MOLECULAR GEOMETRY TYPES

MOLECULAR GEOMETRY ||| Types II

ORGANIC MOLEC. GEOMETRY  Elmhurst College
Lewis Diagrams Trigonal Planar  Trigonal Pyrimid  Chemistry Department
Linear Tetrahedral Bent  Virtual ChemBook

 
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 Electron Pair and Molecular Geometry Types
Molecular geometry is associated with the specific orientation of bonding in atoms. A careful analysis of electron distributions through the writing of Lewis diagrams will usually result in correct electron pair and molecular geometry determinations.

Valence Shell Electron Pair Repulsion (VSEPR) theory:

Principle: Electron pairs around a central atom arrange themselves so that they can be as far apart as possible from each other.

This method gives the electron pair geometry.

Geometry Types:
The most common geometry types are defined by the number of electron pairs around an atom. Electron pairs are defined as electrons in bonds (single, double, or triple), lone pairs, and occasionally a single unpaired electron. The various geometries are shown in the graphic on the upper left.

   
 Electron Pairs

 2

 3

 4

 Electron Pair Geometry

 Linear

 Trigonal Planar

 Tetrahedral

 Molecular Geometry

 0 lone pairs
Linear

 0 lone pairs
Trigonal Planar

 0 lone pairs
Tetrahedral

-

  1 lone pair
Bent

 1 lone pair
Trigonal Pyramid

 -

 -

 2 lone pairs
Bent