9.1 Molecular Geometry/Shapes 分子构型 The shape of a molecule determines its odor,taste and actions as a drug.It governs the reactions that take place throughout our bodies. Melting point 熔点 Boiling point 沸点 :olecular geometry→structure→properties density 密度 结构 性质 solubility 溶解度 reactivity... 反应性 Valence Shape of molecules can be Shell predicted by the VSEPR VSEPR Electron theory 价层电 Pair 子对互 斥理论 Repulsion
9.1 Molecular Geometry/Shapes The shape of a molecule determines its odor, taste and actions as a drug. It governs the reactions that take place throughout our bodies. int int Melting po B Molecular geo oiling po metry structure properties density → → 分子构型 熔点 沸点 密度 Shape of molecules can be predicted by the VSEPR theory lub ... Molecular geo density so ility structure reactivit metr prope y y → → rties alence hell lectron air epulsion V S VSEPR E P R 价层电 子对互 斥理论 密度 溶解度 反应性 结构 性质
9.2 Valence Shell Electron Pair Repulsion (VSEPR)theory imt0redicttheshapeofaaoleule2 a)The valence electrons repel each other 成键电子 Bonding electrons Valence electrons of Central Atom 价电子 Non-bonding electrons 非键电子 (Lone-pair electrons) 孤对电子 b)The molecule adopts whichever 3D geometry to minimize this repulsion. 构型 Valence electrons staying as far apart as possible!
9.2 Valence Shell Electron Pair Repulsion (VSEPR) theory a) The valence electrons repel each other Bonding electrons 成键电子 - Bonding electro Valence ele ns Non bon ctrons din of Ce g elec nt tr r o al Atom ns b) The molecule adopts whichever 3D geometry to minimize this repulsion. Valence electrons staying as far apart as possible! 价电子 非键电子 (Lone-pair electrons) 孤对电子 构型
9.2 VSEPR theory 1)Lewis Structure 过一Be—: 2)Number of valence electrons Be:1s22s2 2 pairs of valence electrons around a central atom Beryllium Chloride (BeCl Bond angle 180° 键角 linear 直线型
9.2 VSEPR theory pairs of around val a 2 ence ele a ctron t s central om 1) Lewis Structure Cl Be Cl 2) Number of valence electrons 2 2 4Be s :1 2s a central atom Beryllium Chloride (BeCl2) linear Bond angle 直线型 键角
9.2 VSEPR theory of atoms of lone 分子构型 bonded to pairs on Arrangement of Molecular Class central atom central atom electron pairs Geometry AB2 2 0 linear linear 线型 180° 180° :6A BA .B Beryllium Chloride BeCl 180°
AB2 2 0 Class # of atoms bonded to central atom # of lone pairs on central atom Arrangement of electron pairs Molecular Geometry linear linear B B 9.2 VSEPR theory 线型 分子构型 B B Beryllium Chloride BeCl2
9.2 VSEPR theory of atoms of lone 分子构型 bonded to pairs on Arrangement of Molecular Class central atom central atom electron pairs Geometry AB3 3 0 trigonal trigonal planar plauar 120° Boron Trifluoride(BF3 平面三角形 平面三角形 20o sB:1s22s22p Planar
Class # of atoms bonded to central atom # of lone pairs on central atom Arrangement of electron pairs Molecular Geometry AB3 3 0 trigonal planar trigonal planar Boron Trifluoride (BF ) 9.2 VSEPR theory 分子构型 Boron Trifluoride (BF3) 平面三角形 平面三角形 2 2 1 5B :1s 2s p 2