There will be only one other ressonance structure. It will follow the first pattern. The electrons from the pi bond will move to the oxygen so: - The pi bond will be removed - The oxygen will now have a negative formal charge. - The carbon that had that pi bond will get a positive formal charge. And, a lone pair from the nitrogen will form a pi bond between it and the positive carbon. - There will be a pi bond between these two. - The carbon will be neutral again. - The nitrogen will get a positive formal charge.
Work Step by Step
1. Draw the lone pairs. 2. Find which pattern does that structure fits. It is the first one, a lone pair (from the nitrogen) next to a pi bond. 3. Draw the arrows: Follow the pattern for a lone pair next to a pi bond. The electrons from the pi bond will move to the oxygen above them, so the carbon that lost the pi bond will get a positive charge. Then, the lone pairs from the other nitrogen will form a pi bond with this positive carbon. 4. Do the changes based on the arrows. * Don't forget the formal charges!