SO3 - Sulfur Trioxide:
First draw the Lewis dot structure:
SO3 Lewis Structure
Electron geometry: trigonal planar. Hybridization: sp2

Then draw the 3D molecular structure using VSEPR rules:
Click and drag the molecle to rotate it.

The molecular geometry of SO3 is trigonal planar with symmetric charge distribution on the central atom.
Therefore SO3 is nonpolar.

Sulfur Trioxide on Wikipedia.
Back to Molecular Geometries & Polarity Tutorial: Molecular Geometry & Polarity Tutorial.
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