Assertion. Ozone layer is a sort of sunscreen present high up in the atmosphere which prevents the harmful ultra-violet rays of the sun from harming us.

Reason. Ozone is an allotropic form of carbon which is formed in the atmosphere due to the release of chloroflurocarbons.

1. Both A and R are True
2. Both A and R are False
3. A is True and R is False.
4. A is False and R is True.

Assertion. The greenhouse effect is exacerbated by the presence of nitrogen oxides and sulphur oxides in the atmosphere, intensifying the absorption of heat and contributing to global warming.

Reason. Oxides of nitrogen and sulphur, primarily released through industrial activities and combustion processes, amplify the greenhouse effect by enhancing the heat-trapping capacities of the atmosphere, leading to an increase in the average global temperatures.

1. Both A and R are True
2. Both A and R are False
3. A is True and R is False.
4. A is False and R is True.

Match the items in column I with the closely related ones in column II.

Fill in the blanks:

(i) Rubber particles and dust raised by running motor vehicles are examples of …………… pollutants.

(ii) Too frequent exposure to …………… in a medical diagnostic technique may damage chromosomes.

(iii) Thermal power plants give out a lot of …………… waste water.

(iv) Sewage is a liquid waste from ……………