Q1. Which of the following statements is true about ozone?
A Conversion of ozone to oxygen is an endothermic reaction.
B Ozone is a triatomic linear molecule.
C Ozone has two double bonds.
D Low-level ozone, or tropospheric ozone, is an atmospheric pollutant. Correct
Explanation
Low-level ozone in the troposphere is a harmful air pollutant and a major component of photochemical smog, so that statement is true. The conversion of ozone to oxygen releases energy; it is not an endothermic change. Ozone is triatomic, but its molecule is bent, not linear. Its bonding is described by resonance, with equivalent oxygen-oxygen bonds, not by a simple structure having two fixed double bonds. The correct statement is therefore the one about tropospheric ozone as an atmospheric pollutant.