1. Lewis Dot Diagrams

2. Each row of the periodic table is called a period
All elements in a period have
the same number of
atomic orbitals (or shells)
Each column of the periodic table is called a group or family
All elements in a group
have the same number of
valence electrons

3. Na Lewis Dot Diagrams Method of representing atoms
Discovered by Gilbert N. Lewis
In a dot diagram, only the symbol for the element and the electrons in its outermost energy level (valence electrons) are shown
Eg: Sodium has 1 valence e- in it’s outermost shell, the diagram for sodium would look like this Na

4. Drawing Lewis Dot diagrams in 3 easy steps
Getting Started:
1. Find your element on the periodic table.
2. Determine the number of valence electrons.
-this will be determined by which group your element is in
(eg: Li is in group 1, so it has 1 valence electrons)
3. This is how many electrons you will draw.

5. Lone pair – electrons in atom’s valence shell (not used in bonding)
ex: Na
Bonding pair – electron pair involved in bonding
ex:  N

6. C Example 1 - Carbon Write the symbol for the element.
How many valence electrons does it have?
Start on the top and draw the electrons clockwise or counter-clockwise around the element .
Check your work— did you draw the correct number of electrons? C

7. Example 2 - Chlorine Cl

8. Your Turn Draw Lewis diagrams for the following:
Magnesium, Neon and Boron

9. Mg Ne B