Shape Sorter • The Rules 1) Nature loves symmetry! (bond lengths and angles) 2) Atoms or electrons like to be as far apart from each other as possible without disrupting the symmetry too drastically. 3) And, lone pairs take up more space because they are not confined by bonds.
3 BH3 NO2- 120o Electron pair geometry: Triangular planar Triangular planar Molecular geometry: Triangular planar Bent/Angular
Methane, Ammonia, Water 4 109.5 107.5 104.5 Electron pair geometry: Tetrahedral Tetrahedral Tetrahedral Molecular geometry : Tetrahedral Triangular pyramidal Bent/Angular Electron pair = nonbonding electrons + bonded atoms Molecular –only looks at shape of atoms; not lone pairs
5 Electron Pair Geometry: Triangular Bipyramidal SF4 PCl5 120 Seesaw 90 Triangular Bipyramidal BrF3 XeF2 Linear T-shaped
BrF5 6 Electron Pair Geometry: Octahedral SF6 90 Square Pyramidal Octahedral XeF4 Square Planar
Shape practice • ICl3 • CO2 • PBr3 • SeO3 Valence electrons Lewis Structure Electron pair geometry Molecular Geometry