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M
Mae Valeria
11/28/2025
Science
The Internal Structure of the Earth
91
•
Nov 28, 2025
•
Understanding Earth's Internal Structure: Simplified for Easy Learning
M
Mae Valeria
@m.val_
1 / 4
Earth's Core: The Hot Center
Deep beneath your feet lies Earth's core, the hottest and most extreme part of our planet. This innermost layer reaches temperatures of 4,000 to 5,000 degrees Celsius - that's almost as hot as the Sun's surface!
The core is about 2,300 km thick and is made mostly of iron and nickel. What's really cool is that it's divided into two parts with completely different properties.
The outer core is liquid metal that flows around like a super-hot soup. This flowing liquid metal is actually what creates Earth's magnetic field - the invisible shield that protects us from harmful space radiation.
The inner core, despite being even hotter, is actually solid! This happens because of pressure freezing - the incredible pressure down there squeezes the metal particles so tightly together that they can't move around as a liquid.
Quick Fact: The pressure in the inner core is about 3.6 million times stronger than the pressure at Earth's surface!
Earth's Crust: Where We Live
The crust is Earth's outermost layer and the only part we can actually see and touch. Think of it like the thin skin on an apple - it's incredibly thin compared to the rest of the planet, but it's where all life exists.
There are two main types of crust with very different characteristics. Continental crust is what forms our continents and is made mostly of granite rock. It's thicker but lighter and less dense.
Oceanic crust makes up the ocean floors and is much thinner but denser and heavier. It's mostly made of basalt rock, which is darker and heavier than granite.
Scientists use the term SIAL (Silicon, Aluminum) to describe the crust's composition. The key thing to remember is that denser rocks like basalt are heavier, while less dense rocks like granite are lighter.
Memory Tip: Think "Continental = Thick but light, Oceanic = Thin but heavy"
Earth's Mantle: The Thick Middle
The mantle is Earth's middle layer and by far the thickest part of our planet. At about 2,900 km thick, it makes up 85% of Earth's volume and 70% of its mass - basically, most of our planet is mantle!
This layer is made of hot, plastic-like rocks that can flow very slowly over time, kind of like thick honey. The mantle is also called SIMA because it's rich in Silicon, Oxygen, and Magnesium.
Understanding Earth's layers helps explain how plate tectonics work. The large slabs of rock that make up Earth's surface actually float and move on top of the flowing mantle below.
Scientists classify Earth's layers in two ways: compositional (based on what they're made of) and mechanical (based on how rigid or flexible they are). This is why you might see different layer names in different contexts.
Real-World Connection: The mantle's slow movement is what causes earthquakes and volcanic eruptions at the surface!
Mechanical Layers: How Earth Moves
Beyond just chemical composition, geologists also classify Earth by how its layers behave mechanically. The lithosphere combines the crust with the uppermost rigid mantle - this is the solid, rocky shell we live on.
Just below that sits the asthenosphere, a weaker, more flexible layer in the upper mantle. This is where the rock is hot enough to flow slowly, allowing the lithosphere above to move around like puzzle pieces.
The mesosphere (not to be confused with the atmospheric layer) is the stronger, more solid part of the mantle below the asthenosphere. Here, even though it's extremely hot, the increased pressure makes the rock more rigid.
This mechanical layering system explains how plate tectonics actually work. The rigid lithospheric plates can move because they're floating on the softer asthenosphere beneath them, creating the continental drift that shapes our planet's surface over millions of years.
Study Tip: Remember that mechanical layers focus on strength and movement, while compositional layers focus on what materials make up each part.
We thought you’d never ask...
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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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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
Understanding Earth's Internal Structure: Simplified for Easy Learning
M
Mae Valeria
@m.val_
Ever wondered what's actually inside our planet? Earth isn't just a solid ball of rock - it's made up of different layers with unique properties that affect everything from earthquakes to our planet's magnetic field.
Earth's Core: The Hot Center
Deep beneath your feet lies Earth's core, the hottest and most extreme part of our planet. This innermost layer reaches temperatures of 4,000 to 5,000 degrees Celsius - that's almost as hot as the Sun's surface!
The core is about 2,300 km thick and is made mostly of iron and nickel. What's really cool is that it's divided into two parts with completely different properties.
The outer core is liquid metal that flows around like a super-hot soup. This flowing liquid metal is actually what creates Earth's magnetic field - the invisible shield that protects us from harmful space radiation.
The inner core, despite being even hotter, is actually solid! This happens because of pressure freezing - the incredible pressure down there squeezes the metal particles so tightly together that they can't move around as a liquid.
Quick Fact: The pressure in the inner core is about 3.6 million times stronger than the pressure at Earth's surface!
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Earth's Crust: Where We Live
The crust is Earth's outermost layer and the only part we can actually see and touch. Think of it like the thin skin on an apple - it's incredibly thin compared to the rest of the planet, but it's where all life exists.
There are two main types of crust with very different characteristics. Continental crust is what forms our continents and is made mostly of granite rock. It's thicker but lighter and less dense.
Oceanic crust makes up the ocean floors and is much thinner but denser and heavier. It's mostly made of basalt rock, which is darker and heavier than granite.
Scientists use the term SIAL (Silicon, Aluminum) to describe the crust's composition. The key thing to remember is that denser rocks like basalt are heavier, while less dense rocks like granite are lighter.
Memory Tip: Think "Continental = Thick but light, Oceanic = Thin but heavy"
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Earth's Mantle: The Thick Middle
The mantle is Earth's middle layer and by far the thickest part of our planet. At about 2,900 km thick, it makes up 85% of Earth's volume and 70% of its mass - basically, most of our planet is mantle!
This layer is made of hot, plastic-like rocks that can flow very slowly over time, kind of like thick honey. The mantle is also called SIMA because it's rich in Silicon, Oxygen, and Magnesium.
Understanding Earth's layers helps explain how plate tectonics work. The large slabs of rock that make up Earth's surface actually float and move on top of the flowing mantle below.
Scientists classify Earth's layers in two ways: compositional (based on what they're made of) and mechanical (based on how rigid or flexible they are). This is why you might see different layer names in different contexts.
Real-World Connection: The mantle's slow movement is what causes earthquakes and volcanic eruptions at the surface!
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
Mechanical Layers: How Earth Moves
Beyond just chemical composition, geologists also classify Earth by how its layers behave mechanically. The lithosphere combines the crust with the uppermost rigid mantle - this is the solid, rocky shell we live on.
Just below that sits the asthenosphere, a weaker, more flexible layer in the upper mantle. This is where the rock is hot enough to flow slowly, allowing the lithosphere above to move around like puzzle pieces.
The mesosphere (not to be confused with the atmospheric layer) is the stronger, more solid part of the mantle below the asthenosphere. Here, even though it's extremely hot, the increased pressure makes the rock more rigid.
This mechanical layering system explains how plate tectonics actually work. The rigid lithospheric plates can move because they're floating on the softer asthenosphere beneath them, creating the continental drift that shapes our planet's surface over millions of years.
Study Tip: Remember that mechanical layers focus on strength and movement, while compositional layers focus on what materials make up each part.
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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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