Maths
Biology
Chemistry
English Language
History
Responding to change (a2 only)
Infection and response
Homeostasis and response
Energy transfers (a2 only)
Cell biology
Organisms respond to changes in their internal and external environments (a-level only)
Biological molecules
Organisation
Substance exchange
Bioenergetics
Genetic information & variation
Inheritance, variation and evolution
Genetics & ecosystems (a2 only)
Ecology
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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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Physics
23 Nov 2025
103
5 pages
Ummi @ummi_.com
Quantum mechanics might sound intimidating, but it's actually the fascinating science that explains how the tiniest particles in... Show more
Ever wondered why atoms don't just fall apart or how your phone's processor actually works? Quantum mechanics is the branch of physics that explains the bizarre behaviour of particles smaller than atoms. Unlike the predictable world we see around us, the quantum world operates by completely different rules.
This theory replaced classical mechanics when scientists realised that Newton's laws simply don't work at the atomic scale. Instead of smooth, predictable motion, we discovered that tiny particles behave in ways that seem almost magical.
The quantum world is where particles can be in multiple places at once, where measuring something actually changes it, and where 'spooky action at a distance' is totally normal. Don't worry if this sounds mental - even Einstein struggled with these concepts!
Quick Tip Think of quantum mechanics as the rulebook for the microscopic world - it's different from our everyday experience, but once you get the basics, it starts to make sense.
The foundation of quantum mechanics rests on several mind-bending ideas that you'll need to master. Quantisation means that energy, momentum, and other properties come in specific chunks or packets - like having stairs instead of a ramp.
Wave-particle duality is probably the weirdest concept you'll encounter. Light and matter can behave as both waves and particles depending on how you observe them. It's like a coin that's both heads and tails until you look at it.
The uncertainty principle tells us there's a fundamental limit to how precisely we can know certain pairs of properties. The more accurately you know a particle's position, the less you can know about its speed, and vice versa.
Quantum superposition means particles can exist in multiple states simultaneously - imagine being in London and Manchester at the same time! The wavefunction is the mathematical tool that describes these bizarre quantum states and gives us probabilities rather than certainties.
Remember These aren't just theoretical ideas - they're the principles that make your electronic devices work every day.
Don't panic about the maths - the Schrödinger equation is simply the master equation that predicts how quantum systems change over time. Think of it as quantum mechanics' version of F = ma, but for probability waves instead of solid objects.
Planck's constant is the fundamental number that sets the scale of quantum effects. It's incredibly tiny, which is why quantum weirdness doesn't show up in everyday life. The de Broglie wavelength connects a particle's momentum to its wave properties - faster particles have shorter wavelengths.
Quantum entanglement creates spooky connections between particles that persist even across vast distances. When you measure one entangled particle, you instantly affect its partner, no matter how far apart they are.
The probability interpretation means we can't predict exactly what will happen in quantum experiments - only the chances of different outcomes. This isn't because we lack information; it's a fundamental feature of reality at the quantum scale.
Study Hack Focus on understanding the concepts first, then worry about the mathematical details - the physics intuition is more important for grasping quantum mechanics.
Quantum mechanics isn't just abstract theory - it's the technology that runs our modern world. Semiconductors in your phone, laptop, and gaming console all depend on quantum principles to control the flow of electrons through materials.
Lasers work because of stimulated emission, a purely quantum phenomenon where atoms release identical photons in perfect synchronisation. From laser pointers to fibre optic internet, this quantum effect connects our world.
Spectroscopy uses quantum mechanics to identify substances by analysing the light they absorb or emit. This technique helps astronomers discover what distant stars are made of and helps chemists identify unknown compounds.
In nuclear physics, quantum mechanics explains how atomic nuclei hold together and why some elements are radioactive. Even cosmology relies on quantum effects to understand the early universe and the formation of galaxies.
Career Connection Understanding quantum mechanics opens doors to careers in electronics, telecommunications, medical imaging, renewable energy, and cutting-edge quantum computing research.
The quantum revolution was built by brilliant scientists who weren't afraid to challenge conventional thinking. Max Planck started it all by proposing that energy comes in discrete packets, earning him the title 'father of quantum theory'.
Albert Einstein explained the photoelectric effect (how light knocks electrons off metals) and showed that light behaves like particles called photons. Niels Bohr developed the first successful quantum model of atoms, explaining why they don't collapse.
Louis de Broglie had the revolutionary idea that matter has wave properties, not just light. Erwin Schrödinger created the famous wave equation that describes quantum systems, whilst Werner Heisenberg gave us the uncertainty principle and matrix mechanics.
These scientists didn't just discover new facts - they completely rewrote our understanding of reality. Their work shows how questioning established ideas can lead to revolutionary breakthroughs that transform technology and society.
Inspiration These physicists were often your age when they first encountered the ideas that would later make them famous - quantum mechanics is a field where young minds can make major contributions.
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.
1
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the concept of wave-particle duality in physics, detailing how light and electrons exhibit both wave and particle characteristics. This summary covers key phenomena such as diffraction, the photoelectric effect, and De Broglie's hypothesis, along with the implications of experimental evidence in validating scientific theories. Ideal for A-Level Physics students.
PhysicsExplore the Photoelectric Effect, including Einstein's photoelectric equation, work function, and threshold frequency. This summary provides a clear explanation of how light interacts with metals to emit photoelectrons, detailing the role of photon energy and stopping potential. Ideal for A-Level Physics students seeking to grasp key concepts in modern physics.
PhysicsApp 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
Ummi
@ummi_.com
Quantum mechanics might sound intimidating, but it's actually the fascinating science that explains how the tiniest particles in our universe behave. This revolutionary theory completely changed physics and now powers everything from your smartphone to medical scanners.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Ever wondered why atoms don't just fall apart or how your phone's processor actually works? Quantum mechanics is the branch of physics that explains the bizarre behaviour of particles smaller than atoms. Unlike the predictable world we see around us, the quantum world operates by completely different rules.
This theory replaced classical mechanics when scientists realised that Newton's laws simply don't work at the atomic scale. Instead of smooth, predictable motion, we discovered that tiny particles behave in ways that seem almost magical.
The quantum world is where particles can be in multiple places at once, where measuring something actually changes it, and where 'spooky action at a distance' is totally normal. Don't worry if this sounds mental - even Einstein struggled with these concepts!
Quick Tip: Think of quantum mechanics as the rulebook for the microscopic world - it's different from our everyday experience, but once you get the basics, it starts to make sense.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
The foundation of quantum mechanics rests on several mind-bending ideas that you'll need to master. Quantisation means that energy, momentum, and other properties come in specific chunks or packets - like having stairs instead of a ramp.
Wave-particle duality is probably the weirdest concept you'll encounter. Light and matter can behave as both waves and particles depending on how you observe them. It's like a coin that's both heads and tails until you look at it.
The uncertainty principle tells us there's a fundamental limit to how precisely we can know certain pairs of properties. The more accurately you know a particle's position, the less you can know about its speed, and vice versa.
Quantum superposition means particles can exist in multiple states simultaneously - imagine being in London and Manchester at the same time! The wavefunction is the mathematical tool that describes these bizarre quantum states and gives us probabilities rather than certainties.
Remember: These aren't just theoretical ideas - they're the principles that make your electronic devices work every day.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Don't panic about the maths - the Schrödinger equation is simply the master equation that predicts how quantum systems change over time. Think of it as quantum mechanics' version of F = ma, but for probability waves instead of solid objects.
Planck's constant is the fundamental number that sets the scale of quantum effects. It's incredibly tiny, which is why quantum weirdness doesn't show up in everyday life. The de Broglie wavelength connects a particle's momentum to its wave properties - faster particles have shorter wavelengths.
Quantum entanglement creates spooky connections between particles that persist even across vast distances. When you measure one entangled particle, you instantly affect its partner, no matter how far apart they are.
The probability interpretation means we can't predict exactly what will happen in quantum experiments - only the chances of different outcomes. This isn't because we lack information; it's a fundamental feature of reality at the quantum scale.
Study Hack: Focus on understanding the concepts first, then worry about the mathematical details - the physics intuition is more important for grasping quantum mechanics.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Quantum mechanics isn't just abstract theory - it's the technology that runs our modern world. Semiconductors in your phone, laptop, and gaming console all depend on quantum principles to control the flow of electrons through materials.
Lasers work because of stimulated emission, a purely quantum phenomenon where atoms release identical photons in perfect synchronisation. From laser pointers to fibre optic internet, this quantum effect connects our world.
Spectroscopy uses quantum mechanics to identify substances by analysing the light they absorb or emit. This technique helps astronomers discover what distant stars are made of and helps chemists identify unknown compounds.
In nuclear physics, quantum mechanics explains how atomic nuclei hold together and why some elements are radioactive. Even cosmology relies on quantum effects to understand the early universe and the formation of galaxies.
Career Connection: Understanding quantum mechanics opens doors to careers in electronics, telecommunications, medical imaging, renewable energy, and cutting-edge quantum computing research.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
The quantum revolution was built by brilliant scientists who weren't afraid to challenge conventional thinking. Max Planck started it all by proposing that energy comes in discrete packets, earning him the title 'father of quantum theory'.
Albert Einstein explained the photoelectric effect (how light knocks electrons off metals) and showed that light behaves like particles called photons. Niels Bohr developed the first successful quantum model of atoms, explaining why they don't collapse.
Louis de Broglie had the revolutionary idea that matter has wave properties, not just light. Erwin Schrödinger created the famous wave equation that describes quantum systems, whilst Werner Heisenberg gave us the uncertainty principle and matrix mechanics.
These scientists didn't just discover new facts - they completely rewrote our understanding of reality. Their work shows how questioning established ideas can lead to revolutionary breakthroughs that transform technology and society.
Inspiration: These physicists were often your age when they first encountered the ideas that would later make them famous - quantum mechanics is a field where young minds can make major contributions.
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.
1
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the concept of wave-particle duality in physics, detailing how light and electrons exhibit both wave and particle characteristics. This summary covers key phenomena such as diffraction, the photoelectric effect, and De Broglie's hypothesis, along with the implications of experimental evidence in validating scientific theories. Ideal for A-Level Physics students.
PhysicsExplore the Photoelectric Effect, including Einstein's photoelectric equation, work function, and threshold frequency. This summary provides a clear explanation of how light interacts with metals to emit photoelectrons, detailing the role of photon energy and stopping potential. Ideal for A-Level Physics students seeking to grasp key concepts in modern physics.
PhysicsApp 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
