Using Resources Flashcards
What is a ceramic?
Non-metal solids with high melting points that aren’t made from carbon based compounds
What are too examples of ceramics?
Clay
Glass
What are composites made of?
Made of one material embedded in another, fibre or fragments are surrounded by a matrix acting as an binder
What are the two things that can influence the properties of a polymer?
How it’s made
What it’s made from
How is low density polyethene made?
Moderate temperature
High pressure
Catalyst
How is high density polyethene made?
Lower temperature
Lower pressure
Different catalyst
What do the monomer determine?
Type of bonds that form between the polymer chains
What do thermosetting polymers contain and why is this useful?
Monomers that contain cross links between the chains so it is a solid structure and don’t soften when heated
What do thermosoftening polymers contain?
Individual chains entwined together with weak forces so they melt when heated and can be remoulded
What are the properties of ceramics?
Insulators of heat and electricity
Brittle
Stiff
What are the properties of polymers?
Insulators of heat and electricity
Flexible
Easily moulded
What are the properties of metals?
Malleable Good conductor of heat and electricity Ductile Shiny Stiff
What do the properties of composites depend on?
Matrix/binder
Reinforcement
What are the uses and properties of low carbon steel?
Easily shaped
Car bodies
What are the uses and properties of high carbon steel?
Very hard
Flexible
Blades for cutting tools
Bridges
What are the uses and properties stainless steel?
Corrosive resistant
Cutlery
Containers for corrosive substances
What is bronze made from?
Copper and tin
What is a property of bronze?
Hard
What is bronze used for?
Medals
Decorative ornaments
Statues
What is brass made from?
Copper and zinc
What is a property of brass?
Malleable
What is brass used for?
Water taps
Door fittings
What metals are used to harden gold?
Zinc
Copper
Silver
Why is gold alloys used to make jewellery?
Pure gold is very soft
Why is aluminium alloys used to make aircraft?
Low density but pure aluminium is too soft
What metal corrodes easily?
Iron
What is the compound for rust?
Hydrated iron (III) oxide
What is the equation for corrosion?
Iron + oxygen + water —–> hydrated iron (III) oxide
Why isn’t aluminium completely destroyed by corrosion?
Aluminium oxide that forms doesn’t flake away but acts as a protective layer, preventing further corrosion
What way can you show that water alone isn’t enough to cause corrosion?
Iron nail in a boiling tube with water
Water is boiled to remove oxygen
Layer of oil to stop oxygen getting in
What way can you show that oxygen alone isn’t enough to cause corrosion?
Iron nail in a boiling tube
With calcium chloride to absorb any water
What is electroplating?
Using electrolysis to reduce metal ions onto an iron electrode
Coat the iron with a layer of different metal that won/t corrode
What is painting/coating with plastic?
Protecting it with paint/plastics to prevent further corrosion
What is oiling/greasing?
Putting oil/grease on moving parts of vehicles
What is the sacrificial method?
Placing a more reactive metal such as zinc with iron so water and oxygen will react with zinc
What is it called when an object is sprayed with a coating of zinc?
Galvanising