Question

Why are the elements of Group 18 known as noble gases?

Answer 1

Group 18 elements

The group 18 elements are $helium\left(He\right),neon\left(Ne\right),argon\left(Ar\right),krypton\left(Kr\right),xenon\left(Xe\right),\text{and}radon\left(Rn\right)$.

The elements present in Group 18 have their valence shell orbitals completely filled. Hence, they react with a few elements only under certain conditions. Therefore, they are known as noble gases.