Is water a polar molecule or an nonpolar molecule? How do you know?

Question

anonymous · Answer

Water is polar! We know because of the relatively high difference in electronegativity of Oxygen and Hydrogen. According to this http://www.webelements.com/electronegativity.html periodic table, which lists the electronegativity of each atom, Hydrogen has an electronegativity of ~4 while oxygen has an electronegativity of ~16. This high difference in electronegativity means that the oxygen "hogs" the shared electrons. This creates a bipole in the water molecule. Since the electrons spend more time orbiting the oxygen atoms, the side of the molecule that contains hydrogen has a positive net charge.