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Britain & the wider world: 1745 -1901
1l the quest for political stability: germany, 1871-1991
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1c the tudors: england, 1485-1603
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Chemistry
10 Dec 2025
1,036
7 pages
The relative atomic mass in chemistry is a fundamental concept that helps understand atomic structure and chemical calculations.... Show more
This section explores various types of chemical bonding and molecular structure concepts. It covers metallic, covalent, and ionic bonding, along with important molecular calculations.
Definition Atom economy measures reaction efficiency by comparing desired product mass to total product masses.
Vocabulary Electronegativity refers to an atom's ability to attract bonding electrons in a covalent bond.
Example A dative covalent bond forms when one atom provides both electrons in the shared pair.
Highlight Understanding different bonding types is essential for predicting molecular properties and chemical behavior.
This section details energy changes in chemical reactions, including enthalpy changes and bond energies.
Definition Enthalpy change represents heat energy changes measured at constant pressure.
Vocabulary Activation energy is the minimum energy required to initiate a reaction through bond breaking.
Example Exothermic reactions release heat energy (negative values), while endothermic reactions absorb heat energy (positive values).
Highlight Bond enthalpy calculations are crucial for predicting overall reaction energetics.
This section covers reaction rates and equilibrium concepts, including Le Chatelier's Principle.
Definition Reaction rate measures the change in concentration of reactants or products over time.
Quote "Le Chatelier's Principle states that when a reaction at equilibrium is subjected to change, the position of equilibrium moves to counteract that change."
Highlight Understanding kinetics and equilibria is essential for controlling industrial chemical processes.
This section introduces basic organic chemistry concepts, including hydrocarbon classification and molecular representations.
Definition A hydrocarbon is a compound containing only hydrogen and carbon atoms.
Vocabulary Saturated compounds contain only single carbon-carbon bonds, while unsaturated compounds have at least one double bond.
Example Different formula representations include displayed, structural, and skeletal formulas.
This section focuses on various ways to represent molecular structures in organic chemistry.
Definition The molecular formula shows the actual number of atoms of each element in a compound.
Example CH3CH2OH can be represented in multiple ways displayed, structural, or skeletal formula.
Highlight Understanding different molecular representations is crucial for organic chemistry comprehension.
This section covers the classification of organic compounds and their functional groups.
Definition A homologous series is a family of compounds with the same functional group and general formula, differing by CH2 units.
Vocabulary Functional groups are specific atoms or groups that determine compound properties.
Highlight Recognition of functional groups is essential for predicting chemical behavior and reactions.
This section introduces fundamental atomic concepts and definitions essential for understanding chemistry at an advanced level. The content focuses on isotopes, relative atomic mass, and ionization energy.
Definition Relative atomic mass is defined as the weighted mean mass of an atom compared with 1/12th of the mass of carbon-12.
Vocabulary Isotopes are atoms of the same element with identical proton and electron numbers but different neutron counts.
Example The first ionisation energy process can be represented as X(g) → X(g)+ + e-, where energy is required to remove one electron from a gaseous atom.
Highlight Understanding relative atomic mass calculations is crucial for determining molecular masses and stoichiometry in chemical reactions.
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.
34
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Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore key concepts of chromatography, including the retention factor (Rf), stationary and mobile phases, and methods for identifying substances. This summary provides insights into pure substances, mixtures, and the principles of thin-layer chromatography (TLC), essential for GCSE chemistry students.
ChemistryExplore the concepts of empirical and molecular formulas in chemistry. This study note covers the calculation of moles, determination of empirical formulas from mass data, and the relationship between empirical and molecular formulas. Ideal for AQA Chemistry students preparing for exams.
ChemistryExplore a comprehensive set of exam questions focused on bond enthalpies, enthalpy changes, and chemical thermodynamics. This resource covers key concepts such as the Haber process, standard enthalpy of formation, and energy changes in chemical reactions. Ideal for students preparing for exams in chemistry and thermodynamics.
ChemistryExplore the principles of gas behavior at room temperature and pressure, including Avogadro's Law, the Ideal Gas Law, and calculations for molarity and concentration. This summary covers key concepts such as molar gas volume, the gas constant, and dilution techniques, essential for understanding the amount of substances in chemistry.
ChemistryExplore essential concepts in mole calculations, including theoretical yield, percent yield, and stoichiometry. This summary covers key formulas and examples relevant to AQA AS Chemistry, helping students master mole conversions and mass calculations effectively.
ChemistryExplore key concepts of dynamic equilibrium, pH calculations, and acid-base titrations in this comprehensive study note. Understand Le Chatelier's Principle, the equilibrium constant, and the differences between strong and weak acids. Ideal for AS/A Level chemistry students preparing for exams.
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
The relative atomic mass in chemistry is a fundamental concept that helps understand atomic structure and chemical calculations. This comprehensive guide covers key definitions in atomic structure, amount of substance, bonding, energetics, kinetics, equilibria, and organic chemistry.
Key points include:... Show more
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Join milions of students
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This section explores various types of chemical bonding and molecular structure concepts. It covers metallic, covalent, and ionic bonding, along with important molecular calculations.
Definition: Atom economy measures reaction efficiency by comparing desired product mass to total product masses.
Vocabulary: Electronegativity refers to an atom's ability to attract bonding electrons in a covalent bond.
Example: A dative covalent bond forms when one atom provides both electrons in the shared pair.
Highlight: Understanding different bonding types is essential for predicting molecular properties and chemical behavior.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
This section details energy changes in chemical reactions, including enthalpy changes and bond energies.
Definition: Enthalpy change represents heat energy changes measured at constant pressure.
Vocabulary: Activation energy is the minimum energy required to initiate a reaction through bond breaking.
Example: Exothermic reactions release heat energy (negative values), while endothermic reactions absorb heat energy (positive values).
Highlight: Bond enthalpy calculations are crucial for predicting overall reaction energetics.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
This section covers reaction rates and equilibrium concepts, including Le Chatelier's Principle.
Definition: Reaction rate measures the change in concentration of reactants or products over time.
Quote: "Le Chatelier's Principle states that when a reaction at equilibrium is subjected to change, the position of equilibrium moves to counteract that change."
Highlight: Understanding kinetics and equilibria is essential for controlling industrial chemical processes.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
This section introduces basic organic chemistry concepts, including hydrocarbon classification and molecular representations.
Definition: A hydrocarbon is a compound containing only hydrogen and carbon atoms.
Vocabulary: Saturated compounds contain only single carbon-carbon bonds, while unsaturated compounds have at least one double bond.
Example: Different formula representations include displayed, structural, and skeletal formulas.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
This section focuses on various ways to represent molecular structures in organic chemistry.
Definition: The molecular formula shows the actual number of atoms of each element in a compound.
Example: CH3CH2OH can be represented in multiple ways: displayed, structural, or skeletal formula.
Highlight: Understanding different molecular representations is crucial for organic chemistry comprehension.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
This section covers the classification of organic compounds and their functional groups.
Definition: A homologous series is a family of compounds with the same functional group and general formula, differing by CH2 units.
Vocabulary: Functional groups are specific atoms or groups that determine compound properties.
Highlight: Recognition of functional groups is essential for predicting chemical behavior and reactions.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
This section introduces fundamental atomic concepts and definitions essential for understanding chemistry at an advanced level. The content focuses on isotopes, relative atomic mass, and ionization energy.
Definition: Relative atomic mass is defined as the weighted mean mass of an atom compared with 1/12th of the mass of carbon-12.
Vocabulary: Isotopes are atoms of the same element with identical proton and electron numbers but different neutron counts.
Example: The first ionisation energy process can be represented as X(g) → X(g)+ + e-, where energy is required to remove one electron from a gaseous atom.
Highlight: Understanding relative atomic mass calculations is crucial for determining molecular masses and stoichiometry in chemical reactions.
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.
34
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore key concepts of chromatography, including the retention factor (Rf), stationary and mobile phases, and methods for identifying substances. This summary provides insights into pure substances, mixtures, and the principles of thin-layer chromatography (TLC), essential for GCSE chemistry students.
ChemistryExplore the concepts of empirical and molecular formulas in chemistry. This study note covers the calculation of moles, determination of empirical formulas from mass data, and the relationship between empirical and molecular formulas. Ideal for AQA Chemistry students preparing for exams.
ChemistryExplore a comprehensive set of exam questions focused on bond enthalpies, enthalpy changes, and chemical thermodynamics. This resource covers key concepts such as the Haber process, standard enthalpy of formation, and energy changes in chemical reactions. Ideal for students preparing for exams in chemistry and thermodynamics.
ChemistryExplore the principles of gas behavior at room temperature and pressure, including Avogadro's Law, the Ideal Gas Law, and calculations for molarity and concentration. This summary covers key concepts such as molar gas volume, the gas constant, and dilution techniques, essential for understanding the amount of substances in chemistry.
ChemistryExplore essential concepts in mole calculations, including theoretical yield, percent yield, and stoichiometry. This summary covers key formulas and examples relevant to AQA AS Chemistry, helping students master mole conversions and mass calculations effectively.
ChemistryExplore key concepts of dynamic equilibrium, pH calculations, and acid-base titrations in this comprehensive study note. Understand Le Chatelier's Principle, the equilibrium constant, and the differences between strong and weak acids. Ideal for AS/A Level chemistry students preparing for exams.
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