metals

metal extraction:

• an ore is a rock containing enough metal to make it economically viable to extract from the compound 
• most chemicals need to be exracted from their ores using a chemical reaction 
• in many cases the ore is an oxide of the metal, you can exract most metals by using reduction  with carbon which is the removal of oxygen from a compound.
• you can use smelting to extract a metal, this method heats an ore using charcoal to extract the metal this is another term for reduction using carbon 
• displacement is a reaction where a more reative metal will move a less reactive metal from its compound 
• there are a few metals which are found in the earth as the metal itself like gold, rather than a compound. 
• the posistion of the metal determines whether or not they will be extracted by reduction with carbon

ELECTROLYSIS:

• electrolysis is the breaking down of of substance using electricity, it requires a liquid to conduct the electricity this is called an electrolyte they are often molten metal oxides or metal salt solutions from the ore
• the electrode has free ions these conduct the electricty and allow everything to work 
• electrons are taken away by the (poistive) anode and are given away by the (negative) cathode as ions gain or lose electrons they become atoms or moelecules and are released
• electrolysis is used to get copper by having electrons which are pulled off copper atom at an anode, which causes them to go into the solusion as Cu2 ions
• Cu2 ions near the cathode gain negative elecrons and turn back intp copper atoms
• the impurities are dropped at the anode as sludge whilst pure copper atoms bond to the cathode

• metals higher than carbon have to be extracted using elelcroylsis of molten compunds which is expensive
• metals below carbon can be extracted from their ores using reduction with carbon, for example iron dioxide is put into a blast furnace to make just iron. 
• carbon can only take the oxygen away from metals if they are less reative than itself is.
• electrolysis is a lot more expensive that reduction using carbon becuase it uses a lot more energy 
• for example: a high temperature is needed to melt aluminium oxide so that the aluminium can be extracted, this requires lots of energy which makes it very expensive
• copper can be exracted easily by reduction by carbon in a blast furnace using smelting 
• however the copper produced this way is impure, which doesnt conduct electricity very well, it isnt very useful like this because most copper is used to make electrical wiring 
• so electrolysis is used to purify the coppper even though its quite…