### How many atoms do mercury vapor molecules consist of if the density of mercury vapor relative to air is 6.92The average mass of air is 29gmole?

29g air=1mole 29g of air corresponds to 22.4l of air therefoe 1litre of air=29/22.4=1.3 relative density=6.92 therefore 6.92*1.3=Density of mercury=8.96g/l 8.96g of Hg vapour corresponds to 1 litre of mercury therefore 8.96*22.4g of mercury vapour corresponds to 1 mole of mercury therefore 200g of mercury vapour corresponds to 1 mole of mercury at wt of mercury =200 therefore mercury vapour contains 1 atom of mercury