# What is O2 and O3?

${O}_{2}$ is the oxygen you are breathing now, and comprises some 20.95% of the atmosphere..........
..........under exceptional circumstances, oxygen can exist as the ozone molecule, ${O}_{3}$, a bent molecule whose Lewis structure we would represent as ""^(-)O-O^(+)=O. This site reports that ozone comprises $\text{0.6 ppm}$ of the atmosphere.