Aluminium and its alloys are used in aircraft construction because they have strength and low density. Duralumin Not all exam boards require this. Duralumin is a much stronger alloy of aluminium containing copper and magnesium. The tutorial gives a different account depending on your syllabus details . Gold is not affected by the air and silver is only tarnished on the surface by sulphur compounds in the air.
Copper turns from pink to brown in air.
CuCO 3 Metals high in the reactivity series corrode very quickly in air. Potassium and sodium are kept under paraffin to prevent reaction with the air. The corrosion of metals between calcium and copper depends on the properties of the metal oxide. Aluminium oxide has a coating that prevents further reaction with the air. Removing this coating makes aluminium behave according to its position in the series.