Molecular Geometry Practice
VSEPR theory predicts shape by counting electron domains on the central atom: domains spread out to minimize repulsion, and lone pairs shape the molecule without appearing in the geometry's name.
Identify the molecular geometry of each molecule below, using the Lewis structure and 3D model as guides.
What is the molecular geometry?
Common Questions
What is VSEPR theory?
VSEPR (Valence Shell Electron Pair Repulsion) theory predicts molecular geometry by assuming electron groups around a central atom repel each other and arrange themselves as far apart as possible.
How do you determine molecular geometry using VSEPR?
Count the electron groups (bonding pairs and lone pairs) around the central atom. The electron geometry is based on the total count. The molecular geometry describes only the positions of the atoms, ignoring lone pairs.
What is the difference between electron geometry and molecular geometry?
Electron geometry considers all electron groups (bonding + lone pairs). Molecular geometry only describes where the atoms are. For example, 4 electron groups with 1 lone pair gives tetrahedral electron geometry but trigonal pyramidal molecular geometry.
What common molecular geometries should I know?
Key shapes: linear (2 groups, 180°), trigonal planar (3 groups, 120°), tetrahedral (4 groups, 109.5°), trigonal bipyramidal (5 groups), and octahedral (6 groups). Lone pairs modify these into bent, T-shaped, seesaw, square planar, etc.