◦ Atoms of some elements pull more strongly on shared electrons than do atoms of other elements. As a result, the electrons are pulled more toward one atom, causing the bonded atoms to have slight electrical charge.
Polar bonds: A covalent bond in which electrons are shared unevenly
Non-polar bond: covalent bond in which the electrons are shared equally. See figure 17, page 170
◦ A molecule with non-polar bonds will itself be non-polar. But, a molecule may contain polar bonds and still be non-polar overall.
◦ A carbon dioxide molecule is a non- polar molecule because it’s a straight line shape. In contrast a water molecule is polar because of its bend shape. The bent shape allows the O end to have a slight negative charge and the H₂ end to have a slight positive charge
◦ Attraction between molecules ◦ Polar molecules require more energy to break the bond than non-polar molecule