CHY 122 - Chapter 9: Molecular Geometry and Bonding Theories

molecular shapes

shape is determined by bond angles and influences reactivity

VSEPR theory

the best arrangement of electron pairs around a central atom minimizes repulsions

electron domain

each lone pair, single bond, or multiple bond around the central atom

electron domain geometry (EDG)

the arrangement of electron domains about the central atom

regular

bond lies flat on the paper

dashes

bond points backwards

wedges

bond points forward

linear

2 domains, 180 degrees

trigonal planar

3 domains, 120 degrees

tetrahedral

4 domains, 109.5 degrees

trigonal bipyramidal

5 domains, 90 degrees and 120 degrees

octahedral

6 domains, 90 degrees

molecular geometry

only the bonding electron pairs (atoms) around the central atom

axial

form a line through the center of the molecule

equatorial

form a triangle around the center of the atom