How many atoms are in Earth?

Question

I got a question. How many atoms are in the Earth if the Earth has a mass of 5.98*10^24 kg.? It says the average mass of the atoms that make up the Earth is about 39 u. U is the atomic mass unit.

Answer 1

Well, if the average mass of a single atom on Earth is 39 amu, and there are 1.66053886*10^-24 grams in a single amu, then the average mass of a atom is 6.47610155*10^-23 grams. Divide Earth's mass of 5.98*10^24 kg by the average atomic mass and we get 9.23395032*10^46 atoms on Earth.