Polar & Nonpolar

[804991762_4A]

In determining whether a molecule is polar or nonpolar, how do you know the charges of each atoms?

[Sunjum Singh 1I]

It's based on the atoms electronegativity. So in the case of H20, we know oxygen is more electronegative(wanting more electrons) than hydrogen, so electrons are going to be pulled more towards oxygen. This causes hydrogen to become slightly positive and oxygen to be more negative. This is why H20 is a polar bond.

[John Miller-1I]

To elaborate on the above on how to determine which element will be more positive/negative, you can look at a periodic table with electronegativity listed. The element that is more electronegative will attract electrons the most and therefore be partially negative in a polar bond

[Neha Divi 1K]

In addition, we learned in class on Friday that a polar molecule must have polar bonds with dipoles that do not cancel and that a non polar molecule must have zero electric dipole moment which is possible if it contains non polar bonds or polar bonds with dipoles that cancel.