Carbon dioxide (CO₂) is made out of two atoms of oxygen (O) and one atom of carbon (C). The two oxygen atoms share a double covalent bond with carbon: O=C=O. The bond angle between carbon and oxygen is 180°. As can be seen from the image, CO₂ has a linear and symmetrical shape ^[1-4].

Oxygen is more electronegative than carbon. The shared electron pairs will be pulled toward it. As a result, the two oxygen will acquire partial negative charges, and carbon will acquire a partial positive charge. Each C=O bond will have a dipole moment, and the two dipole moments are equal and opposite in direction. They will cancel, leaving a net zero dipole moment. Therefore, CO₂ is overall a polar molecule.