is calculating the number of molecules the same method as calculating the number of atoms?

Question

like is calculating the number of molecules in 288g of Cl2 the same as calculating the number of atoms in 23g of Na

Answer 1

Yes. For molecules, use the molecular weight; for atoms, the atomic weight.

Answer 2

Yes, except you use molecular mass of the molecule instead of the atomic mass of the element. The molecular mass of Cl2 is twice the atomic mass of Cl.