Question

There is no difference between the atomic and molecular masses of noble - gas elements.

• A. True
• B. False

Answer 1

The correct option is A True

Noble gases like $He,Ar,Kr$ etc. have completely filled outer electronic configuration and do not react with other elements to form compounds, nor do they form a molecule with the same atom of theirs. Therefore, they exist in monoatomic state and have same atomic and molecular mass.

Molecular orbital of Helium:-

(Refer to Image)

Bond order of $H{e}_2=\frac{Bondingelectrons-antibondingelectrons}{2}$

$\Rightarrow \frac{2-2}{2}=0$

Hence, there is no bond between two Helium atom and Helium exists as monoatomic and hence has same atomic and molecular mass. Similar is the case with other noble gases.