How many atoms are present in 65.39 g of zinc?

Avogadro's number represents the number of units in one mole of any substance. This has the value of 6.022 x 10^23 units / mole. This number can be used to convert the number of atoms or molecules into number of moles.

65.39 g Zn (1 mol / 65.38 g) (6.022 x 10^23 atoms / 1 mol) = 6.023x10^23 atoms Zn