PO₄³⁻ is a stable ion of phosphorous. Using Lewis structures, explain why NO₄³⁻ does not exist even though N and P are from the same group.

• A. NO₄³⁻ ion does not exist because N has a high electronegativity.
• B. NO₄³⁻ ion does not exist because N cannot have an expanded octet.
• C. NO₄³⁻ ion does not exist because N cannot be stable with a charge of −3.
• D. NO₄³⁻ ion does not exist because N atom is too small and cannot accommodate four O atoms around it.

Answer: (B)