Question

How many atoms are there in 0.32g of copper

Answer 1

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