The SNO⁻ ion and the NSO⁻ ion are two simple ions from a large family of compounds called the NSO compounds. These compounds are mainly found in geological formations within asphaltenes and other mixtures. The SNO⁻ ion is more stable than the NSO⁻ ion. Draw Lewis structures for both ions including any resonance forms. Use formal charges to determine why SNO⁻ ion is more stable than the NSO⁻ ion.

• A. SNO⁻ ion is more stable because all of its resonance forms have a minimum of formal charges.
• B. SNO⁻ ion is more stable because all of its resonance forms have zero formal charges.
• C. NSO⁻ ion is more stable because the sulfur atom in one of its resonance forms has an expanded octet.
• D. NSO⁻ ion is more stable because its nitrogen atom in one of its resonance forms has a formal charge of +2.

Answer: (A)