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Britain & the wider world: 1745 -1901
1l the quest for political stability: germany, 1871-1991
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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
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Chemistry
13 Dec 2025
163
2 pages
paige gibbs @paigegibbs_vuvr
Hydrocarbons are compounds made up of hydrogen and carbon atoms only, and they're everywhere in our daily lives... Show more
Alkanes are like the steady, reliable friends of the hydrocarbon world. Each carbon atom links to four other atoms using single bonds, making them saturated hydrocarbons - they've got the maximum number of hydrogen atoms possible.
These molecules follow the general formula CₙH₂ₙ₊₂. Starting simple methane (CH₄) has one carbon, ethane (C₂H₆) has two carbons, propane (C₃H₈) has three, and butane (C₄H₁₀) has four. Notice how each carbon is surrounded by hydrogen atoms in a neat, predictable pattern.
Alkanes are fairly unreactive in normal conditions, but they burn brilliantly - that's why we use them as fuels. Shorter chains like methane release energy more quickly when burning, making them perfect for cooking gas.
💡 Remember The single lines between atoms represent single covalent bonds - one pair of electrons being shared between two atoms.
All alkanes belong to a homologous series, meaning they share the same functional group and follow the same general formula, just with different chain lengths.
Alkenes are the rebels compared to alkanes - they're unsaturated hydrocarbons with a crucial difference. Instead of all single bonds, they contain at least one C=C double bond, which makes them much more reactive and interesting.
The general formula for alkenes is CₙH₂ₙ - notice there are fewer hydrogen atoms than in alkanes. This happens because the double bond "uses up" some bonding opportunities that hydrogen would normally fill.
Starting with ethene (C₂H₄), then propene (C₃H₆), and butene (C₄H₈), you can see how the pattern develops. The double bond is the star of the show - it's what makes alkenes so useful for making plastics and other materials.
💡 Key insight The C=C double bond makes alkenes reactive because it can break open to form new bonds with other molecules.
Like alkanes, alkenes form a homologous series with similar chemical properties but gradually changing physical properties like boiling points as the chains get longer.
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.
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Chemistry chemical changes flashcards
ChemistryThis is about atoms and molecules.
ChemistryExplore essential laboratory techniques including chromatography, simple and fractional distillation, and filtration. Understand the principles of separation methods, the properties of metals and non-metals, and the development of the periodic table. This summary covers key concepts such as atomic structure, mixtures, and balancing chemical equations, making it a valuable resource for chemistry students.
Chemistry35 elements of the periodic table of elements. Consists of all events from the first two periods and some transition metals
ChemistryLearn about physical and chemical changes, properties, and examples in this informative article.
ChemistryExplore the formation of condensation polymers, including polyamides and polyesters, through the reaction of carboxylic acids with amines and alcohols. This summary covers key concepts such as monomers, repeating units, and the release of water during polymerization. Ideal for GCSE chemistry students studying polymer chemistry.
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
paige gibbs
@paigegibbs_vuvr
Hydrocarbons are compounds made up of hydrogen and carbon atoms only, and they're everywhere in our daily lives - from the petrol in cars to the gas that heats our homes. Understanding alkanes and alkenes is crucial for your chemistry... Show more
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Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Alkanes are like the steady, reliable friends of the hydrocarbon world. Each carbon atom links to four other atoms using single bonds, making them saturated hydrocarbons - they've got the maximum number of hydrogen atoms possible.
These molecules follow the general formula CₙH₂ₙ₊₂. Starting simple: methane (CH₄) has one carbon, ethane (C₂H₆) has two carbons, propane (C₃H₈) has three, and butane (C₄H₁₀) has four. Notice how each carbon is surrounded by hydrogen atoms in a neat, predictable pattern.
Alkanes are fairly unreactive in normal conditions, but they burn brilliantly - that's why we use them as fuels. Shorter chains like methane release energy more quickly when burning, making them perfect for cooking gas.
💡 Remember: The single lines between atoms represent single covalent bonds - one pair of electrons being shared between two atoms.
All alkanes belong to a homologous series, meaning they share the same functional group and follow the same general formula, just with different chain lengths.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Alkenes are the rebels compared to alkanes - they're unsaturated hydrocarbons with a crucial difference. Instead of all single bonds, they contain at least one C=C double bond, which makes them much more reactive and interesting.
The general formula for alkenes is CₙH₂ₙ - notice there are fewer hydrogen atoms than in alkanes. This happens because the double bond "uses up" some bonding opportunities that hydrogen would normally fill.
Starting with ethene (C₂H₄), then propene (C₃H₆), and butene (C₄H₈), you can see how the pattern develops. The double bond is the star of the show - it's what makes alkenes so useful for making plastics and other materials.
💡 Key insight: The C=C double bond makes alkenes reactive because it can break open to form new bonds with other molecules.
Like alkanes, alkenes form a homologous series with similar chemical properties but gradually changing physical properties like boiling points as the chains get longer.
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.
2
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Chemistry chemical changes flashcards
ChemistryThis is about atoms and molecules.
ChemistryExplore essential laboratory techniques including chromatography, simple and fractional distillation, and filtration. Understand the principles of separation methods, the properties of metals and non-metals, and the development of the periodic table. This summary covers key concepts such as atomic structure, mixtures, and balancing chemical equations, making it a valuable resource for chemistry students.
Chemistry35 elements of the periodic table of elements. Consists of all events from the first two periods and some transition metals
ChemistryLearn about physical and chemical changes, properties, and examples in this informative article.
ChemistryExplore the formation of condensation polymers, including polyamides and polyesters, through the reaction of carboxylic acids with amines and alcohols. This summary covers key concepts such as monomers, repeating units, and the release of water during polymerization. Ideal for GCSE chemistry students studying polymer chemistry.
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
Sociology