16. How many equivalent resonance forms can be drawn for SO2 without expanding the octet on the sulfur atom?

16. How many equivalent resonance forms can be drawn for SO2 without expanding the octet on the sulfur atom? (A) 0 (B) 1 (C) 2 (D) 3 (E) 4 17. In which of these species does the first atom in the chemical formula violate the octet rule? 18. How many electron groups are around the N atom in the Lewis structure shown below?