How Do You Draw Correct Resonance Structures for H3CHCHC=NH?

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The discussion focuses on drawing correct resonance structures for the molecule H3CHCHC=NH, starting with an initial Lewis structure that was identified as an anion. The user calculated 24 valence electrons, distributing them to create a structure that was later deemed incorrect by Sapling. They then proposed a new resonance structure with a double bond between the second and third carbons and two lone pairs on nitrogen, which was accepted as correct. The concept of resonance is clarified, emphasizing that the actual structure is a hybrid of the significant resonance forms, with charge distribution primarily on the nitrogen atom. The proper representation of resonance forms involves using a double-headed arrow to indicate their contribution to the overall structure.
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Homework Statement


This is a problem with Sappling involved. I was given a Lewis Structure, told it was an anion (no charges were given just that it was one) and told to fix the structure and draw a resonance.

Homework Equations


No Equations.

The Attempt at a Solution


The problem starts out with the basic structure, there is a double bond between the carbon and the nitrogen, no charges and no lone pairs on the structure.

I counted up the number of valance electrons for this structure and got 23e-, since it's an anion, I added 1 extra electron (note they did not say the charge on the anion just that it was one). Now I have a total of 24 valence electrons in the molecule. The bonds take up 20 e- and that leaves 4 e- left over. I distributed a pair to the Carbon with 3 bonds (the first CH, or Carbon-2) and to the Nitrogen. This makes the Nitrogen neutral and gives the 2 carbon a -1 charge and the entire molecule has a -1 charge, an anion. But this is incorrect according to Sappling and I can't figure out another way to arrange the electrons so that the molecule makes sense.

As for the Resonance I pushed the electrons I had placed on the first model into different positions, putting a double bond between carbons 2 and 3 and a single bond between carbon 3 and the nitrogen. Also I gave the nitrogen 2 sets of lone pairs and a -1 charge. This resonance is correct according to sappling, but the initial model I amended is not.

I know it's not recommended to post a picture on here, but I'm drawing models and I don't see any other way to accurately describe what I have done, than to post a picture of my drawing so here it is:
http://imgur.com/6U0x4CI
 
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The 'original' drawing is missing a hydrogen atom, of course, which you added later.
"Resonance" is the character of having TWO significant resonance forms - forms in which the atoms are in the same place, but the charges are not. The actual structure has the charge distribution as a mixture of the two forms with their localized charges.
The major (most stable) resonance form is the one you show as "resonance" in your drawing; a less stable resonance form is the one labeled "my changes".
The proper way to show this (my opinion as practicing chemist) is to write the two forms with a double-headed arrow between them, showing that both contribute. In this case, most of the charge will be on the Nitrogen atom, much less on the Carbon atom
 
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