State what is meant by the term 'atmospheric pollution'. Name four gaseous atmospheric pollutants.

Explain the term 'acid rain'. State the two forms of deposition of acid rain with suitable examples of each form of deposition.

Burning of fossil fuels is an important source of the pollutant – 'oxides of sulphur' responsible for acid rain. State what are 'fossil fuels'. Name the principal fossil fuels. State why sulphur dioxide is emitted on burning a fossil fuel. Give a balanced equation for the same.

During metallurgy – smelting plants produce sulphur dioxide, when metallic sulphides are roasted in air. Give a balanced equation for the same.