Gthe tidal lung volume of human breathing, representing the amount of air inhaled and exhaled in a normal breath, is 500 cm3. (assume atmospheric pressure.) (a) what is the number of molecules of air inhaled with each human breath when the air temperature is 19.0°c? molecules (b) if the molar mass of air is 28.96 g/mol, what is the mass of air molecules inhaled with each breath? (assume the air temperature is 19.0°c.) (c) it has been calculated that all of the air in earth's atmosphere could be collected into a sphere of diameter 1,999 km at a pressure of 1.00 atm. what is the mass of the air in earth's atmosphere? (assume the density of air used in this calculation was 1.225 kg/m3.) (d) if all 7 billion humans on earth inhaled simultaneously, what percentage of the atmosphere would be inhaled during this process? (assume the air temperature is 19.0°c everywhere on earth.)