Question

Why does argon boil at a higher temperature than neon does?

Answer 1

Because `Ar` has a larger, more diffuse electron cloud than does `Ne`.

Explanation:

For `Ne`, `Z=10`, for `Ar`, `Z=18`. Thus argon has 8 extra electrons in a more diffuse electron cloud. The electron cloud of argon is thus more larger and more polarizable, and more able to express intermolecular dispersion forces. The result? The `"boiling point"` of `Ar=87.2K`; of `Ne=24.5K`.