<prompt> Not a constituent of airH2N2O2CO2  <response>: Air The immediate environment of man comprises of air on which depends all forms of life.The requirement for air is about 10-20 M3day.The constituents of air : -Major Nitrogen N2 - 78.1 , Oxygen O2 - 20.93, Carbon dioxide CO2 - 0.03Minor Argon, neon, krypton, xenon, helium, water vapour, traces fo ammonia, suspended matter dust, bacteria, spores, vegetable debris. 