# Why is styrene and propene non-polar?

Well $C - C$ and $C - H$ are very non-polar bonds......
For a $C - H$ bond there is only marginal charge separation between the bound atoms; for a $C - C$ there should be no charge separation, as the bound atoms have no difference in electronegativity. For ethylene, ${H}_{2} C = C {H}_{2}$, even if there were bond polarity, the molecular dipole would be zero because of the symmetry. Maybe styrene, ${C}_{6} {H}_{5} C H = C {H}_{2}$ should be a little more polar, however, the difference should be marginal.