If mass one atom is $3.32\times {10}^{-23}\mathrm{g}$, then calculate number of nucleons (neutrons and protons) present in 2 atoms of the element :

Number of nucleons=mass number.

Molar mass of element $=3.32\times {10}^{-23}\times 6.02\times {10}^{23}$

                                          $\cong 20=\text{ Mass number }$

So, number of nucleons in 2 atoms =40