1. Old students…help the new ones and explain how warm-ups work!
Read the comic on your table. Explain how metals, nonmetals, and metalloids differ in they way that they desire electrons.
Warm-Up 1/30/14

2. Let’s go over the homework from yesterday!

3. VSEPR and Molecular Polarity
Thursday 1/30/14

4. Review: Covalent Bonding
When nonmetals bond, they share electrons. This is called “covalent bonding.”
Nonmetals share electrons so the atoms can gain Noble Gas Configuration, or a full octet (eight valence electrons— typically)
Review: Covalent Bonding

6. Polarity refers to how exactly the electrons are being shared in a bond.
Nonpolar: equal sharing. Ex) H2
Polar: Unequal sharing. Ex) OH
What is Polarity?

7. Who gets the bigger share of electrons?
Electronegativity: a measure of how well an atom attracts electrons to itself.
All atoms have an assigned electronegativity value, larger #s meaning they are better at pulling electrons.
An atom with a higher electronegativity will get a bigger share of the electrons, and appear slightly negative.
Who gets the bigger share of electrons?

8. Chlorine has a higher electronegativity, and becomes slightly negative.
This is a POLAR bond because there is significant UNEQUAL sharing.
Example

9. By definition, a bond is polar when the difference in electronegativity is between 0.4 and 1.7
More specific than last semester!
Nonpolar is anything less than 0.4, Ionic is anything larger than 1.7
When is it Unequal?

10. When is a whole MOLECULE polar?
By combining VSEPR and polarity ideas, we can determine if a whole molecule is polar.
It is like tug-of-war, with attached atoms fighting over the central atom!
When is a whole MOLECULE polar?

11. To be a polar molecule it must have…
Polar bonds or lone pairs
A molecular shape where the polar bonds or lone pairs do not cancel out

13. Complete the table at the end of your notes. Due tomorrow 
Your Job