So you can either say that electrons are very, very tiny or that they're never ending, and both are pretty accurate ways to think about what an atom is.

所以你既可以说,原子非常非常小,也可以说它是不会终止的，这两种说法,都是正确的。

麻省理工公开课 - 化学原理课程节选

So, this is really small, this is undetectably small.

所以，它非常的小，无法察觉的小。

麻省理工公开课 - 化学原理课程节选

But the fact is there are trace, trace amounts.

但事实是它的含量非常，非常小。

麻省理工公开课 - 化学原理课程节选

So, what we can do to actually get a probability instead of a probability density that we're talking about is to take the wave function squared, which we know is probability density, and multiply it by the volume of that very, very thin spherical shell that we're talking about at distance r.

我们能得到一个概率,而不是概率密度的方法,就是取波函数的平方，也就是概率密度，然后把它乘以一个在ｒ处的,非常非常小的,壳层体积。

麻省理工公开课 - 化学原理课程节选