Question

Which of the following is secondary pollutant?

विकल्प

• NO

• NO₂

• SO₂

• PAN

Answer 1

PAN

Explanation:

Peroxyacetyl nitrate (PAN) forms in the atmosphere through photochemical reactions and is a secondary pollutant. NO and SO₂ are primary pollutants; the supplied answer key identifies PAN as the correct choice.