Metals and their Uses Flashcards
What is a metal ore?
A rock which contains enough metal to make it profitable to extract the metal from it.
What is a common metal ore of aluminium?
Bauxite
How do you extract a metal from its ore if the metal is less reactive than carbon?
React it with carbon to make metal and carbon dioxide. This is called reduction.
How do you extract a metal from its ore if the metal is more reactive than carbon?
Electrolysis
How can copper be removed from its ore?
You can hear it in a furnace. This is called smelting.
What is the problem with copper from smelting?
It is impure.
How can we purify copper?
Electrolysis
What is electrolysis
The breaking down of a substance using electricity.
What is an electrolyte?
A liquid containing free ions that can conduct electricity. It is an important part of electrolysis.
What ions must be in the electrolyte when performing electrolysis?
The ions of the metal you are trying to gain.
Describe the electrolysis of copper.
1) The annode is a lump of impure copper.
2) When the current is switched on, the positive copper ions in the electrolyte begin to move towards the cathode and are replaced by more ions from the annode.
3) The ions that get to the cathode are reduced - they gain electrons to become atoms.
4) The impurities in the copper don’t lose their electrons as easily so are left as sludge underneath the annode.
5) The annode slowly disappears.
What is a low grade ore?
An ore with too little copper to make it viable to extract it using traditional methods.
What is bioleaching?
When bacteria separate copper from copper sulphate. The bacteria get energy from the breaking of the bonds and leave behind leachate with can be filtered to get copper.
What is phytomining?
Plants are grown on copper-rich soil. The copper builds up in the leaves as it serves no purpose to the plants so they are dried and burned. The ash produced contains pure copper.
What are two advantages of bioleaching and phytomining?
They are cheaper and better for the environment.
What is a disadvantage of bioleaching and phytomining?
They are very slow.
What is displacement?
When a more reactive metal is added to a solution of a less reactive metal compound to replace it. Iron is often used to displace copper from copper sulphate.
What are three benefits of extracting metals?
- Create useful products
- Creates jobs
- Brings money to local area
What are five disadvantages of extracting metals?
- Noise pollution
- Traffic
- Habitat destruction
- Visual pollution
- Requires a lot of energy
Give four reasons why it is important to recycle metals.
- Recycling metal only takes 15% of the energy required to obtain new metal
- Saves money
- Conserves our finite metal supplies
- Reduces waste
What are three common properties of metals?
- Strong
- Malleable
- Good conductors
What are the three key properties of copper?
- Good conductor
- Hard yet malleable
- Doesn’t react with water
What are the three key properties of aluminium?
- Corrosion-resistant
- Lightweight
- Not strong by itself
What are the three key properties of titanium?
- Lightweight
- Very strong
- Corrosion resistant
What are alloys?
Mixtures of two or more metals or of a metal and a non-metal.
Why are alloys harder than metals?
Because the different sized atoms disrupt the regular structure making the layers less likely to slide past each other.
What is bronze?
An alloy of copper and tin used for medals and statues.
What is cupronickel?
An alloy of copper and nickel used in silver coins.
What are good alloys?
Strengthened forms of gold used in jewellery.
What are aluminium alloys?
Strengthened forms of aluminium used for aircraft production.
What percentage iron is iron from the furnace?
96%
What do we call iron straight from the furnace?
Cast iron
What are the properties of cast iron?
- Malleable
* Brittle
What is low-carbon steel?
Iron with some carbon. It is easily shaped and used in car bodies.
What is high-carbon steel?
Iron with carbon. It is very hard and used for cutting tools and bridges.
What is stainless steel?
Corrosion resistant steel. Used for cutlery.
