1. Chapter : Chemical Bonding
Cartoon courtesy of NearingZero.net

3. Chemical Bonds Lect1
Forces that hold groups of atoms together and make them function as a unit.
Ionic bonds – transfer of electrons Metal + Nonmetal Ex) NaCl Li2O
Covalent bonds – sharing of electrons. 2 nonmetals Ex) CH4 CO2
Metallic bonds- electrons are free to move throughout the material. Metals

4. Covalent Bonding
Molecule- is the smallest unit quanitity of matter which can exist by itself and retain all the properties of the original substance.
When a compound is formed by sharing electrons, the compound is called a
____Molecule__________________
Examples H2O & O2
Diatomic molecule- is a molecule containing 2 identical atoms. (H2 N2 O2 F2 Cl2 Br2 I2)
H NO F

5. Covalent Bonding
Diatomic molecule- is a molecule containing 2 identical atoms.
(H2 N2 O2 F2 Cl2 Br2 I2)
H NO F

6. Naming Covalent Compounds
Two words, with prefixes
Prefixes tell you how many.
1-mono, hexa
2-di, hepta (greek)
septa (latin)
3-tri, octa
4-tetra, nona
5-penta, deca

7. Naming Covalent Compounds
First element whole name with the appropriate prefix, except mono
Second element, -ide ending with appropriate prefix
Practice

8. Electornegativity
Lecture 3

9. Is it Covalent or ionic Nonpolar-Covalent bonds (H2)
Electrons are equally shared
Electronegativity difference of 0 to 0.5
Polar-Covalent bonds (HCl)
Electrons are unequally shared
Electronegativity difference between .5 and 2.1
3. Ionic Bonds

10. Using Electronegativity differences
CO = 1.0 polar covalent
C= look on table pg 198
O= thru 3.3= Ionic Bond

11. Electronegativity
Nonpolar Covalent Polar covalent Ionic  > 3.3

12. practice NaCl Na=0.9 Cl=3.2 3.2-0.9=2.3 NaCl is ionic
CO = Polar covalent
CH = Non polar covalent