Question

Does NO2- have a dipole?

Answer 1

Try drawing out the resonance structure. Which atom can make the most bonds? `"N"` or `"O"`? That atom should sensibly be in the center, right? So...

How many valence electrons does this have?

`"N"`: `5`
`"O"`: `2xx6 = 12`
From `-1` charge: `1`
Total: `18`

Did you get this?

If not, check your bonds. The major resonance structure has one double bond.

CHALLENGE: What are the formal charges here? Do you think a bent molecule has a dipole moment? Which direction does it point?

Hint: Try drawing the resonance hybrid structure, and consider dipole moment vector diagrams like these when determining how to draw your dipole moment vector.