there are about 10^23 atoms in a mole of material, that is a quantity in grams equivalent to the atomic weight of that material. The earth diameter is 10^7 m, by definition, so the radius is about the same order of magnitude, and the volume is roughly 10^21 m^3. Assuming a density of 10 and an atomic number of 100 (I am making up these numbers, but they are not so far from reality) it means 10^20 moles of material, therefore 10^43 atoms. Of course, just a rough estimate, but not so far from reality
Comments