Assuming the human body is primarily made of water, estimate the number of molecules in it. (Note that water has a molecular mass of 18 g/mol and there are roughly 1024 atoms in a mole)

The 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 25.0°C? molecules (b) If the molar mass of air is 28.96 g/mol, what is the mass (in g) of air molecules inhaled with each breath? (Assume the air temperature is 25.0°C.) g (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 (in kg) of the air in Earth's atmosphere? (Assume the density of air used in this calculation was 1.225 kg/m³.) kg (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 25.0°C everywhere on Earth.) %

Estimate the number of people in the world who are suffering from the common cold on any given day. (Remember that a person suffers from a cold for about a week, and assume that the average person catches a cold twice a year. The population of Earth is approximately seven billion.) O 10² O 105 O 108 O 10¹3