9.2 VSEPR theory of atoms of lone bonded to pairs on Arrangement of Molecular Class central atom central atom electron pairs Geometry AB 4 0 tetrahedral tetrahedral B 109.5° Methane CHa B B 109.5° TetrahedralClass # of atoms bonded to central atom # of lone pairs on central atom Arrangement of electron pairs Molecular Geometry AB4 4 0 tetrahedral tetrahedral Methane CH 9.2 VSEPR theory Methane CH4