For noble gases, the radius is measured as van der Waals radius because these atoms are held together by weak van der Waals forces.
The Electron Configurations for Noble Gases
- Helium 1s2
- Neon [He] 2s2 2p6
- Argon [Ne] 3s2 3p6
- Krypton [Ar] 3d10 4s2 4p6
- Xenon [Kr] 4d10 5s2 5p6
- Radon [Xe] 4f14 5d10 6s2 6p6
- In the case of inert or noble gases, the shells are completely filled with electrons, and they are stable.
- As a result of this, due to the completely filled electronic configuration, the electronic repulsion in the noble gases are high.
- So the electrons tend to be away from each other to minimise this repulsion, leading to an increased atomic size of the noble gases.
- The atomic radius of the noble gases is determined by van der Waals radius, which is comparatively larger than ionic or covalent radii.