Question

Which has more no.of atoms 50g of aluminium or 50g of iron ? Illustrate ur answer with the help of calculations

Answer 1

Atomic mass of Al = 27 u
      So 27 gms of Aluminum contains N = 6.022*10²³ atoms
           50 gms of Al contains :  50 N/27  atoms

Atomic mass of Fe =  56 u
      So 56 gms of Fe contains  N  atoms
           50 gms of Fe contains   50N/56  atoms

Clearly  Aluminum has more number of atoms.  This is because Aluminum has a smaller atomic mass and is lighter.
I hope it will help you