Why are the vinylic bonds in alkenes slightly polar? when searching in the internet about why are alkenes more polar than alkanes (but still they are non-polar), they are always saying that the double bond is more polarizable , i understood the whole story about how the sp2 attract electrons from the sp3 and forming london forces, but they always said that vinylic bonds are slightly polar but i never understood why.
Maybe because of resonance:

$H_{2}C=CH_{2}$    $\leftrightarrow$    $H_{2}C^{-}-C^{+}H_{2}$