Question

Why do noble gases have comparatively large atomic sizes?

Answer 1

1. Noble gases have comparatively large atomic sizes because they do not form covalent bonds and hence, their atomic radii are measured in terms of van der Waals radii.
2. In contrast, for other elements, atomic radii are based on covalent bond distances, which are shorter.
3. Since van der Waals radii are larger than covalent radii, noble gases appear to have larger atomic sizes than the other elements in the same period.