Which of the following characteristics is preferred for a better resonance structure?

• A. There are as many formal charges as possible
• B. All atoms have complete $\mathrm{octets}$ where possible
• C. There are unpaired electrons on most atoms
• D. Negative charges are placed on less electronegative atoms

Answer: (B)

Verified step by step guidance

1. Understand that resonance structures are different Lewis structures for the same molecule that differ only in the placement of electrons, not atoms.
2. Recall that the most stable and preferred resonance structures generally have atoms with complete octets, meaning each atom (especially second-row elements like C, N, O, F) has eight electrons in its valence shell where possible.
3. Recognize that minimizing formal charges is important; resonance structures with fewer formal charges are usually more stable than those with many formal charges.
4. Note that placing negative charges on more electronegative atoms (like oxygen or nitrogen) is preferred because these atoms better stabilize negative charge.
5. Avoid resonance structures with unpaired electrons on most atoms unless the molecule is a radical, as paired electrons contribute to stability.