Moles equation is moles= mass/RFM Avogadro's constant is 6.x 1023.
1 mole means 6x 1023 atoms/molecules.
e.g. 2 mole of Cu weighs 128g. What is the weight of 1 Cu atom?
2 moles is 2x 6x1023 atoms = 1.2x1024 atoms=128g
therefore 128/1.2x1024= weight of 1 atom= 1x 10-22g