In the formation of the compound magnesium oxide (Mgo), A
a magnesium atom donates two electrons to an oxygen atom.
B
an oxygen atom shares one electron with a magnesium atom.
С
a magnesium atom shares two electrons with an oxygen atom.
D
an oxygen atom donates one electrons to a magnesium atom.

i would like to make dinner for my mom, dad, and sister

the rearrangement of particles in a physical change. hope this

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 =