Question

A primary air pollutant is?
(A) $C{H_4}$
(B) ${H_2}S$
(C) \[CO\]
(D) All of the above

Answer 1

Hint:-Air is a homogeneous mixture of various gases present in different proportions. The components of air include oxygen, nitrogen, carbon dioxide, and water vapours. Nitrogen consist of $78\% $ air, oxygen is present in $21\% $and the rest contains noble gases, carbon dioxide, and water vapours in small proportions.

Complete Answer:-
When there is a presence of a substance in the air that can be harmful to living beings including humans, and can cause damage, it is called Air Pollution. The substances that pollute the air are called pollutants and these can be gases, particulates, and biological molecules.

When the pollutants that are emitted directly into the air, are called primary air pollutants. Examples include Sulphur dioxide, Carbon monoxide, Lead, Ammonia, Volatile organic matter like Benzene and Methane. They can have a direct effect or indirect effect by acting as precursors of secondary air pollutants. A secondary air pollutant does not directly emit into the air but is formed in the air by a combination of primary air pollutants in the atmosphere. Examples include Ozone, which is formed by the combination of hydrocarbons and nitrogen oxides in the presence of the atmosphere.

So, all the options given in the questions are primary air pollutants. Hence the correct answer is Option (D), All of the above.

Note:- Acid rain which is responsible for the damage to the Taj Mahal is a secondary air pollutant formed from the combination of sulfur dioxide or nitrogen oxides with water. It corroded metals, marbles, and stones. It can be minimized by reducing fuel emission from cars and avoiding the burning of woods.