VSEPR theory

• VSEPR refers to Valence Shell Electron Pair Repulsion​.

• ​This theory states that "pairs of electrons (in bonds and in lone pairs) repel each other"

• ​Electrons try to be as far as possible from each others because that makes them more stable.

• ​​This repulsion between valence electrons affects the 3D shape of a molecule.

• ​Hence, this theory allows us to predict a molecule's 3D shape.

​Linear

​Bent

​Bent

​Trigonal planner

​Tetrahedral

​Trigonal pyramidal

​A molecule is given an AXE #, where:

• A is the central atom.

• X is a terminal atom.

• E is a nonbonding valence electron (a lone pair of electrons)

• ​A is the central atom = 1

• X is a terminal atom = 2​

• ​E is a lone pair = 2

• ​

• ​So AXE # of water = AX₂E₂