Subjects
Biology
Chemistry
AP Chemistry
English
AP English Literature
Chemistry
Dec 2, 2025
268
7 pages
Annie Owen-Stiff @annieowenstiff_dvtk
The evolution of the Earth's atmosphere over billion yearstransformed from a volcanic CO₂-rich environment to our current... Show more
The second phase of atmospheric evolution was marked by significant changes in the Earth's surface and composition. This period saw the formation of oceans and the beginning of carbon sequestration processes.
As the Earth cooled, the water vapor in the atmosphere began to condense, forming the planet's oceans. This process had a profound effect on the atmospheric composition, as large amounts of CO₂ were removed from the air by dissolving in the newly formed oceans. The dissolved CO₂ underwent a series of chemical reactions, forming carbon precipitates that settled on the seabed as sediments.
During this phase, the first green plants and algae evolved. These organisms played a crucial role in further reducing atmospheric CO₂ levels by absorbing it for photosynthesis. Some of the carbon absorbed by these early life forms eventually became fossil fuels after their death and burial.
Definition Carbon sequestration - The process of capturing and storing atmospheric carbon dioxide.
Example The formation of limestone deposits on the ocean floor is an example of natural carbon sequestration.
Greenhouse gases, primarily CO₂, methane, and water vapor, play a significant role in regulating Earth's temperature. These gases act as an insulating layer in the Earth's atmosphere, trapping heat and contributing to the greenhouse effect.
The impact of greenhouse gases on climate change is substantial. These gases don't absorb short-wavelength radiation but do absorb and re-radiate long-wavelength radiation in all directions, including back to Earth. This process, known as the greenhouse effect, warms the planet.
Human activities have significantly increased the concentration of greenhouse gases in the atmosphere, leading to accelerated climate change. Some key factors contributing to this increase include
Highlight The impact of greenhouse gases on climate change is evident in rising sea levels, changes in rainfall patterns, and increased frequency and severity of storms.
The third phase of atmospheric evolution saw a dramatic increase in oxygen levels, leading to the composition similar to what we have today.
About 200 million years ago, the Earth's atmosphere reached a composition similar to its current state. This transformation was primarily driven by the proliferation of plants and algae, which produced oxygen as a byproduct of photosynthesis.
The current atmosphere consists of approximately 80% nitrogen and 20% oxygen, with small amounts of other gases, including CO₂, noble gases, and water vapor.
Quote "200 million years ago atmosphere reached a composition similar to one it is today."
Carbon footprints are a measure of the total greenhouse gas emissions caused directly and indirectly by an individual, organization, event, or product. Measuring carbon footprints can be challenging due to the many factors involved, from sourcing materials to disposal.
There are various methods to reduce carbon footprints and emissions, including
Governments often implement policies to cap emissions of greenhouse gases and may tax companies based on the amount of greenhouse gases they produce.
Definition Carbon footprint - The total amount of greenhouse gases produced to directly and indirectly support human activities, usually expressed in equivalent tons of carbon dioxide (CO₂).
Example Choosing to cycle instead of drive, or using energy-efficient appliances are ways individuals can reduce their carbon footprint.
Understanding and measuring carbon footprints involves complex calculations considering multiple factors throughout product lifecycles.
Definition Carbon footprint represents the total greenhouse gas emissions caused directly and indirectly by an individual, organization, or product.
Various approaches are being implemented to reduce greenhouse gas emissions and combat climate change.
Example Key strategies include
The first billion years of Earth's history saw the formation of its early atmosphere through intense volcanic activity. This period was characterized by the release of various gases that would shape the planet's future.
During this phase, the Earth's surface was covered in volcanoes that erupted continuously, releasing large amounts of gases into the atmosphere. These gases primarily consisted of carbon dioxide (CO₂), with virtually no oxygen present. Additionally, the volcanic eruptions released nitrogen, water vapor, and small amounts of methane and ammonia.
Highlight The early Earth's atmosphere was predominantly composed of carbon dioxide, with no oxygen present.
Vocabulary Volcanic eruptions - The ejection of molten rock, ash, and gases from a volcano.
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.
You can download the app in the Google Play Store and in the Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
10
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the fundamentals of enthalpy changes, including standard enthalpy of formation, exothermic and endothermic reactions, and energy transfer in chemical processes. This summary covers key concepts such as Hess's Law and reaction profiles, providing a clear understanding of how enthalpy is measured and its significance in thermodynamics.
ChemistryExplore the step-by-step process of synthesizing soluble salts using sulfuric acid and copper oxide. This practical guide includes essential techniques, safety tips, and clear diagrams to enhance your understanding of solubility and reactions in chemistry. Ideal for chemistry students and practical lab sessions.
ChemistryLearn about the organization and properties of elements in the modern periodic table, from metals to nonmetals and their unique characteristics.
ChemistryThis is about basic concepts in chemistry.
ChemistryThis is about the atomic theory of matter.
ChemistryExploring the electron configurations and valence electrons of various elements in the periodic table.
ChemistryQuotes from every main character
English LiteratureApp Store
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
Annie Owen-Stiff
@annieowenstiff_dvtk
The evolution of the Earth's atmosphere over billion years transformed from a volcanic CO₂-rich environment to our current breathable atmosphere, highlighting the crucial role of plant life and the growing concern about the impact of greenhouse gases on climate change... Show more
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
The second phase of atmospheric evolution was marked by significant changes in the Earth's surface and composition. This period saw the formation of oceans and the beginning of carbon sequestration processes.
As the Earth cooled, the water vapor in the atmosphere began to condense, forming the planet's oceans. This process had a profound effect on the atmospheric composition, as large amounts of CO₂ were removed from the air by dissolving in the newly formed oceans. The dissolved CO₂ underwent a series of chemical reactions, forming carbon precipitates that settled on the seabed as sediments.
During this phase, the first green plants and algae evolved. These organisms played a crucial role in further reducing atmospheric CO₂ levels by absorbing it for photosynthesis. Some of the carbon absorbed by these early life forms eventually became fossil fuels after their death and burial.
Definition: Carbon sequestration - The process of capturing and storing atmospheric carbon dioxide.
Example: The formation of limestone deposits on the ocean floor is an example of natural carbon sequestration.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Greenhouse gases, primarily CO₂, methane, and water vapor, play a significant role in regulating Earth's temperature. These gases act as an insulating layer in the Earth's atmosphere, trapping heat and contributing to the greenhouse effect.
The impact of greenhouse gases on climate change is substantial. These gases don't absorb short-wavelength radiation but do absorb and re-radiate long-wavelength radiation in all directions, including back to Earth. This process, known as the greenhouse effect, warms the planet.
Human activities have significantly increased the concentration of greenhouse gases in the atmosphere, leading to accelerated climate change. Some key factors contributing to this increase include:
Highlight: The impact of greenhouse gases on climate change is evident in rising sea levels, changes in rainfall patterns, and increased frequency and severity of storms.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
The third phase of atmospheric evolution saw a dramatic increase in oxygen levels, leading to the composition similar to what we have today.
About 200 million years ago, the Earth's atmosphere reached a composition similar to its current state. This transformation was primarily driven by the proliferation of plants and algae, which produced oxygen as a byproduct of photosynthesis.
The current atmosphere consists of approximately 80% nitrogen and 20% oxygen, with small amounts of other gases, including CO₂, noble gases, and water vapor.
Quote: "200 million years ago atmosphere reached a composition similar to one it is today."
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Carbon footprints are a measure of the total greenhouse gas emissions caused directly and indirectly by an individual, organization, event, or product. Measuring carbon footprints can be challenging due to the many factors involved, from sourcing materials to disposal.
There are various methods to reduce carbon footprints and emissions, including:
Governments often implement policies to cap emissions of greenhouse gases and may tax companies based on the amount of greenhouse gases they produce.
Definition: Carbon footprint - The total amount of greenhouse gases produced to directly and indirectly support human activities, usually expressed in equivalent tons of carbon dioxide (CO₂).
Example: Choosing to cycle instead of drive, or using energy-efficient appliances are ways individuals can reduce their carbon footprint.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Understanding and measuring carbon footprints involves complex calculations considering multiple factors throughout product lifecycles.
Definition: Carbon footprint represents the total greenhouse gas emissions caused directly and indirectly by an individual, organization, or product.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Various approaches are being implemented to reduce greenhouse gas emissions and combat climate change.
Example: Key strategies include:
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
The first billion years of Earth's history saw the formation of its early atmosphere through intense volcanic activity. This period was characterized by the release of various gases that would shape the planet's future.
During this phase, the Earth's surface was covered in volcanoes that erupted continuously, releasing large amounts of gases into the atmosphere. These gases primarily consisted of carbon dioxide (CO₂), with virtually no oxygen present. Additionally, the volcanic eruptions released nitrogen, water vapor, and small amounts of methane and ammonia.
Highlight: The early Earth's atmosphere was predominantly composed of carbon dioxide, with no oxygen present.
Vocabulary: Volcanic eruptions - The ejection of molten rock, ash, and gases from a volcano.
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.
You can download the app in the Google Play Store and in the Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
10
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the fundamentals of enthalpy changes, including standard enthalpy of formation, exothermic and endothermic reactions, and energy transfer in chemical processes. This summary covers key concepts such as Hess's Law and reaction profiles, providing a clear understanding of how enthalpy is measured and its significance in thermodynamics.
ChemistryExplore the step-by-step process of synthesizing soluble salts using sulfuric acid and copper oxide. This practical guide includes essential techniques, safety tips, and clear diagrams to enhance your understanding of solubility and reactions in chemistry. Ideal for chemistry students and practical lab sessions.
ChemistryLearn about the organization and properties of elements in the modern periodic table, from metals to nonmetals and their unique characteristics.
ChemistryThis is about basic concepts in chemistry.
ChemistryThis is about the atomic theory of matter.
ChemistryExploring the electron configurations and valence electrons of various elements in the periodic table.
ChemistryQuotes from every main character
English LiteratureApp Store
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
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