So similarly, as we now move up only one more atom in the table, 3 so to an atomic number of three or lithium, now we're going from six variables all the way to nine variables.

类似地就像我们现在,移动到周期表中仅仅多一个电子的情况，移动到一个原子数为，或者锂元素,现在我们从6个变量到了9个变量。

麻省理工公开课 - 化学原理课程节选

Because it was in the 1950's or so, maybe the late 1940's, that people started to discover lithium, even though it had no natural function, it did do something in our bodies.

因为在二十世纪五十年代左右，可能是四十年代末期，人们开始发现锂，尽管不参与人体的正常生理活动，但是它确实会对我们的身体产生影响。

麻省理工公开课 - 化学原理课程节选