What will be the mass of one ${ }^{12} \mathrm{C}$ atom in $\mathrm{g}$ ?

Solution:

1 mole of carbon atoms $=6.023 \times 10^{23}$ atoms of carbon

$=12 \mathrm{~g}$ of carbon

$\therefore$ Mass of one ${ }^{12} \mathrm{C}$ atom $=\frac{12 \mathrm{~g}}{6.022 \times 10^{23}}$

$=1.993 \times 10^{-23} \mathrm{~g}$