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. 3 W AYS TO D ETERMINE V ALENCE E LECTRONS 1) Given a Bohr model, count the electrons in the outer energy level. 3) Use the Periodic Table. 2) Given an Electron Configuration, count the electrons in the highest energy level.

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) Given a Bohr model, count the electrons in the outer energy level. 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) Given an Electron Configuration, count the electrons in the highest energy level. 2 + 2= 4 CC 2

6. D RAWING L EWIS D OT D IAGRAMS A) What column on the PToE is the element in? What column is carbon in? STEPEXAMPLE 3) Use the Periodic Table. 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 (Lewis) Dot Diagram. Start on one side and work your way around. STEPEXAMPLE 3) Use the PToE.

9. D RAWING L EWIS D OT D IAGRAMS 1-4 Valence Electrons: 5-8 Valence Electrons No more than 1 dot per side.Some sides will have 2 dots. Carbon – 4 Valence electrons C 3) Use the PToE. Sulfur – 6 Valence electrons S

10. 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 Valence Electrons: 2

11. 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: 2 + 3 = 5 Column Number: 15 Valence Electrons: 5

12. 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.