- Neon is an inert gas while fluorine is a halogen. They both belong to period 2.
- The size of atoms of inert gases is greater than halogens of the same period.
- This is because the outermost shell of inert gases is complete.
- They have the maximum number of electrons in their outermost orbit thus the electronic repulsions are maximum.
- The effect of nuclear pull over the valence electrons is not seen.
- So, the atomic size of neon is greater than fluorine.