原子的种类(How Atoms Differ)质子数,中子 2023年8月17日 · 同位素符号,用质量数标识,质量数=质子数+中子数。 For example, copper has two isotopes. The isotope with 29 protons and 34 neutrons has a mass number of 63 (29 + 34 = 63), and is called copper-63 (also written 更多内容请查看https://zhuanlan.zhihu.com/p/650514413