How many moles of sodium will have same number of atoms as 5 g of copper?

Answer 1

mols Cu in 5 g Cu = 5.00/63.55 = ??
# atoms in that many mols Cu will be the same for ANY monatomic element.
If you want the grams of Na in this amount, then mols = g/atomic mass OR
g = mols x atomic mass = ??mols x 23 (Look up the atomic mass of Na to make sure that is right).

Answer 2

question is confusing. Is the answer 2.1789 mol of Na?

Answer 3

No. Re-read my response. It clearly says
mols Cu = 5.00/63.55 = ?? and that will be the mols Na or any other monatomic element of your choosing. Punch in 5.00 and divide by 63.55 and I don't get 2.17