The number of atoms that are in 0.32 g of copper are
3.01 x10^21 atoms
calculation
Step 1: find the number of moles of Copper
moles = mass/molar mass
= 0.32 g /63.5 g/mol=0.005 moles
Step 2: use the Avogadro's constant to determine the number of atom
in 0.005 moles of Cu
that is according to Avogadro's law 1 mole =6.02 x10^23 atoms
0.005 moles=? atoms
by cross multiplication
= (0.005 moles x 6.02 x10^23 atoms) / 1 mole= 3.01 x10 ^21 atoms