Question

Give a geographical reason:

Oxidation changes the size and colour of the rocks.

Answer 1

Oxidation changes the size and colour of the rocks because -

• Oxygen in the air and water reacts with certain elements in the minerals inside the rock.
• In this process, the minerals in the rock react with the oxygen present in the air or water.
• Metals, particularly iron and aluminium, commonly oxidize forming iron or aluminium oxides. It is also called rusting. 
• These oxides are larger in volume than in the original rocks. 
• The iron oxides are red in colour and aluminium oxides are yellow. 
• Thus, oxidation changes the size and colour of the rock.