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Infection and response
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Energy transfers (a2 only)
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Organisms respond to changes in their internal and external environments (a-level only)
Biological molecules
Organisation
Substance exchange
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1l the quest for political stability: germany, 1871-1991
Britain & the wider world: 1745 -1901
The cold war
Inter-war germany
Medieval period: 1066 -1509
2d religious conflict and the church in england, c1529-c1570
2o democracy and nazism: germany, 1918-1945
1f industrialisation and the people: britain, c1783-1885
1c the tudors: england, 1485-1603
2m wars and welfare: britain in transition, 1906-1957
World war two & the holocaust
2n revolution and dictatorship: russia, 1917-1953
2s the making of modern britain, 1951-2007
World war one
Britain: 1509 -1745
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Chemistry
1 Dec 2025
216
3 pages
Jess Drew @rj2105
The Earth's atmosphere evolved from volcanic gases to its current composition, with significant changes in carbon dioxide levels. ... Show more
Various pollutants have significant impacts on the environment and human health. The main pollutants discussed are carbon monoxide, carbon particulates, and acidic oxides.
Carbon monoxide is a colorless and odorless gas that poses severe health risks. How carbon monoxide affects health is particularly concerning due to its high toxicity. It binds to hemoglobin, preventing oxygen from circulating throughout the body.
Definition Hemoglobin is a protein in red blood cells that carries oxygen throughout the body.
Carbon particulates, small particles of soot formed by incomplete combustion, adhere to the lungs, potentially causing bronchitis and heart disease.
Acidic oxides, which are non-metal oxides, dissolve in water to create acid rain. This phenomenon has devastating effects on ecosystems, often leading to their destruction as ecological niches disappear.
The formation of acid rain occurs when certain pollutants dissolve in water
Example Acid rain can make lakes more acidic, destroying ecological niches and causing widespread damage to aquatic ecosystems.
Problems caused by acid rain include
The production of carbon monoxide often involves the incomplete combustion of hydrocarbons. For instance, methane can produce carbon monoxide through the following reaction
CH4 + 1.5O2 → CO + 2H2O
In this reaction, methane burns in oxygen, with carbon being oxidized to form carbon monoxide and hydrogen being oxidized to form water.
The Earth's climate is significantly affected by the presence of certain gases in the atmosphere, particularly carbon dioxide and methane. These gases contribute to the greenhouse effect, which plays a crucial role in maintaining the Earth's temperature.
Definition The greenhouse effect is the process by which carbon dioxide and methane in the Earth's atmosphere absorb heat from the sun and emit it in all directions, keeping the Earth warm.
Global warming refers to the sustained increase in the Earth's average temperature. This phenomenon is closely linked to the increased concentration of greenhouse gases in the atmosphere, primarily due to human activities.
Vocabulary Climate change - Permanent change in the Earth's weather patterns as a result of human actions, including the release of large quantities of carbon dioxide.
The impact of pollutants on climate change is significant and far-reaching. The release of greenhouse gases, particularly through industrial processes and the burning of fossil fuels, has led to a rapid increase in global temperatures. This warming trend has cascading effects on weather patterns, sea levels, and ecosystems worldwide.
Highlight The interconnectedness of atmospheric composition, pollutants, and climate change underscores the importance of understanding and addressing human impacts on the environment.
Understanding the formation of Earth's early atmosphere, the effects of pollutants, and the mechanisms of climate change is crucial for developing strategies to mitigate environmental damage and protect human health. As we continue to study these phenomena, it becomes increasingly clear that human activities have profound impacts on the delicate balance of our planet's atmosphere and climate systems.
The Earth's atmosphere has undergone significant changes since the planet's formation. Initially, volcanic activity played a crucial role in shaping the atmospheric composition. The early atmosphere was primarily composed of carbon dioxide (20.5%), water vapor (70.5%), sulfur dioxide (6.9%), hydrogen (0.9%), and other gases (1.2%).
Vocabulary Pollutant - A substance released into the environment which may harm living things.
The current atmosphere consists of
The drastic reduction in carbon dioxide levels can be attributed to several factors. Most of the CO2 dissolved into the sea, was used for photosynthesis by early life forms, and became trapped in rocks. Seashells, for instance, are formed by carbon dioxide.
Example Seashells are a prime example of how carbon dioxide can be locked up in solid form, contributing to the reduction of atmospheric CO2 levels.
The timeline of Earth's atmospheric evolution includes
Highlight The evolution of photosynthesizing organisms was a crucial turning point in Earth's history, leading to the oxygen-rich atmosphere we have today.
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.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
12
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
This is a presentation about colligative properties of solution with some examples and detailed solution.
ChemistryThe Nature of Light / Atomic Spectra / The Wave-Particle Duality of Matter and Energy / The Quantum-Mechanical Model of the Atom
AP ChemistryExplore the fascinating world of polymers and their formation through polymerization. This summary covers key concepts such as monomers, the polymerization process of ethene, and the distinction between natural and synthetic polymers. Ideal for students studying chemistry and materials science.
Chemistryincludes: chem intro, balancing equations, mole and molar mass, stoichiometry, limiting reactants, energy/coulomb’s law, subatomic particles, isotopes, and ions.
AP ChemistryLearn how calcium, fluorine, aluminum, and sulfur form bonds through Lewis Dot structures and electron gain/loss.
ChemistryThis article covers practice problems related to density, mass, volume, and temperature conversions, providing step-by-step solutions for each problem.
ChemistryApp 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
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
Jess Drew
@rj2105
The Earth's atmosphere evolved from volcanic gases to its current composition, with significant changes in carbon dioxide levels. Formation of Earth's early atmosphereinvolved volcanic activity releasing gases like CO2, water vapor, and nitrogen. Over time, CO2 decreased through various... Show more
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Various pollutants have significant impacts on the environment and human health. The main pollutants discussed are carbon monoxide, carbon particulates, and acidic oxides.
Carbon monoxide is a colorless and odorless gas that poses severe health risks. How carbon monoxide affects health is particularly concerning due to its high toxicity. It binds to hemoglobin, preventing oxygen from circulating throughout the body.
Definition: Hemoglobin is a protein in red blood cells that carries oxygen throughout the body.
Carbon particulates, small particles of soot formed by incomplete combustion, adhere to the lungs, potentially causing bronchitis and heart disease.
Acidic oxides, which are non-metal oxides, dissolve in water to create acid rain. This phenomenon has devastating effects on ecosystems, often leading to their destruction as ecological niches disappear.
The formation of acid rain occurs when certain pollutants dissolve in water:
Example: Acid rain can make lakes more acidic, destroying ecological niches and causing widespread damage to aquatic ecosystems.
Problems caused by acid rain include:
The production of carbon monoxide often involves the incomplete combustion of hydrocarbons. For instance, methane can produce carbon monoxide through the following reaction:
CH4 + 1.5O2 → CO + 2H2O
In this reaction, methane burns in oxygen, with carbon being oxidized to form carbon monoxide and hydrogen being oxidized to form water.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
The Earth's climate is significantly affected by the presence of certain gases in the atmosphere, particularly carbon dioxide and methane. These gases contribute to the greenhouse effect, which plays a crucial role in maintaining the Earth's temperature.
Definition: The greenhouse effect is the process by which carbon dioxide and methane in the Earth's atmosphere absorb heat from the sun and emit it in all directions, keeping the Earth warm.
Global warming refers to the sustained increase in the Earth's average temperature. This phenomenon is closely linked to the increased concentration of greenhouse gases in the atmosphere, primarily due to human activities.
Vocabulary: Climate change - Permanent change in the Earth's weather patterns as a result of human actions, including the release of large quantities of carbon dioxide.
The impact of pollutants on climate change is significant and far-reaching. The release of greenhouse gases, particularly through industrial processes and the burning of fossil fuels, has led to a rapid increase in global temperatures. This warming trend has cascading effects on weather patterns, sea levels, and ecosystems worldwide.
Highlight: The interconnectedness of atmospheric composition, pollutants, and climate change underscores the importance of understanding and addressing human impacts on the environment.
Understanding the formation of Earth's early atmosphere, the effects of pollutants, and the mechanisms of climate change is crucial for developing strategies to mitigate environmental damage and protect human health. As we continue to study these phenomena, it becomes increasingly clear that human activities have profound impacts on the delicate balance of our planet's atmosphere and climate systems.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
The Earth's atmosphere has undergone significant changes since the planet's formation. Initially, volcanic activity played a crucial role in shaping the atmospheric composition. The early atmosphere was primarily composed of carbon dioxide (20.5%), water vapor (70.5%), sulfur dioxide (6.9%), hydrogen (0.9%), and other gases (1.2%).
Vocabulary: Pollutant - A substance released into the environment which may harm living things.
The current atmosphere consists of:
The drastic reduction in carbon dioxide levels can be attributed to several factors. Most of the CO2 dissolved into the sea, was used for photosynthesis by early life forms, and became trapped in rocks. Seashells, for instance, are formed by carbon dioxide.
Example: Seashells are a prime example of how carbon dioxide can be locked up in solid form, contributing to the reduction of atmospheric CO2 levels.
The timeline of Earth's atmospheric evolution includes:
Highlight: The evolution of photosynthesizing organisms was a crucial turning point in Earth's history, leading to the oxygen-rich atmosphere we have today.
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.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
12
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
This is a presentation about colligative properties of solution with some examples and detailed solution.
ChemistryThe Nature of Light / Atomic Spectra / The Wave-Particle Duality of Matter and Energy / The Quantum-Mechanical Model of the Atom
AP ChemistryExplore the fascinating world of polymers and their formation through polymerization. This summary covers key concepts such as monomers, the polymerization process of ethene, and the distinction between natural and synthetic polymers. Ideal for students studying chemistry and materials science.
Chemistryincludes: chem intro, balancing equations, mole and molar mass, stoichiometry, limiting reactants, energy/coulomb’s law, subatomic particles, isotopes, and ions.
AP ChemistryLearn how calcium, fluorine, aluminum, and sulfur form bonds through Lewis Dot structures and electron gain/loss.
ChemistryThis article covers practice problems related to density, mass, volume, and temperature conversions, providing step-by-step solutions for each problem.
ChemistryApp 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
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
