Why do noble gas have comparatively large atomic sizes?

Explanation

The atomic sizes of noble gases are by far the largest in their respective periods. Noble gases do :
not form molecules and hence have only van der Waals..radii: vàn der Wäls" radii by definition. are Iarger than covalent radii which the.molecules usually have. As we move down. these atomic sizes further increase primarily due to the increase in the
-number of shells.