Question
Why do the noble gas elements have exceptionally high atomic radii?
Or
In a period, generally the size of the atom decreases with rise in atomic number, but at the end of each period, atomic size of the noble gas increases abruptly. Why is it so?
Solution
In the case of noble gases, we measure Vander Waal’s radii instead of covalent radii since these elements do not form covalent bonds. As by definition, Vander Waal’s radii are larger than covalent radii, the atomic size of an inert gas in a period is much higher than that of preceding halogen.
