Hybridization of nitrogen in rings.

[LogicX]

Homework Statement

I understand that the hybridization of, say, ammonia is sp³. I see that the nitrogen atom of pyridine is sp². I don't understand why the nitrogen of pyrrole is sp². I understand that it is aromatic and thus must be sp². But there are three bonds and one lone pair which would normally mean sp³.

How does this atom hybridize to sp²?

 

[chemisttree]

Is the lone pair isolated on the nitrogen or is it delocalized in the ring?

 

[LogicX]

It is delocalized... ah I think that explains it.