(i) Justify ‘Dust is a pollutant.’
(ii) Explain the role of the sun in the formation of the soil.
(iii) Carbon dioxide is necessary for plants, why do we consider it as a pollutant.

Hint: Dust is fine particles of dirt that go through the air. They can be made up of a number of different substances like dead skin and even soil. Soil is made up of organic matter and minerals that come from broken-down rocks. The sun helps to break down rocks. Carbon dioxide is used by plants to make their food however in excess it can be harmful to the planet.

Complete answer:
i) Dust has a fine texture that allows it to easily float on air. In large quantities, these fine particles can cover the leaves of plants and block them from sunlight. The dust also blocks the stomata on the underside of the leaves which doesn’t allow the plant to get rid of its waste. It is known to be an allergen that can cause many respiratory issues.
ii) Soil is made up of a variety of materials including organic matter and minerals. Some of the minerals in the soil come from rocks. Rocks are usually made up of solidified minerals and thus they are very hard. The sun heats these rocks up and therefore causes the rocks to expand. Once the sun is gone, the rocks cool down and contract. Over time the expansion and contraction of the rocks lead to them cracking and breaking up into soil.
iii) Carbon dioxide is one of the main greenhouse gases. In large quantities, carbon dioxide is responsible for trapping infrared rays from the sun. This heats up the planet and leads to global warming. This is why carbon dioxide is a major pollutant.

Note:
This fine texture of dust makes it easy to inhale. This builds up in the lungs and causes respiratory issues. Although the heat of the sun can be helpful, if too much heat gets trapped it leads to climate change.