Which of the following are primary aerosols in the atmosphere?

1.Sea salt

2.Black carbon

3.Sulphate

4.Nitrate

5.Mineral particles

A1, 2 & 3 only

B2, 3 & 4 only

C1, 2 & 5 only ✓ Correct

D3, 4 & 5 only

Correct answer: (C) 1, 2 & 5 only

Explanation

Primary aerosols are emitted directly into the air as particles, while secondary ones form there by chemical reaction.

Statement 1: sea salt is thrown up directly from ocean spray, a primary aerosol.

Statement 2: black carbon or soot comes straight from incomplete combustion, a primary aerosol.

Statement 5: mineral particles are lifted directly as wind-blown dust, a primary aerosol.

Statement 3 and Statement 4: sulphate and nitrate form in the air from gases like sulphur dioxide and nitrogen oxides, so they are secondary.

Fine aerosols scatter sunlight and act as cloud condensation nuclei, influencing climate.

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