CHM 1045 California State University Long Beach Lewis Structure Worksheet

Drawing a Lewis Structure:

You will use the following steps in this worksheet in order to draw a Lewis Structure. Apply the rules in order.

Lewis structure Recipe

1. Count available electrons (ae) – based on the column on the Periodic Table

2. Draw structure showing single bonds between atoms. Least electronegative atom as the central atom

3. Add electrons to make every atom follow the octet rule or duet rule for hydrogen.

4. count the number of necessary electrons (ne) for your trial structure. Compare ne to ae.

a. if ne = ae then go to step 7.

b. if ne < ae, go to step 5.

c. if ne > ae go to step 6.

5. Add electrons to the central atom if it is in period 3 or higher.
Then, go to 7.

6. erase two pairs and make one double bond, unless the central atom is column IIA or IIIA (they may have less than an octet, thus go to 7.) Go to 4.

halogens and hydrogen will not form double bonds.

C, O, N, P, S, and Se easily form multiple bonds

7. END