Air Pollutant
A substance that is not usually found in the air or it is present in abundance. 

Composition of unpolluted air:
n78% Nitrogen
n21% Oxygen
n1%  Argon
n0.03% Carbon dioxide
nTrace amounts of other gases +4%water vapour

Primary air pollutants:
nCarbon monoxide(CO)
nOxides of nitrogen(NOx):N2O, NO, NO2
nOxides of sulfur(SO2) and SO3(oxidation of SO2)
nParticulates
nHydrocarbons and volatile organic compounds



IB Practice Problem: