9E-making materials Flashcards
(30 cards)
Why do different materials have different properties?
The particles (or atoms) within the material are arranged in different ways so have different strengths forces of attraction between them
why is a metal dense?
the metal particles (or atoms) are held very closely together by strong forces of attraction
what does porous mean?
a porous material has lots of gaps in the structure that will allow water to flow through it.
why do metals have high melting points?
The metal particles (or atoms) are held very closely together by strong forces of attraction. It takes a lot of energy to break them, so that’s why metals have a high melting point..
what is a composite material?
A combination of two or more materials with some of the properties of each
Name 3 composite materials?
Concrete, GRP,Kevlar,composite,safety glass
Name 3 ceramics?
Glass, China, Ceramics,Porcelain
State 3 common properties of ceramics?
Hard, High melting points, good insulators of heat and electricity, very unreactive, heat resistant
what is a lattice structure?
a large number of atoms all join together in a regular pattern
why are ceramics strong?
The atoms arrange themselves into a rigid lattice structure
What would you expect to see in crystals that have been cooled in slowly?
Larger crystals
What is a polymer?
A compound made by joining lots of small monomer molecules together
Name 3 polymers?
Rubber, PVC, Polythene,nylon,PVC
What molecular structure would you see in a polymer?
A long chain made up of repeated groups of atoms
What does exothermic mean?
Transfers energy to the surrounding
How do we make polymers stronger and less flexible?
Attach long polymer chains together by cross-linking them. This is called vulcanisation
Why do you vulcanise rubber?
To make it harder and tougher, and stop its properties from changing with temperature
State 3 common properties of polymers?
Usually insulators, are flexible, are light and can be moulded.
What is natural rubber plastic?
When the material is heated the molecules slide over each other but do not go back to the original shape after they have been stretched and cooled.
Why is vulcanised rubber elastic?
The molecules can’t slide over each other, so the material returns to its original shape after it has been stretched.
what is a finite resource?
a resource with a limited supply that will eventually run out.
What are most plastics made from?
chemicals that come from oil, gas or coal.
what is recycling?
The process of converting waste materials that would normally be thrown away into new materials and objects.
State 3 advantages of recycling?
1) reduce the amount of waste sent to landfill sights.
2) Conserves natural resources such as fossil fuels.
3) May use less energy than producing new products from raw materials
