VSEPR Theory Chem Memorization

2 Electron Domains (0 Lone Pairs)

Electron Domain Geometry: Linear
Shape: Linear
Bond Angle: 180°
Example: CO₂

3 Electron Domains (0 Lone Pairs)

Electron Domain Geometry: Trigonal Planar
Shape: Trigonal Planar
Bond Angle: 120°
Example: NO₃⁻

3 Electron Domains (1 Lone Pair)

Electron Domain Geometry: Trigonal Planar
Shape: Bent
Bond Angle: <120°
Example: O₃

4 Electron Domains (0 Lone Pairs)

Electron Domain Geometry: Tetrahedral
Shape: Tetrahedral
Bond Angle: 109.5°
Example: CH₄

4 Electron Domains (1 Lone Pair)

Electron Domain Geometry: Tetrahedral
Shape: Trigonal Pyramidal
Bond Angle: <109.5°
Example: NH₃

4 Electron Domains (2 Lone Pairs)

Electron Domain Geometry: Tetrahedral
Shape: Bent
Bond Angle: <<109.5°
Example: H₂O

C-H Bond Exception

Carbon-Hydrogen bonds have a very small electronegativity difference, so they are treated as nonpolar covalent bonds.

Nonpolar Molecule Rule

A molecule is nonpolar if it is symmetrical (linear or tetrahedral), has no central lone pairs, and its bond dipoles completely cancel each other out in a tug-of-war

Polar Molecule Rule

A molecule is polar if it is asymmetrical (trigonal pyramid) or has central lone pairs that disrupt symmetry, preventing bond dipoles from canceling out