The lanthanides are all radioactive true or false

False

Explanation:

All the lanthanides are not radioactive in nature. Just one of the lanthanides are radioactive.

a person with a mass of 106kg has a weight of 1060n

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 =