Molecular Shapes Lewis structures physical properties VSEPR (b.p., solubility) Molecular orbital theory Chemical reactivity Valence bond theory

Valence Bond Theory covalent bond overlap of orbitals bonding e- pair opposite spins CH4 geometry tetrahedral [He] 2s2 2p2 shape tetrahedral Pauling valence e- orbitals in molecules in atoms mix  produce molecular orbitals

sp3 mixing hybridization depends on number of atomic orbitals mixed type of atomic orbitals mixed CH4 need equivalent orbitals 4 mix atomic orbitals 4 [He] 2s2 2p2 mix s and 3 p sp3

sp3 CH4 hydrogen sigma bond [He] 2s2 2p2  bond sp3 p energy hybridization sp3 s CH4 hydrogen sigma bond [He] 2s2 2p2 s  bond sp3

PCl5 trigonal bipyramidal P Cl 5 hybridized orbitals 5 mix s + 3p + d dsp3

SF6 octahedral S F 6 hybridized orbitals 6 mix s + 3p + 2d d2sp3

sp2 formaldehyde CH2O C : H O 3 valence pairs on C 3 hybrid orbitals [He] 2s2 2p2 sp 2

sp2  -bond -bond : C H O p p energy hybridization sp2 s p p energy

sp CO2 C :: O : 2 hybridized bonds 2 unhybridized bonds s + p sp

sp C : :: C O -bond end-to-end -bond side-to-side O p p energy hybridization C sp s C :: O : -bond end-to-end -bond side-to-side p p energy hybridization O sp2 s