occurs when objects of different temperatures are in direct contact, like a metal spoon getting hot in boiling water
- Convection happens when warm gas or liquid particles rise while cooler particles sink, creating currents
- Radiation transfers heat through electromagnetic waves without needing physical contact
🔥 Think about cooking: the pan heats your food through conduction, boiling water creates convection currents, and your toaster oven uses radiation to make toast!
Real-life examples help us understand these concepts. When a hot frying pan is placed in lukewarm water, thermal energy decreases in the pan and increases in the water as heat transfers between them.
Sign up to see the contentIt's free!
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More on Heat Transfer
Heat transfer happens all around us in everyday situations. A lava lamp demonstrates convection as warm liquid rises and cool liquid sinks. Feeling warmth from a campfire is radiation at work, while a hot handle on a fire poker is conduction in action.
Kinetic energy is the energy of motion. Thermal energy refers to the total amount of kinetic energy that an object has. The faster particles move, the more thermal energy they have. This explains why hot objects have more thermal energy than cold ones.
Every substance has specific temperature points where phase changes occur. The freezing point is the temperature at which a liquid becomes a solid. The melting point is the temperature at which a solid becomes a liquid. For water, these both happen at 0°C (32°F).
🌡️ Phase change temperatures vary widely between substances! While water freezes at 0°C, iron doesn't melt until it reaches about 1,538°C!
You can identify heat transfer methods by looking at situations. Radiation happens when heat travels through space, like from the sun. Convection occurs in fluids like air and water. Conduction happens between objects in direct contact, like your hand on a cold window.
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
Heat Transfer Summary
All matter has heat, which is a form of energy caused by vibrating particles. The faster these particles vibrate, the warmer the object becomes. Since particles are always in motion, heat transfer happens continuously around us.
Heat always flows in one direction: from hot to cold. This transfer stops only when objects reach the same temperature, a state called equilibrium. The three key ways heat transfers are conduction, convection, and radiation.
Conduction occurs when solid objects come into direct contact with each other. Convection happens in fluid substances (liquids and gases) when warmer, less dense particles rise and cooler, more dense particles sink, creating convection currents. Radiation transfers heat through waves that can travel through space without needing a medium.
🔍 Heat transfer explains countless everyday phenomena! From why soup gets cooler when you blow on it (convection) to why metal playground equipment gets hot in the sun (radiation and conduction).
All objects both emit and absorb heat energy. The amount they emit or absorb depends on their temperature relative to surrounding objects, continuing the cycle of heat transfer that's constantly happening all around us.
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.
Where can I download the Knowunity app?
You can download the app in the Google Play Store and in the 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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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
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
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
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
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 app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
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
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
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
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
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 app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user