This document discusses Lewis structures and resonance structures. It defines resonance structures as multiple possible Lewis structures for a molecule that satisfy the octet rule. A double-headed arrow is used to connect resonance structures. As examples, it shows drawing the two resonance structures for ozone (O3) and the three resonance structures for carbon dioxide (CO2).

1. I can draw a Lewis structure, including resonance structures when necessary, for a given moleculeLearning Targets

2. So far, we’ve learned how to draw a Lewis structure to represent the covalent bonding that occurs in a molecule. Sometimes there is more than one possible Lewis structure for a molecule. All of the possible Lewis structures for a molecule are called “resonance” structures. Resonance Structures

3. Resonance structures are drawn using the same rules for Lewis structures. Resonance is possible when multiple bonds are necessary to create an octet on the central atom. If there is a choice when choosing a pair of electrons to move into a multiple bond, then there are resonance structures. Resonance structures are possible ONLY if there is a choice when creating multiple bonds. Resonance Structures

4. A double headed arrow ( ) is used in between the structures to indicate that they are in resonance with one another.

5. Ozone, O3Practice ProblemsDraw all possible resonance structures for the following molecules.

6. Ozone, O3Practice ProblemsDraw all possible resonance structures for the following molecules.. .. .. .OOO. .. .. .. .

7. Ozone, O3Practice ProblemsDraw all possible resonance structures for the following molecules.. .. .. .OOO. .. .. .. .Central atom octet not satisfied!

8. Ozone, O3Practice ProblemsDraw all possible resonance structures for the following molecules.. .. .. .OOO. .. .. .. .?One pair needs to be shared.

9. Ozone, O3Practice ProblemsDraw all possible resonance structures for the following molecules.. .. .. .OOO. .. .. .. .?If you have a choice, resonance structures exist!

10. Ozone, O3Practice ProblemsDraw all possible resonance structures for the following molecules.. .. .. .. .. .. .OOOOOO. .. .. .. .. .. .Ozone has two resonance structures. The completed structures have all octets satisfied.

11. Carbon DioxidePractice ProblemsDraw all possible resonance structures for the following molecules.

12. Carbon DioxidePractice ProblemsDraw all possible resonance structures for the following molecules.. .. .COO. .. .. .. .Central atom octet not satisfied!

13. Carbon DioxidePractice ProblemsDraw all possible resonance structures for the following molecules.. .. .COO. .. .. .. .?Two pairs need to be shared with carbon.

14. Carbon DioxidePractice ProblemsDraw all possible resonance structures for the following molecules.. .. .COO. .. .. .. .?You have a choice. Therefore, resonance structures exist.

15. Carbon DioxidePractice ProblemsDraw all possible resonance structures for the following molecules.. .. .. .. .COOCOOCOO. .. .. .. .. .. .. .. .Carbon dioxide has three resonance structures. The completed structures have all octets satisfied.