Question

1) what is the formula for number of molecules? 2) among 1mole of H²O, CO2,sodium atom, MgCl2 which one exhibit least number of particles ?
3) if you take 1molecule of H2O, CO2,MgCl2 which one is heavier?

Answer 1

2. sodium
1.No.of atoms ×atomic mass
3.Mgcl2

Answer 2

$1)no.of \: atoms \times atomic \: mss \times avogadro \: number \\ 2)sodium \\ 3)mgcl2$

see the above answer.