知识贝壳
知识贝壳
所属栏目：英汉双解化学
The ob-servation that,when the elements are ar-ranged in order of increasing relative atom-ic mass (atomic weight),there is a similar-ity between members that are eight ele-ments apart (inclusive).For example,lithiumhas similarities to sodium,beryllium to ......（本文共 554 字 ） [阅读本文] >>