What energy change would accompany the loss of 0.1 mg in mass? express the energy change in kilojoules to one significant digit.

9 x 10^6 J

Explanation:

mass, m = 0.1 mg = 0.1 x 10^-6 kg

According to the mass energy equivalence

E = mc²

where, c is the velocity of light

c = 3 x 10^8 m/s

E = 0.1 x 10^-6 x 3 x 10^8 x 3 x 10^8

E = 9 x 10^9 J

E = 9 x 10^6 kJ

Thus, the energy is 9 x 10^6 J.

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 =