Among the following, minimum number of atoms are present in

GAW of Cu, Cl, H, He are 63.6g, 35.5g, 1g and 4g respectively.

$\therefore$  1 gram each of them contain $\frac{{\mathrm{N}}_{\mathrm{A}}}{63.6},\frac{{\mathrm{N}}_{\mathrm{A}}}{35.5},\frac{{\mathrm{N}}_{\mathrm{A}}}{1},\frac{{\mathrm{N}}_{\mathrm{A}}}{4}$ atoms