1. Valence Electrons and Lewis Dot Diagrams
Ms. Khericha and Ms. Rowland

2. Electron Cloud
Electron Cloud

3. Energy Levels

4. Valence electrons
Valence electrons are the electrons farthest away from the nucleus.
Every group of elements will have a different number of valence electrons

5. Why are valence electrons important?
Valence electrons are key to whether or not an atom bonds with another atom
The number of valence electrons is the “face” an atom shows to other atoms
One way to show valence electrons is with electron dot diagrams or Lewis dot diagrams

6. Lewis dot diagrams
Lewis dot diagrams include the symbol for the element surrounded by dots. Each dot stands for one valence electron
Hydrogen
Hydrogen H
Nucleus

7. How to find the # of valence electrons
Find out which group (column) your element is in.
This will tell you the number of valence electrons your element has.
You will only draw the valence electrons.

8. Groups Elements in group 1 will have only 1 valence electron
Group 1 = 1 electron

9. Groups Elements in group 2 will have only 2 valence electron
Group 2 = 2 electrons

10. Groups Elements in group 3 will have only 3 valence electron
Group 3 = 3 electrons

11. Groups Elements in group 4 will have only 4 valence electron
Group 4 = 4 electrons

12. Groups Elements in group 5 will have only 5 valence electron
Group 5 = 5 electrons

13. Groups Elements in group 6 will have only 6 valence electron
Group 6= 6 electrons

14. Groups Elements in group 7 will have only 7 valence electron
Group 7 = 7 electrons

15. Groups Elements in group 8 will have only 8 valence electron
Group 8 = 8 electrons
Except for He, it has 2 electrons

16. Groups - Review Group 8 = 8 electrons Group 1 = 1 electron
Except for He, it has 2 electrons
Group 2 = 2 electrons
3, 4, 5, 6, 7

17. How to: Lewis Structures
Find your element on the periodic table.
Determine the number of valence electrons.
This is how many electrons you will draw.
Draw them starting at the right, and in a counterclockwise manner.

18. Lewis Structures
Write the element symbol. C

19. C Lewis Structures Write the element symbol.
Carbon is in the 4th group, so it has 4 valence electrons. C

20. C Lewis Structures Write the element symbol.
Carbon is in the 4th group, so it has 4 valence electrons.
Starting at the right, draw 4 electrons, or dots, counter-clockwise around the element symbol. C

21. Practice!

22. Lewis Structures H

23. Lewis Structures H

24. Lewis Structures P

25. Lewis Structures P

26. Lewis Structures Ca

27. Lewis Structures Ca

28. Lewis Structures Ar

29. Lewis Structures Ar

30. Lewis Structures Cl

31. Lewis Structures Cl

32. Lewis Structures Al

33. Lewis Structures Al

34. Assignment
You will have the rest of the hour and the weekend to complete the Lewis structures assignment