1. Electron Dot Diagrams (Lewis Dot)
Quick way to show bonding electrons (valence)
Use the atomic symbol to represent the nucleus and inner shell electrons.
Valence electrons ONLY are shown as dots around the symbol.
Arrange the dots around in a clockwise way, ending with electrons in pairs.

2. S Ca F Al Sulfur atom: 16 p+ 16 e- (6 valence e-) Calcium atom: 20 p+
Aluminum atom:
13 p+
13 e- (3 valence e-)
Fluorine atom:
9 p+
9 e- (7 valence e-) F Al

3. O Li Li Li O Oxygen atom: Lithium atom: 8 p+ 3 p+ 8 e- (6 valence e-)-2 + Li O
Lithium oxide 2

4. Potassium combines with chlorineK Cl - + K Cl
Potassium chloride

5. 2. Sodium combines with nitrogenNa N Na Na + -3 Na N
sodium nitride 3

6. 3. Lead (II) combines with sulfurPb S +2 -2 Pb S
lead (II) sulfide

7. Ca +2 S -2 Ca S
formula unit
Ionic Compound