I mean they take up a teeny bit but essentially when we're thinking about the set up of the atom, we don't have to account for them as using up a lot of the mass we're discussing.

所以我们可以假设电子没有质量,它们占据了，非常小的一部分,所以当我们考虑,原子的构造的时候,不用考虑它们的质量。

麻省理工公开课 - 化学原理课程节选

We figured out the mass is so tiny that it shouldn't really deflect them very much.

电子的质量这么小,对它基本不会产生影响。

麻省理工公开课 - 化学原理课程节选

If you knew this was one kilogram, then the acceleration of the elephant, which will be some tiny number, maybe 100th of what this guy did; the mass of the elephant is then 100 kilograms.

如果已知这个物体的质量为 1 千克,那大象的加速度,会是一个比较小的数,可能是物体加速度的 1 / 100,大象的质量就是 100 千克

耶鲁公开课 - 基础物理课程节选

If we think of the size of a typical atom, we would say that would be about 10 to the negative 10 meters. So, we can see the diameter of a nucleus is absolutely smaller really concentrating that mass into a very small space.

一个普通细胞的大小，抱歉，我和细胞核搞混了0,如果我们考虑，一个普通原子的大小,这大概是10的负十次方米,所以原子核的直径确实非常小,真的是把质量。

麻省理工公开课 - 化学原理课程节选

PROFESSOR: Much, much smaller the positive particle.

教授：非常非常小,比起正电粒子的质量。

麻省理工公开课 - 化学原理课程节选

that the negative particle travelled - it was deflected much, much further by those plates, what he could also assume and make the conclusion of is that the mass of that negative particle is actually larger or smaller?

因为他发现负电粒子,运动了很远,它被两块电板偏转了,非常非常远,所以他给出的结论是,负电粒子的质量,是比较大还是比较小？

麻省理工公开课 - 化学原理课程节选

But he also realized that when they did hit something what they hit what unbelievably massive but also that that mass was concentrated So eventually, this is what we have come to call the nucleus of an atom.

碰到的一定是十分重的东西,而且那些质量,要聚集在非常非常小的空间内,这个就是我们称作,原子核的东西。

麻省理工公开课 - 化学原理课程节选