Relationship between moles and Avogadro's constant

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