There will be two other ressonance structures, both will follow the first pattern. First one: - The pi bond on the right will transform into a lone pair on the left carbon. - The lone pair from the negative carbon will transform into a pi bond. Second one: Based on the second structure (The one we just did), it will follow the same pattern. - The lone pair we just formed will move to form a pi bond in the left - The pi bond on the left will transform into a lone pair on the left carbon.
Work Step by Step
1. Draw the lone pairs. 2. Find which pattern does that structure fits. It is the second one for both structures, a lone pair next to a pi bond. 3. Draw the arrows: Follow the pattern for a lone pair next to a pi bond. 4. Do the changes based on the arrows. * Don't forget the formal charges!