The formula for copper(II) phosphate is: Cu3(PO4)2
Thus, for every mol of Cu3(PO4)2, there is 2 mol of phosphate atoms.
2 x 4.40 = 8.80 mol.
Using Avagadro's number, we can now calculate the number of phosphate atoms:
N = n x N(A)
(N=number of atoms, n=amount in mole, N(A)=6.02x10^23 - Avagadro's number)
Therefore:
N = 8.80 x (6.02x10^23)
= 5.29 x 10^24
