1. If air contains " 78% nitrogen"... what else does this mean? A. 78 grams of N2 in 100 grams of air B. The mole fraction of N2 in air is 0.78 C. The partial pressure of N2 is 78atm D. 78 molecules of N2 in 1cm3 of air E. Only inhale from 21% of the left side of your mouth to get the oxygen 2. If the total air pressure is 1atm, what is the partial pressure of nitrogen? A. 0.78kPa B. 78atm C. 7.8atm D. 0.78atm 3. A 3 ppb of ozone means... A. 3 molecules of ozone in 1,000,000 molecules of air B. 3 grams of ozone in 1,000,000,000 molecules of air C. 3 grams of ozone in 1,000,000,000 grams of air D. 3 volumes of ozone in 1,000,000,000 volumes of air E. 3 molecules of ozone in 1,000,000,000 molecules of air 4. The primary air quality standard for NO2 in the united states, expressed as annual average, is 53ppb, what is the equivalent concentration in g/m3