Question

calculate the number of atoms present in 6.4 g of sulphur.

Answer 1

number of mole = weight/ atomic weight
                       = 6.4/32
                       = 0.2 mole
1 mole = 6.023*10^23 atom
hence
0.2 mole - 0.2*6.023*10^23 atom
0.2 mole = 1.2046*19^23 atom

Answer 2

number of moles=weight/atomic weight
      
                        =6.4/32
                         =0.2