How many valid resonance structures can be drawn for ozone (O_3)?

• A. 2
• B. 4
• C. 3
• D. 1

Answer: (A)

Verified step by step guidance

1. Step 1: Understand what resonance structures are. Resonance structures are different Lewis structures for the same molecule that show the same arrangement of atoms but different placements of electrons, especially pi bonds and lone pairs.
2. Step 2: Draw the Lewis structure of ozone (O_3). Ozone has 18 valence electrons (6 from each oxygen atom). Arrange the three oxygen atoms in a row and connect them with single bonds initially.
3. Step 3: Distribute the remaining electrons to satisfy the octet rule for each oxygen atom. You will find that one oxygen will have a double bond with one neighbor and a single bond with the other, with formal charges appearing on the atoms.
4. Step 4: Identify the possible resonance structures by moving the double bond between the central oxygen and the terminal oxygens. This will create different valid Lewis structures with the same connectivity but different electron placements.
5. Step 5: Count the valid resonance structures. For ozone, there are two main resonance structures where the double bond shifts between the two terminal oxygens, each with appropriate formal charges to maintain overall charge neutrality.