论文部分内容阅读
元素只论种类,不讲个数;元素可以以单质和化合物两种形态存在;元素分为金属元素(最外层电子数<4)、非金属元素(最外层电子数≥4,氢为1)、稀有气体元素(最外层电子数=8,He为2)。元素的化学性质与其原子的核外电子排布,特别是最外层电子数有密切关系;而元素的种类,取决于其原子的质子数(或核电荷数)。元素符号表示一种元素,表示这种元素的1个原子;金属元素、稀有气体元素、大多数固态非金属元素的元素符号还表示由该元素形成的单质。
Elemental can be two kinds of elements and compounds exist; elements are divided into metal elements (the outermost electron number <4), non-metallic elements (the outermost electron number ≥ 4, hydrogen is 1), rare gas element (outermost electron number = 8, He = 2). The chemical nature of the element is closely related to the extranuclear electron arrangement of its atoms, especially the outermost electron number; the type of element depends on the proton number (or nuclear charge number) of its atoms. The symbol of the element represents an element representing one atom of the element; the elemental symbols of the metal element, the rare gas element, and most of the solid non-metal elements also represent the elemental substance formed by the element.