Question

Which of the following is a Secondary Pollutant?

• A. ${\mathrm{CO}}_2$
• B. ${\mathrm{SO}}_2$
• C. ${\mathrm{O}}_3$
• D. $\mathrm{CO}$

Answer 1

The correct option is C

${\mathrm{O}}_3$

Primary Pollutants: Pollutants that are emitted into the environment from a source(like vehicles and factories) are called primary pollutants.

Example: CO_2,SO_2,CO etc.

Secondary pollutants: Secondary pollutants are pollutants that form in the atmosphere. These pollutants are not emitted directly from a source (like vehicles or power plants). They form as a result of the pollutants emitted from these sources reacting with molecules in the atmosphere to form a new pollutant.

Ozone (O₃) is a secondary pollutant that is formed by the interaction of primary air pollutants.

Hence, Option (C) is correct.