1. 8-2: Polarity

2. Remember electronegativity… An atom’s ability to attract electrons in a chemical bond. Polar bond: electrons are shared unequally between atoms Polar molecules, also called dipoles, have a positive end and a negative end

3. How do you determine whether a molecule is polar or not? H 2 No difference in polarity, so it is non- polar.

4. How do you determine whether a molecule is polar or not? CO 2 Draw it out Draw an arrow from the less electronegative atom to the more electronegative one The “pulls” cancel each other out, so the molecules is nonpolar.

5. How do you determine whether a molecule is polar or not? H 2 O Draw it The “pulls” do not cancel each other out, so the molecule is polar This is why water is a liquid at room temperature

6. How do you determine whether a molecule is polar or not? CH 2 O Draw it The “pulls” do not cancel each other out, so it is polar

7. Are the following polar or nonpolar? NH 3 Cl 2 CH 4 HCN C 2 H 4

8. Are the following polar or nonpolar? NH 3 polar Cl 2 nonpolar CH 4 nonpolar HCNpolar C 2 H 4 nonpolar