Given that, Density of surface site = 6.023 x 10^{14} cm^{-2}

Total surface area = 1000 cm^{2}

Total number of surface sites = density x total surface area

= 6.023 x 10^{14} x 1000

= 6.023 x 10^{17}

Sites occupied by nitrogen molecule (20%)

0

Therefore, number of sites occupied by each nitrogen molecules