NH3 - Ammonia:

First draw the Lewis dot structure:
NH3 Lewis Structure
Electron geometry: tetrahedral. Hybridization: sp3

Then draw the 3D molecular structure using VSEPR rules:

The molecular geometry of NH3 is trigonal pyramidal with asymmetric charge distribution on the central atom.
Therefore this molecule is polar.

Ammonia on Wikipedia.

Back to Molecular Geometries & Polarity Tutorial: Molecular Geometry & Polarity Tutorial.

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