What is the formula for a molecule containing three calcium atoms (ca) and three chlorine atoms
(ci)?
o3caci
cacla
cazcl3
o ca₃cl3

3CaCl2

calcium has 2 electrons to get rid of and chlorine has 1 electron to fill

Big 3 infront of Ca and small 2 behind Cl

since you're a real machine, your ama is always less than your ima, because you can never totally eliminate friction.

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 =