How does the structure of the community service program affect its perceived value? Is it part of academic study? Are there choices?
7 November 2016 Lecture Chapter 10 Molecular shapes, Valence bond theory, and MO theory ● VSEPR Theory ○ VSEPR = Valence Shell Electron Pair Repulsion ○ VSEPR allows you to predict the geometry of molecules. ○ Regions of electron density (called electron groups) orient around a central atom to get as far apart as possible. ● Molecular Geometry ○ Describe 3D shape of molecules using polygons and platonic solids ■ Central atom is in the center ■ Corners of the shapes are the surrounding atoms ○ ○ ● Electron groups ○ The geometry of a molecule is found by counting the electron groups on the central atom. Find the electron groups by drawing the lewis structure ■ Lone pairs ■ Single bonds ■ Multiple bonds ● Linear Geometry has two electron groups ○ Carbon Dioxide ■ ○ The central atom’s geometry tells a molecule’s shape. Do not need to consider the geometry of the outer atoms ● Trigonal Planar has three electron groups ○ Boron trifluoride ■ ● Tetrahedral has 4 electron groups ○ Methane ■ ● Tetrahedron ○ Pyramid with a triangular base ○ Imagine the atom inside the tetrahedron and the orbitals pointing to the vertices ● Trigonal Bipyramidal has 5 electron groups ○ PCl5 ● Octahedral has 6 electron groups ○ S
