metals and their uses

alloys

• iron from blast furnace contains 96% iron
  - impurities make it brittle -> limited uses
• most iron is converted into steel
  - steel is an alloy - mixture of iron with carbon
  - alloys can be designed to have properties for specific uses
  - low carbon steels are easily shaped, high carbon steels are hard and stainless steels are resistant to corrosion
• pure copper, gold, iron and aluminium are too soft for everyday use so are mixed with other metals to make them harder 

extracting metals

• ores contain enough metal to make it economical to extract the metal
• ores are mined and may be concentrated before the metal is extracted and purified
• unreactive metals i.e. gold are found in the earth as the metal itself but most are found as compounds that require chemical reactions to extract the metal
• metals less reactive than carbon can be extracted from their oxides by reduction (removal of oxygen)
  - carbon can only take the oxygen away from metals which are less reactive than carbon itself
• metals more…