1. E LECTRON (L EWIS ) D OT D IAGRAMS

2. V ALENCE E LECTRONS valence electrons – electrons in the highest unfilled energy level -These are the electrons that make chemical bonds. What is the highest energy level that has electrons? How many valence electrons does lithium have? 2 1 Lithium (Li) 1s 2 2s 1

3. 2 W AYS TO D ETERMINE V ALENCE E LECTRONS 1) Count the valence electrons from the Bohr model. 3) Use the PToE. 2) Count the valence electrons from the electron configuration.

4. D RAWING L EWIS D OT D IAGRAMS How many electrons are in sodium’s outer energy level? What does the electron dot diagram look like? 1) Count the valence electrons from the Bohr model. 1 Na 

5. D RAWING L EWIS D OT D IAGRAMS How many electrons are in carbon’s highest energy level? What does the electron dot diagram look like? Carbon’s electron configuration is: 1s 2 2s 2 2p 2 What is the highest ENERGY LEVEL in carbon? 2) Count the valence electrons from the electron configuration. 2 + 2= 4 CC 2

6. D RAWING L EWIS D OT D IAGRAMS A) Determine what column on the PToE the element is in. What column is carbon in? STEPEXAMPLE 3) Use the PToE. Column 14

7. D RAWING L EWIS D OT D IAGRAMS B) Use the following table to determine how many valence electrons that column has. Carbon – Column14 How many valence electrons do elements in column 14 have? STEPEXAMPLE 3) Use the PToE. Column12131415161718 Valence Electrons 12345678 4

8. D RAWING L EWIS D OT D IAGRAMS C)Draw the Electron Dot Diagram. Start on one side and work your way around. 1-4 Valence Electrons: No more than 1 dot per side. 5-8 Valence Electrons: Some sides will have 2 dots Carbon – 4 Valence electrons C STEPEXAMPLE 3) Use the PToE.

9. D RAWING E LECTRON D OT D IAGRAMS Draw the Dot Diagram for magnesium (Mg). Mg Electron Configuration: 1s 2 2s 2 2p 6 3s 2 Highest Energy Level: 3 Electrons in Highest Energy Level: 2 Column Number: 2

10. D RAWING E LECTRON D OT D IAGRAMS Draw the Dot Diagram for arsenic (As). As Electron Configuration: 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 3 Highest Energy Level: 4 Electrons in Highest Energy Level: 5 Column Number: 15

11. D RAWING E LECTRON D OT D IAGRAMS Draw the Dot Diagram for helium(He). He: Electron Configuration: 1s 2 Highest Energy Level: 1 Electrons in Highest Energy Level: 2 Column Number: 18 Note: Helium is weird! It doesn’t follow the pattern.