(આપેલ : $Mg$ નો પરમાણ્વીય દળ $24\, g\, mol ^{-1} ; N _{ A }=6.02 \times 10^{23}\, mol ^{-1}$ )
$W _{ Mg }=\frac{48 \times 2 \times 1000}{10^{6}}$
$=48 \times 2 \times 10^{-3} g$
$n _{ Mg }=\frac{ W _{ Mg }}{24}=\frac{48 \times 2 \times 10^{-3}}{24}$
$=4 \times 10^{-3}$
Number of $Mg$ atoms $=4 \times 10^{-3} \times 6.02 \times 10^{23}$
$=4 \times 6.02 \times 10^{20}$
$=24.08 \times 10^{20}$
$\therefore \quad x =24.08$