Question

Give appropriate reason for the following observation:

Only higher members of group 18 of the periodic table are expected to form compounds.

Answer 1

1. Lower members like helium, neon, and argon have very stable, completely filled valence shells and very high ionization energies, making them chemically inert.
2. Higher noble gases such as xenon and radon have larger atomic sizes and lower ionization energies, allowing their outer electrons to be more easily involved in bonding.
3. They also have available vacant d-orbitals, which help in forming compounds through expanded valence shells. Thus, only heavier noble gases form compounds under suitable conditions.