In the first class, we reviewed last class 'content which were relative atomic mass and relative formula mass.

第一节课首先回顾了一下相对原子质量，相对分子质量的定义及计算方法。

youdao

In the first class, we reviewed last class 'content which were relative atomic mass and relative formula mass.

第一节课首先回顾了一下相对原子质量，相对分子质量的定义及计算方法。

youdao