1. Bohr Diagrams Find your element on the periodic table.
Determine the number of electrons – it is the same as the atomic number.
This is how many electrons you will draw.

2. Bohr Diagrams Find out which period (row) your element is in.
Elements in the 1st period have one energy level.
Elements in the 2nd period have two energy levels, and so on.

3. Bohr Diagrams Draw a nucleus with the Proton and Neutron count inside.
Carbon is in the 2nd period, so it has two energy levels, or shells.
Draw the shells around the nucleus.
P = 6
N = 6

4. C Bohr Diagrams Add the electrons. Carbon has 6 electrons.
The first shell can only hold 2 electrons.
P = 6
N = 6 C

5. Bohr Diagrams
Since you have 2 electrons already drawn, you need to add 4 more.
These go in the 2nd shell.
Add one at a time -starting on the right side and going counter clock-wise.
P = 6
N = 6 C

6. C Bohr Diagrams P = 6 N = 6 Check your work.
You should have 6 total electrons for Carbon.
Only two electrons can fit in the 1st shell.
The 2nd shell can hold up to 8 electrons.
The 3rd shell can hold 18, but the elements in the first few periods only use 8 electrons.
P = 6
N = 6 C

7. C Bohr Diagrams Try the following elements on your own: P = 6 N = 6 HAl Ne K
P = 6
N = 6 C

8. H Bohr Diagrams Try the following elements on your own: H – 1 electronAl Ne K H

9. Bohr Diagrams He Try the following elements on your own: H
He - 2 electrons O Al Ne K He

10. Bohr Diagrams O Try the following elements on your own: H He
O - 8 electrons Al Ne K O

11. Bohr Diagrams Al Try the following elements on your own: H He O
Al - 13 electrons Ne K Al

12. Bohr Diagrams Ne Try the following elements on your own: H He O Al
Ne - 10 electrons K Ne

13. Bohr Diagrams K Try the following elements on your own: H He O Al Ne
K - 19 electrons K

14. Valence Electrons
The number of electrons on an atom’s outermost energy level are referred to as valence electrons.
Valence electron counts determine how an element reacts with other elements. Al

15. Valence Electrons
An atom of Aluminum has three outermost energy level electrons, and therefore is said to have three valence electrons. Al

16. Lewis Structures Find your element on the periodic table.
Determine the number of valence electrons.
This is how many electrons you will draw.

17. Lewis Structures 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.

18. Groups - Review Group 8 = 8 electrons Group 1 = 1 electron
Except for He, it has 2 electrons
Group 2 = 2 electrons
Each column is called a “group”
3, 4, 5, 6, 7
Each element in a group has the same number of electrons in their outer orbital, also known as “shells”.
The electrons in the outer shell are called “valence electrons”

19. 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

20. C Lewis Structures Check your work.
Using your periodic table, check that Carbon is in the 4th group.
You should have 4 total electrons, or dots, drawn in for Carbon. C

21. C Lewis Structures On your worksheet, try these elements on your own:P Ca Ar Cl Al C

22. H Lewis Structures On your worksheet, try these elements on your own:P Ca Ar Cl Al H

23. P Lewis Structures On your worksheet, try these elements on your own:Ca Ar Cl Al P

24. Ca Lewis Structures On your worksheet, try these elements on your own:P Ca Ar Cl Al Ca

25. Ar Lewis Structures On your worksheet, try these elements on your own:P Ca Ar Cl Al Ar

26. Cl Lewis Structures On your worksheet, try these elements on your own:P Ca Ar Cl Al Cl

27. Al Lewis Structures On your worksheet, try these elements on your own:P Ca Ar Cl Al Al

28. You should know how to draw Lewis Structures for the first 20 elements.

29. 1 5
3 7 Xe