Five gases combined in a gas cylinder have the following partial pressures: 3.00 atm (n2), 1.80 atm (o2), 0.29 atm (ar), 0.18 atm (he), and 0.10 atm (h). what is the total pressure that is exerted by the gases?
a. 5.08 atm
b. 5.19 atm
c. 5.27 atm
d. 5.37 atm

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =

it is b. absorbs thermal energy