[填空题]
Formamide has two resonance structures. One resonance structure A is shown.
1.Define the term resonance structures.
2.The hybridization of the nitrogen atom in resonance structure A is $_3$.
3.In the alternative structure B, the hybridization of the nitrogen atom is different.
Draw resonance structure B, including any non-zero formal charges and non-bonding electron pairs.
4.A 3D model of formamide is shown below:
Choose which resonance structure better represents the molecular geometry of formamide.