Metals in the Earth's crust

— metals are found in the Earth's crust

• compounds
• native = elemental form → unreactive metals

The composition of metals in the Earth's crust

• oxygen → 45%

• silicon → 27%

  — non-metals

  — exists as compounds → oxides

• aluminium → 8%

• iron → 6%

• calcium → 5%

• magnesium → 3%

• sodium → 2.5%

• potassium → 1.5

• others → 2%

— precious metals → gold, silver, platinum, palladium → expensive, scarce

— rocks from the Earth's crust contain compounds

— rocks from which metals are extracted are called ores

• contains metals or compounds

e.g.

• rock salt → sodium chloride