以前(第五講)我們講元素週期表的時候,從週期表里面,可以看到元素的性質按排列的次序逐渐發生變化,尤其是元素的金属性質,隨着原子序數的增加,逐漸減弱,從顯著的金属性質,逐漸轉變到顯著的非金屬性質。並且變化是週期性的,到一定數目 Previously (fifth lecture) when we talked about the periodic table of elements, from the periodic table, we can see that the nature of the elements has gradually changed in the order of arrangement, especially the metal nature of the elements, gradually weakening as the atomic number increases. From the remarkable metal properties, it gradually changed to significant non-metallic properties. And the change is cyclical, to a certain number