大学化学 >> 2019, Vol. 34 >> Issue (12): 22-28.doi: 10.3866/PKU.DXHX201912033

所属专题: 2019元素周期表年

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原子量之“变”

王颖霞*(),周公度   

  • 收稿日期:2019-12-09 录用日期:2019-12-11 发布日期:2019-12-13
  • 通讯作者: 王颖霞 E-mail:yxwang@pku.edu.cn
  • 作者简介:王颖霞,女,博士。北京大学化学与分子工程学院教授,博士生导师。主讲"普通化学""无机化学""多晶X射线衍射"等课程,参与了《普通化学原理》《晶体和准晶体的衍射》《元素周期表和元素知识集萃》等书籍的编写工作。主要从事无机固体化合物的合成、结构与性能的研究工作,学术专长是利用X射线衍射结合电子衍射、中子衍射数据解析晶体结构。2002年,获教育部"霍英东青年教师教学优秀奖"; 2009年,作为教学骨干之一,所在"普通和无机化学"教学团队获"国家级优秀教学团队"。现任《大学化学》主编

"Changes" of Atomic Weights

Yingxia WANG*(),Gongdu ZHOU   

  • Received:2019-12-09 Accepted:2019-12-11 Published:2019-12-13
  • Contact: Yingxia WANG E-mail:yxwang@pku.edu.cn

摘要:

原子量是最为基础的科学概念之一,"国际纯粹与应用化学联合会(IUPAC)"之"同位素丰度和原子量委员会(CIAAW)"每两年会修订并发布一次原子量。自2009年起,IUPAC宣布某些元素的原子量不再是常数,这些元素的标准原子量为区间值。为方便使用,对于这些元素,给出一个合理的单一数值,称为常规原子量。何为标准原子量?何为常规原子量?为何某些元素的原子量出现区间值?依据原子量数值的特性,元素可以分为几大类?本文在介绍最新元素周期表中原子量的特点之后,简述原子量测定、标准确定、概念演变的发展历史,讨论原子量的修订与变化等问题。

关键词: 原子量, 标准原子量, 常规原子量, 同位素丰度, 原子量区间, 原子质量单位

Abstract:

Atomic weight is one of the fundamental scientific concepts. "The IUPAC Commission on the Isotopic Abundances and Atomic Weights" revises and releases atomic weights of the elements every two years. Since 2009, IUPAC announced that the atomic weights of some elements are no longer constants of nature, and the standard atomic weights of these elements span an interval. For the convenience of users, a single value is also provided for these elements, which is called "conventional atomic weight". What is the standard atomic weight? What is a conventional atomic weight? Why do the atomic weights of some elements span an interval? According to the characteristics of atomic weight values, how many classes can the elements be divided into? After introducing the characteristics of atomic weights in the latest periodic table of the elements, this article briefly deals with the history of atomic weight determination, the development of the standard of the unified atomic mass unit, and then discusses the revision and changes of atomic weights.

Key words: Atomic weight, Standard atomic weight, Conventional atomic weight, Isotope abundance, Atomic weight interval, Atomic mass unit

MSC2000: 

  • G64