Slide 1

POLARITY How does electronegativity affect the polarity of a covalent bond? How does the shape of a molecule affect the polarity of a molecule?

Slide 2

Polarity Uneven sharing of electrons. Within a covalent bond Within an overall molecule A molecule can have polar bonds but be nonpolar. A molecule can have polar bonds and be polar. A molecule cannot have nonpolar bonds and be polar!

Slide 3

Bond Polarity Based on difference in electronegativity between atoms in a bond!

Slide 4

Which bonds are polar covalent? CC CH CO NF NaCl

Slide 5

Most electronegative elements: N, O, F

Slide 6

Polarity is not the whole story

Slide 7

Just because bonds are polardoesnt mean molecule is polar!

Slide 8

How about CH 4, CH 2 Cl 2, CH 3 Cl?

Slide 9

Practice: In your notebook, draw Lewis structures for the following. Identify individual bond polarities and overall polarity. Remember, lone pairs attract electronsso include lone pairs in your diagrams! Make the models if it makes you feel more comfortable! BCl 3, SiO 2, NF 3, N 2, CCl 4,