This is a good example of homogeneous catalysis where everything is present as a gas.
Ozone, O3, is constantly being formed and broken up again in the high atmosphere by the action of ultraviolet light. Ordinary oxygen molecules absorb ultraviolet light and break into individual oxygen atoms. These have unpaired electrons, and are known as free radicals. They are very reactive.
You have to use Avogadro's number which is 6.02x10^23. The units of Avogadro's number is molecules/mole so you divide the number of molecules by Avogadro's number which will give you the number of moles. (2.0x10^22 molecules)/(6.02x10^23 molecules/mole)=0.033 moles
