Consider structural formulas
A,B and
C (a) Are
A,B and
C constitutional isomers, or are they resonance forms?
(b) Which structures have a negatively charged carbon?
(c) Which structures have a positively charged carbon?
(d) Which structures have a positively charged nitrogen?
(e) Which structures have a negatively charged nitrogen?
(f) What is the net charge on each structure?