molecules, i.e., the science of organic synthesis partial positive partial negative Increased electron density associated with the electronegative ch Ionic structures are often represented using Lewis dot formulas, in which the electrons in the outer shell are shown as paired or unpaired dots surrounding the atomic symbol. Covalent bonds can likewise be shown using dot formulas and these are often useful. The large number of bonds in a typical organic molecule, however, would make drawing lewis dot structures somewhat tedious and covalent bonds are typically represented as a single line connecting the two atoms. When it is desirable, polarization along a covalent bond can be shown in these structures by using the symbols 8+ and8- over the atoms in question, as shown below. se Cl Cl Cl 8 Cl: Cl: C: Cl: C1-C-Cl &eCI-C-C18e Cl: se 教学手段与方法:课堂讲授多媒体教学 思考题、讨论题、作业: Homeworks;Page312,313,3.14,3.15,3.17,3.18.3.23, 3.24. 参考资料(含参考书、文献等) 1. Solomons, Organic Chemistry, fifth adition 2. Oxford; Organic Chemistr 3.北京大学,有机化学 4.南京大学,有机化学,(上,下) 5.邢其毅,有机化学,(上,下) 注:1、每项页面大小可自行添减;2一次课为一个教案;3、“重点"、“难点"、“教学手段molecules, i.e., the science of organic synthesis. Ionic structures are often represented using Lewis dot formulas, in which the electrons in the outer shell are shown as paired or unpaired "dots" surrounding the atomic symbol. Covalent bonds can likewise be shown using dot formulas, and these are often useful. The large number of bonds in a typical organic molecule, however, would make drawing Lewis dot structures somewhat tedious, and covalent bonds are typically represented as a single line connecting the two atoms. When it is desirable, polarization along a covalent bond can be shown in these structures by using the symbols "+" and "-" over the atoms in question, as shown below. 教学手段与方法：课堂讲授.多媒体教学。 思考题、讨论题、作业：Homeworks;Page.3.12, 3.13, 3.14, 3.15, 3.17, 3.18.3.23, 3.24. 参考资料（含参考书、文献等）： 1. Solomons, Organic Chemistry, fifth adition 2. Oxford; Organic Chemistry 3. 北京大学， 有机化学 4．南京大学， 有机化学，（上，下） 5．邢其毅，有机化学， （上，下） 注：1、每项页面大小可自行添减；2 一次课为一个教案；3、“重点”、“难点”、“教学手段