我们知道,碳原子的最外层有四个电子,它能与四个原子(原子团,包括碳原子)形成四个单共价键,这个原理一般称之为碳“四价”原理(也叫碳饱和原理),这一原理在有机化学中应用得比较广泛。【例l】下面是苯和一组稠环芳香烃结构简式(’98高考测试题) We know that the outermost layer of carbon atoms has four electrons, which can form four single covalent bonds with four atoms (atomic groups, including carbon atoms). This principle is generally called the principle of carbon “quadruple” (also called carbon). Carbon saturation principle) This principle is widely used in organic chemistry. [Example 1] The following is a simplified structure of benzene and a group of fused aromatic rings (’98 college entrance examination questions)