Versus looking at, for example, helium or neon or argon, these are all inert gases, inert meaning essentially do not react, those were grouped together in the periodic table.

相反，他发现氦，氖，氩，都是惰性气体，惰性的意思是基本不参与化学反应，因此把它们放在周期表中的同一类里。

麻省理工公开课 - 化学原理课程节选