1. Chemical Bonding

2. Chemical Bond
The forces that hold groups of atoms together and make them function as a unit
Bonding involves only the valence electrons
There are 2 types of bonds:
Ionic: Transfer of electrons from a metal and to a nonmetal
Covalent: Sharing of electrons between 2 nonmetals
Note: When 2 metals bond an alloy is formed
Electrons are transferred or shared to give each atom a noble gas configuration (stable octet)
This is known as the octet rule

3. Lewis Diagrams
Valence electrons involved in bonding can be represented by Lewis dot diagrams
A chemical symbol represents the nucleus and the core electrons (not involved in bonding).
Dots around the symbol represent valence electrons.

4. Drawing Lewis DiagramsCl
Write the element symbol.
Draw dots, one for each valence electron
Dots should be spread over 4 sides
It does not matter what side the dots are placed, but do not start to pair dots until there is one on each side
The number of valence electrons is equal to the group number. With one exception.

5. Lewis diagrams for the first 20 elements