How can I predict whether a molecule is polar or not?

I have question concerning the difference between a molecule being polar or nonpolar...for example H2O is polar and CCl4 is nonpolar. How in the world am I suppose to distinguish that? I am looking at a chart that is showing...ion-dipole, dipole-dipole, dipole-induced dipole, induced dipole-induced dipole...Help!!!! It was suppose to be the summary and I have no clue what they are talking about. Maria Chang 8/26/99: Author: Fred Senese senese@antoine.frostburg.edu

General Chemistry Online! How can I predict whether a molecule is polar or not?