Maths
Chemistry
Biology
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
Cells
Show all topics
Britain & the wider world: 1745 -1901
1l the quest for political stability: germany, 1871-1991
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
Show all topics
Engineering
9 Dec 2025
397
5 pages
Olamide @olamide_26
Understanding materials is crucial for any design and technology project! This guide covers the five main material groups... Show more
Ever wondered why some furniture lasts decades whilst others fall apart quickly? It's all about choosing the right type of wood! Natural woods come from two main tree types hardwoods (like oak and mahogany from deciduous trees) and softwoods (like pine from coniferous trees).
Hardwoods grow slowly, making them expensive but incredibly durable. Oak creates quality furniture but needs brass fittings since steel will stain it. Teak contains natural oils that resist decay, perfect for garden furniture. These materials cost more but they're built to last.
Softwoods like pine grow quickly and are much cheaper. They're easier to cut and shape, making them ideal for building work and budget furniture. About 80% of UK timber is actually imported from other countries.
Manufactured boards solve the problems of natural wood by combining wood fibres or layers. MDF (Medium Density Fibreboard) is cheap, easy to work with, and takes paint without primer. Plywood alternates grain directions for extra strength. These boards come in large, consistent sheets - perfect when you need reliability over natural beauty.
Quick Tip Think of manufactured boards as the reliable workhorses - they won't warp or split like natural timber might!
Plastic bottles, phone cases, car bumpers - polymers are everywhere! The secret is knowing whether you're dealing with thermoplastics (can be reheated and reshaped) or thermosetting plastics (permanently set once heated).
Thermoplastics are the recyclable heroes. Acrylic (Perspex) is the workshop favourite - easy to cut, comes in loads of colours, and polishes beautifully. HDPE and LDPE (high and low density polyethylene) make everything from rigid crates to flexible bags. The key difference? HDPE is harder, LDPE is more flexible.
Thermosetting plastics can't be recycled once set because their molecules are permanently cross-linked. Melamine formaldehyde creates those smooth kitchen worktops, whilst polyester resins combined with fibreglass make incredibly tough car body panels.
Modern manufacturing uses CAD/CAM for precision. Injection moulding forces liquid plastic into moulds for complex shapes, blow moulding creates hollow bottles, and vacuum forming shapes heated plastic over moulds. Each process creates identical products every time - that's why your phone case fits perfectly!
Remember Thermoplastics can be recycled , thermosetting plastics cannot!
That cereal box does way more than you think! Packaging has six crucial jobs protect, inform, contain, transport, preserve, and display. Getting these right means products reach you safely with all the info you need.
Cartridge paper is your go-to for design work - thick enough to handle pencils and felt pens without bleeding through. Tracing paper lets you copy and layer designs easily. For serious projects, you need the right card.
Corrugated card uses a clever triangular middle section that's incredibly strong for its weight - perfect for protecting large items. Foil-lined board keeps takeaway food warm with its aluminium layer. Solid white board gives the best printing quality for expensive packaging.
Paper manufacturing starts with trees being chipped, then boiled into pulp. Add chemicals and bonding agents, pour over fine mesh, and squeeze between rollers. The water escapes, leaving cellulose fibres that form your paper. It's basically controlled tree mush that becomes incredibly useful!
Did You Know The triangular structure in corrugated card is one of the strongest shapes in engineering - that's why it protects heavy items so well!
Metals are the backbone of engineering, but choosing the wrong type can spell disaster! The big divide is between ferrous metals (contain iron, magnetic, rust easily) and non-ferrous metals .
Ferrous metals include mild steel - the workshop workhorse that's tough with high tensile strength but rusts easily. Stainless steel solves the rust problem, perfect for cutlery and medical instruments. Cast iron is incredibly strong in compression but brittle - ideal for manhole covers that need to support weight without bending.
Non-ferrous metals are your corrosion-resistant champions. Aluminium is super light and ductile - brilliant for aircraft and window frames. Copper conducts electricity and heat excellently, making it perfect for wiring and plumbing. Brass machines beautifully and conducts electricity for electrical fittings.
Most metals you use are actually alloys - mixtures that improve properties. Pure metals are rarely strong enough alone. Understanding material properties like ductility (stretches without breaking), malleability (shapes without cracking), and tensile strength (resists breaking under tension) helps you pick the right metal for each job.
Key Point Remember the iron rule - ferrous = iron = magnetic = rusts. Non-ferrous = no iron = non-magnetic = better corrosion resistance!
Your clothes tell an amazing story of global materials! Natural fibres come from plants (cotton, bamboo, linen) or animals (wool, silk), whilst synthetic fibres are oil-based polymers, and regenerated fibres recycle existing materials.
Natural fibres each have distinct personalities. Cotton from China and the USA is cool, cheap, and strong - perfect for jeans and shirts. Wool from UK sheep and Australian farms is soft, hardwearing, and naturally renewable. Silk from Chinese moth cocoons is expensive but drapes beautifully with brilliant insulation properties.
Synthetic fibres solve natural fibre problems. Polyester is cheap, durable, and doesn't wrinkle - ideal for school uniforms. Acrylic mimics wool's warmth without the cost. These polymers are extracted from oil and forced through tiny holes to create continuous filaments.
Blended fabrics give you the best of both worlds. Polycotton combines polyester's durability with cotton's comfort. Kevlar uses chemical bonds and clever weaving to become five times stronger than steel. Modern technical fabrics like Sympatex are both breathable and waterproof - perfect for serious sportswear.
Pro Tip Fabric denier measures thickness - 30 denier tights are thin and delicate, 100 denier are thick and robust!
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.
5
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
App 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
Olamide
@olamide_26
Understanding materials is crucial for any design and technology project! This guide covers the five main material groups you'll work with: timber, polymers (plastics), paper and card, metals, and textiles. Each material has unique properties that make it perfect for... Show more
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Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Ever wondered why some furniture lasts decades whilst others fall apart quickly? It's all about choosing the right type of wood! Natural woods come from two main tree types: hardwoods (like oak and mahogany from deciduous trees) and softwoods (like pine from coniferous trees).
Hardwoods grow slowly, making them expensive but incredibly durable. Oak creates quality furniture but needs brass fittings since steel will stain it. Teak contains natural oils that resist decay, perfect for garden furniture. These materials cost more but they're built to last.
Softwoods like pine grow quickly and are much cheaper. They're easier to cut and shape, making them ideal for building work and budget furniture. About 80% of UK timber is actually imported from other countries.
Manufactured boards solve the problems of natural wood by combining wood fibres or layers. MDF (Medium Density Fibreboard) is cheap, easy to work with, and takes paint without primer. Plywood alternates grain directions for extra strength. These boards come in large, consistent sheets - perfect when you need reliability over natural beauty.
Quick Tip: Think of manufactured boards as the reliable workhorses - they won't warp or split like natural timber might!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Plastic bottles, phone cases, car bumpers - polymers are everywhere! The secret is knowing whether you're dealing with thermoplastics (can be reheated and reshaped) or thermosetting plastics (permanently set once heated).
Thermoplastics are the recyclable heroes. Acrylic (Perspex) is the workshop favourite - easy to cut, comes in loads of colours, and polishes beautifully. HDPE and LDPE (high and low density polyethylene) make everything from rigid crates to flexible bags. The key difference? HDPE is harder, LDPE is more flexible.
Thermosetting plastics can't be recycled once set because their molecules are permanently cross-linked. Melamine formaldehyde creates those smooth kitchen worktops, whilst polyester resins combined with fibreglass make incredibly tough car body panels.
Modern manufacturing uses CAD/CAM for precision. Injection moulding forces liquid plastic into moulds for complex shapes, blow moulding creates hollow bottles, and vacuum forming shapes heated plastic over moulds. Each process creates identical products every time - that's why your phone case fits perfectly!
Remember: Thermoplastics can be recycled , thermosetting plastics cannot!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
That cereal box does way more than you think! Packaging has six crucial jobs: protect, inform, contain, transport, preserve, and display. Getting these right means products reach you safely with all the info you need.
Cartridge paper is your go-to for design work - thick enough to handle pencils and felt pens without bleeding through. Tracing paper lets you copy and layer designs easily. For serious projects, you need the right card.
Corrugated card uses a clever triangular middle section that's incredibly strong for its weight - perfect for protecting large items. Foil-lined board keeps takeaway food warm with its aluminium layer. Solid white board gives the best printing quality for expensive packaging.
Paper manufacturing starts with trees being chipped, then boiled into pulp. Add chemicals and bonding agents, pour over fine mesh, and squeeze between rollers. The water escapes, leaving cellulose fibres that form your paper. It's basically controlled tree mush that becomes incredibly useful!
Did You Know: The triangular structure in corrugated card is one of the strongest shapes in engineering - that's why it protects heavy items so well!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Metals are the backbone of engineering, but choosing the wrong type can spell disaster! The big divide is between ferrous metals (contain iron, magnetic, rust easily) and non-ferrous metals .
Ferrous metals include mild steel - the workshop workhorse that's tough with high tensile strength but rusts easily. Stainless steel solves the rust problem, perfect for cutlery and medical instruments. Cast iron is incredibly strong in compression but brittle - ideal for manhole covers that need to support weight without bending.
Non-ferrous metals are your corrosion-resistant champions. Aluminium is super light and ductile - brilliant for aircraft and window frames. Copper conducts electricity and heat excellently, making it perfect for wiring and plumbing. Brass machines beautifully and conducts electricity for electrical fittings.
Most metals you use are actually alloys - mixtures that improve properties. Pure metals are rarely strong enough alone. Understanding material properties like ductility (stretches without breaking), malleability (shapes without cracking), and tensile strength (resists breaking under tension) helps you pick the right metal for each job.
Key Point: Remember the iron rule - ferrous = iron = magnetic = rusts. Non-ferrous = no iron = non-magnetic = better corrosion resistance!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Your clothes tell an amazing story of global materials! Natural fibres come from plants (cotton, bamboo, linen) or animals (wool, silk), whilst synthetic fibres are oil-based polymers, and regenerated fibres recycle existing materials.
Natural fibres each have distinct personalities. Cotton from China and the USA is cool, cheap, and strong - perfect for jeans and shirts. Wool from UK sheep and Australian farms is soft, hardwearing, and naturally renewable. Silk from Chinese moth cocoons is expensive but drapes beautifully with brilliant insulation properties.
Synthetic fibres solve natural fibre problems. Polyester is cheap, durable, and doesn't wrinkle - ideal for school uniforms. Acrylic mimics wool's warmth without the cost. These polymers are extracted from oil and forced through tiny holes to create continuous filaments.
Blended fabrics give you the best of both worlds. Polycotton combines polyester's durability with cotton's comfort. Kevlar uses chemical bonds and clever weaving to become five times stronger than steel. Modern technical fabrics like Sympatex are both breathable and waterproof - perfect for serious sportswear.
Pro Tip: Fabric denier measures thickness - 30 denier tights are thin and delicate, 100 denier are thick and robust!
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.
5
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
App 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
Physics
Sociology