Question

the atomic radius of noble gases is not smallest within a period .why?​

Answer 1

Answer:

i. Metallic/Covalent radius (left)

ii. Van der Waal radius (right)

It is believed that Noble gases don't form (or rather don't easily form bonds). This way only Van der Waals radius is measured.

The rationale here is based on the fact that noble gases have very low chemical reactivity and their atomic radii are non bonded.

Another explanation lies on electronic configuration of noble gases. They have completely filled outer orbitals with increased repulsion.

Answer 2

Answer:

1-"metallic.........