1. Molecules EQ: How are the electrons arranged in a covalent bond?
Ch. 9 Covalent Bonds

2. Electron Sharing Produces Molecules
Covalent bonds are formed when atoms produce stable octets by sharing valence electrons to form Molecules.

3. Bonding Video

4. X O Lewis Structures 2s 2p Electron Dot Diagrams
show valence e- as dots
distribute dots like arrows in an orbital diagram
4 sides = 1 s-orbital, 3 p-orbitals
EX: oxygen X 2s 2p O

5. Ne Lewis Structures Octet Rule
Most atoms form bonds in order to obtain 8 valence e-
Full energy level stability ~ Noble Gases Ne

6. Single, Double or Triple Covalent Bonds
Single Bonds
Carbon & Hydrogen
Double Bonds
Sulfur
Oxygen
Triple Bonds
Nitrogen

7. Lewis Structures
Nonpolar Covalent - no charges, electrons are shared equally
Polar Covalent - partial charges, electrons are shared unequally + -
C. Johannesson

8. Polarity
POLARITY: More electronegative atoms attract electrons more strongly, and thus electrons are not always shared equally. The slight separation of charge is Polarity. Water is a very polar covalent molecule.

9. Molecular Nomenclature
Prefix System (binary compounds)
1. Less e-neg atom comes first.
2. Add prefixes to indicate # of atoms. Omit mono- prefix on first element.
3. Change the ending of the second element to -ide.

10. Molecular Nomenclature
PREFIX mono- di- tri- tetra- penta- hexa- hepta- octa- nona- deca-
NUMBER

11. Molecular Nomenclature
CCl4
N2O
SF6
carbon tetrachloride
dinitrogen monoxide
sulfur hexafluoride

12. Molecular Nomenclature
arsenic trichloride
dinitrogen pentoxide
tetraphosphorus decoxide
AsCl3
N2O5
P4O10

13. Molecular Nomenclature
The Seven Diatomic Elements
Br2 I2 N2 Cl2 H2 O2 F2 H N O F Cl Br I
C. Johannesson

14. Draw the Lewis dot structures for the following covalently bonded atoms
H2 , CH4 , NH3 , H2 CCH2 , N2 , Cl2