Multiple choice

Which of the following is always present in photochemical smog?

  1. O3

  2. CH4

  3. SO2

  4. CO2

  5. -

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Photochemical smog is haze in the atmosphere that is accompanied by high levels of ozone and nitrogen oxides. It is caused by the action of sunlight on pollutants.