Sulfur trioxide has a trigonal planar electron geometry, according to David Roth of Tutoring & Homework Help. SO3 has a central sulfur atom and three surrounding oxygens, with a total of 24 valence electrons. Two oxygens form single bonds with sulfur, while one forms a double bond.
The central sulfur atom of SO3 has an oxidation state of +6 and a formal charge of +2. In an SO3 compound, three oxygen atoms are positioned at the corners of a triangle, all in one three-dimensional plane. The bond angles between all oxygens is 120 degrees. SO3 is centrosemetric and has no electric dipole.