众所周知,化学元素性质的周期性取决于元素原子电子层结构的周期性。通常为了说明元素物理和化学性质的周期性变化规律,将各元素性质的数值对已知的全部元素原子序数作曲线,能够清楚地看出元素性质的周期性变化规律。但是这种周期性的描述,对于周期系中同族元素性质的周期性揭示得不够。而且现行教材一般着重周期表中横的方向元素性质的周期性变化,讨论到纵的元素系列往往将碱金属、碱土金属及卤素作为例证,旨在说明同族元素性质随原子序数增加的顺序逐渐增加或减 It is well known that the periodicity of the nature of a chemical element depends on the periodicity of the electron structure of the element’s atomic electron. Generally, in order to explain the periodical variation of the physical and chemical properties of elements, the values ​​of the properties of each element are plotted against the known atomic number of all elements, and the periodical variation of the nature of elements can be clearly seen. However, this periodic description does not reveal enough about the periodic nature of the elements of the same family in the periodic system. In addition, current textbooks generally emphasize periodic changes in the nature of the elements in the transverse direction of the periodic table. Discussions of the vertical element series often include alkali metals, alkaline earth metals, and halogens as examples, aiming to show that the order of the nature of the same group elements increases with increasing atomic number. Or minus