1. Chemical Bonding

2. Chemical Bonds
Chemical Bond: a mutual attraction between the nuclei and valence electrons of different atoms that bonds atoms together.
Valence electrons: electrons available to be gained lost or shared to form chemical bonds.
Located in the outer most s and p orbitals

3. Valance Electrons
Calcium?
Bromine?
Aluminum?

4. Types of Bonds
Covalent bond: results from the sharing of electron pairs between two atoms
Ionic bond: results from the attraction between positively and negatively charged atoms
Metallic bond: results from an attraction between metal atoms and a surrounding sea of electrons

5. Ionic Bonds
Atoms can gain or lose electrons to have a complete outer shell of electrons (valence electrons).
Metals always lose electron and become positive.
Aluminum has 3 valence e-. It will lose all its e- to have a +3 charge
Nonmetals always gain electrons and become negative.
Oxygen has 6 valence electrons. It will gain 2 e- to have 8 e- to have a -2 charge.

6. Charges N?
Li? C?
Cl?

7. Polar Bonds Polar: an uneven distribution of charge
Polar-Covalent Bond: a covalent bond in which the bonded electrons are shared unequally
Nonpolar-Covalent Bond: a covalent bond with a balanced sharing of electrons

8. What type of bond??
You can determine if a bond is nonpolar-covalent, polar-covalent, or ionic by looking at the difference in electronegativity.
What is electronegativity?
What does difference mean?
Turn to pg 151 in your textbook.

9. Electronegativity Values

10. What type of bond?? A difference of < .5
A difference of .5 ≤ x < 2.0
A difference of ≥ 2.0

11. What type of bond?? Sulfur and Hydrogen? Bromine and Potassium?
Cesium and Phosphorus?
Sodium and Chlorine?