To determine the number of helium atoms present in a given mass of helium, we first convert the mass into number of moles by dividing the atomic mass of helium which is 4 grams per mole. Then, we multiply the Avogadro's number which represents the number of
units in one mole of any substance. This has the value of 6.022 x 10^23 units /
mole. We do as follows:
537 kg He ( 1000 g / 1 kg ) ( 1 mol / 4 g ) ( 6.022 x 10^23 atom / mol ) = 8.08x10^28 atoms He
