Question

How many moles of helium are in a balloon filled with 6.02 x 1025 atoms of helium?

Answer 1

There are 6.02x10^23 atoms per every mole of substance. Mathematically, we can write: \[\frac{6.02 *10^{23} \ atoms}{1 \ mol}\] So if we divide the amount of atoms we have by this amount we'll have the number of moles since the units of atoms will cancel out.

Answer 2

(6.02*10^25)/(6.03*10^23)= number of moles of He
since you are given particles you divide using Avogrados number