* Electronegativity: Oxygen has a high electronegativity, meaning it attracts electrons more strongly than other atoms.

* Bent Structure: Ozone has a bent molecular geometry, with a central oxygen atom bonded to two other oxygen atoms. This bent structure means the electron density is not distributed evenly.

* Unequal Sharing: The central oxygen atom is more electronegative than the terminal oxygen atoms. This causes the electron density to be pulled more towards the central oxygen, creating a partial negative charge on it and partial positive charges on the terminal oxygens.

Therefore, the O3 bonds are polar due to the unequal sharing of electrons and the bent structure of the molecule.