1. CO 2. SO ₂ 3. CO ₂ 4. O ₃

Which of the following is a secondary pollutant ?

1. CO

2. SO\(_2\)

3. CO\(_2\)

4. O\(_3\)

Doubtly Asked 30 Oct 2026 NEET UG 2018 neet Save WhatsApp Report

Best answer

Answer: 4. O\(_3\)

A secondary pollutant is formed in the air by reactions of primary pollutants; ozone is formed from NO\(_x\) and hydrocarbons in sunlight.

CO, SO\(_2\) and CO\(_2\) are released directly, so they are primary pollutants.

Doubtly AI · 30 Oct 2026 AI-generated · not yet verified Report

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