The physicals properties of a substance can be used to identify the substance, because. Select all that apply. each substance has a unique set of physical properties
no two substances have any of the same properties
when the substances are chemically reacted the physical properties remain the same
at any given location, the physical properties of a substance do not change

each substance has a unique set of physical properties

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 =