Which of the following are classified as secondary air pollutants? 1. Tropospheric Ozone (O₃) 2. Sulfur dioxide (SO₂) 3. Ammonium Sulphate 4. Photochemical Smog 5. Carbon monoxide (CO) Select the correct answer using the code given below: |ForumIAS

[A] 1, 2 and 3 only

[B] 1, 3 and 4 only

[C] 2, 4 and 5 only

[D] 1, 2, 3 and 5 only

Answer: B

Notes:

Explanation:

Tropospheric Ozone (O₃) –Secondary pollutant, formed by reactions involving NOx and VOCs in the presence of sunlight.
Sulfur Dioxide (SO₂) –Primary pollutant, emitted directly from sources like coal combustion.
Ammonium Sulphate – Secondary pollutant, formed from SO₂ and NH₃ reacting in the atmosphere.
Photochemical Smog – Secondary pollutant, formed through sunlight-driven reactions involving NOx and VOCs.
Carbon Monoxide (CO) – Primary pollutant, emitted directly from incomplete combustion.

Source: Environment (N.C.E.R.T)