Shapes of Molecules VSEPR Theory

VSEPR Theory

Valence shell electron pair repulsion theory

Assumptions of VSEPR Theory

1. Valence shell electrons bond atoms. 2. Electron pairs repel to maximize distance. 3. Lone pairs are more repulsive than shared pairs.

Lewis Dot Diagram

Best for determining molecule shape by showing surrounding atoms and lone pairs.

Linear

Molecular shape with 180° bond angle, like diatomic molecules.

Angular/Bent

Molecular shape with 104.5° bond angle, 2 surrounding atoms, and 1 lone pair.

Trigonal Planar

Molecular shape with 120° bond angle, 3 surrounding atoms, and no lone pairs.

Trigonal Pyramidal

Molecular shape with 107° bond angle, 3 surrounding atoms, and 1 lone pair.

T-Shaped

Molecular shape with 180° and 90° bond angles, 3 surrounding atoms, and 2 lone pairs.

Tetrahedral

Molecular shape with 109.5° bond angle, 4 surrounding atoms, and no lone pairs.

Seesaw

Molecular shape with 180° and 90° bond angles, 4 surrounding atoms, and 1 lone pair.

Square Planar

Molecular shape with 90° bond angles, 4 surrounding atoms, and 2 lone pairs.

Trigonal Bipyramidal

Molecular shape with 120° and 90° bond angles, 5 surrounding atoms, and no lone pairs.

Square-Based Pyramid

Molecular shape with 90° bond angle, 5 surrounding atoms, and 1 lone pair.

Octahedral

Molecular shape with 90° bond angles, 6 surrounding atoms, and no lone pairs.