01 元素和元素周期表 The number of protons in the nucleus of an atom is referred to as the atomic number, or proton number, Z. The number of electrons in an electrically neutral atom is also equal to the atomic number, Z. The total mass of an atom is determined very nearly by the total number of protons and neutrons in its nucleus. This total is called the mass number, A. The number of neutrons in an atom, the neutron number, is given by the quantity A-Z. 原子核内的质子数被称为原子序数,或质子数，Z。一个电中性原子的电子数量也等于原子序数，Z。原子的总质量接近核内质子数和中子数之和。这个总数被称为质量数A。中子在一个原子中的数量,中子数,给出了的数量为A-Z。 The term element refers to, a pure substance with atoms all of a single kind. To the chemist the "kind" of atom is specified by its atomic number, since this is the property that determines its chemical behavior. At present all the atoms from Z = 1 to Z = 107 are known; there are 107 chemical elements. Each chemical element has been given a name and a distinctive symbol. For most elements the symbol is simply the abbreviated form of the English name consisting of one or two letters, for example: 单质是指,一个纯物质由一种原子组成的。化学家认为这种原子由它的原子数决定,因为它的性质决定了其化学行为。目前所有被知道的原子是 Z = 1 到 Z = 107 的的原子，有 107 种化学元素。每一种化学元素被给以一个名字和一个独特的符号。对于大多数元素符号都仅仅是英文名称缩写为一个或两个字母,例如: oxygen==O nitrogen == N neon==Ne magnesium == Mg 氧=O 氮=N 氖=Ne 镁=Mg Some elements,which have been known for a long time,have symbols based on their Latin names, for example: 一些元素,很久以前就被知道的,它们的符号根据他们的拉丁名字符号,例如: iron==Fe(ferrum) copper==Cu(cuprum) lead==Pb(plumbum) 铁= =Fe(ferrum) 铜= =Cu(cuprum) 铅=...
