Question

The weight of 3.2×10*5 atoms of an element is 8.0×10*-18 gm. The atomic weight of the element should be about

Answer 1

1 mole of an element correspondence to 6.022*10^-23 atoms and also weighs same as it's atomic mass.

The weight of 3.2*10^-5 atoms is 8.8*10^-18, therefore weight of 6.022*10^-23 atoms is

(6.022*10^-23/3.2*10^-5) * 8.8*10^-18 = 16.5g
Thus the atomic mass of the element should be 16.5

Answer 2

Use Unitary Method

3.2×10^5 ------> 8.0 × 10^-18

as atomic weight is wt of 1mole of atom

6.02×10^23---> x

x=(6.02×10^23 × 8 ×10^18)÷3.2×10^5

x=15.05×10^10