C2 - Construction Materials & Metals, Alloys & Making cars Flashcards
Where do many construction materials come from?
Rocks found in the Earth’s crust
What are the rocks called that metals such as iron and aluminium are extracted from called?
Ores
How is brick made?
By baking clay that has been extracted from the Earth
What are glass, concrete and cement all made from?
Sand (small grains of rock)
Why is limestone the easiest rock to shape?
Because it’s the softest
Which rock is the hardest to shape?
Granite
What type of rock is limestone?
Sedimentary
What type of rock is marble?
Metamorphic
What type of rock is granite?
Igneous
What are limestone and marble mainly made of?
Calcium carbonate ( CaCO₃)
When calcium carbonate is heated, what does it break down into?
Calcium oxide and carbon dioxide
When one material breaks down into two or more substances when heated, what is this called?
A thermal decomposition reaction
How is cement made?
By heating clay and limestone together
What is a composite material?
That which combines the best properties of each component material.
Give an example of a composite material
Reinforced concrete
What properties does reinforced concrete combine?
The strength and flexibility of the steel bars with the hardness of the concrete.
How is copper extracted from naturally occurring copper ore?
By heating it with carbon
Copper ore is called copper oxide. When copper is extracted, the oxygen is removed from the copper oxide. What is this process called?
Reduction
If copper is very impure, what must happen before it can be used again?
Electrolysis
What happens in electrolysis?
Electricity is passed through a liquid or a solution called an electrolyte, e.g. copper(II) sulfate solution, to make simpler substances.
What is the positive electrode in electrolysis called?
The anode
What is the negative electrode in electrolysis called?
The cathode
What is the anode in electrolysis made of?
Impure copper
What is the cathode in electrolysis made of?
Pure copper
When electrons are lost, what is this called?
An oxidation process
When electrons are gained, what is this called?
A reduction process
What is an alloy?
A mixture of a metal with another element
Give three examples of alloys
Bronze, steel, amalgam, solder, brass
What is amalgam made using?
Mercury
What is solder made using?
Lead and tin
What is brass made using?
Copper and zinc
What is a smart alloy?
It can be bent and twisted, and will return to its original shape when heated
Give an example of a smart alloy, and what it is an alloy of.
Nitinol (an alloy of nickel and titanium)
Why is nylon fibre used to make seat belts?
Because it’s strong and flexible
Why is glass used to make windscreens?
Because it’s transparent
Why is copper used for wiring?
because it’s a good electrical conductor
Why is plastic used for the trim on cars?
Because it’s rigid and doesn’t corrode
Why is steel used to make the body of a car?
Because it is strong and malleable
Why is aluminium used to make they alloy wheels on a car?
Because it is lightweight and doesn’t corrode in moist conditions
Why will a car made from aluminium have better fuel economy?
Because it is lighter
Why will a car made from aluminium have a longer lifetime?
Because it doesn’t corrode
What is an oxidation reaction?
A reaction where oxygen is added to a substance
Give an example of an oxidation reaction
Rusting
What three things does rusting need?
Iron, water and oxygen (air)
Aluminium doesn’t react and corrode in air and water. What does it do instead?
It quickly forms a protective layer of aluminium oxide.
What are some benefits of recycling materials?
Less quarrying is needed, less energy is used to extract them from ores, the limited ore reserves will last longer, recycling plastics and fibres reduces the amount of crude oil needed to make them, conserves reserves, and disposal problems are reduced
When iron atoms are changed into iron(III) ions, what is this process called and why?
Oxidation, because electrons are lost
