This video explains how to find number of atoms from given mole.
Mole is the unit used to express quantity of a substance in terms of number of atoms or molecules.
Molecular mass is the sum of atomic mass
Mass % = Mass of an element/Molar Mass
To find mass from moles, Use the given formula
Number of moles= Given mass/ Molar mass
Number of moles= number of particles/Avogadro consta