The planetary model of the atom pictures electrons orbiting the atomic nucleus much as planets orbit the sun. in this model you can view hydrogen, the simplest atom, as having a single electron in a circular orbit 1.06×10−10m in diameter. (a) if the average speed of the electron in this orbit is known to be 2.20×106m/s, calculate the number of revolutions per second it makes about the nucleus. (b) what is the electron's average velocity

energy can be converted from one form to another, but it cannot be created or destroyed in ordinary chemical or physical means. do not understand what you are asking but 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 =