Why are homonuclear diatomic molecules non-polar?

1 Answer
Jul 7, 2016

Because the elements that comprise a homonclear halogen molecule, #X_2#, clearly have equal electronegativies.

Explanation:

A homonculear diatomic molecule, #X_2#, is composed of 2 halogen atoms, which have the same electronegativity. Given this, there can be no charge separation, and no possibility of polarity in the #X-X# bond.

Molecules such #I-Cl# or #F-Br# can certainly exist. Such molecules would exhibit a dipole as there would be unequal sharing of electron density.