(a) Fossil fuels like coal and petroleum contain small amount of sulphur and nitrogen. As they are burnt oxides of nitrogen and sulphur are formed along with the oxides of carbon. These causes inhalation problems.

(b) These gases are also responsible for causing acid rain.

(c) Burning of fossil fuels release suspended particles in the air. These particles reduce visibility.

OR

The sun heats up rocks during the day as a result they expand. But at night, these rocks cool down and contract. Since all parts of the rock do not expand and contract at the same rate, this results in the formation of cracks and ultimately the rocks breaks up into smaller pieces. These small pieces further break into still smaller pieces and fine particles. Thus, the soil is formed.