Question

Which has more atoms,50g of aluminium or 50g of iron? Illustrate your answer with the help of calculations..(Atomic masses:Al=27u; Fe=56u).

Answer 1

Aluminium has more atoms because Its atomic mass is lesser therefore 50g of Aluminium can accommodate more atoms.
For Aluminium =50/27= 1.85
For Iron =50/56= 0.89
There Aluminium has more.

Answer 2

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.