Sometimes it's easier actually not touch it to the metal, -- I should have- TA: It's hard to see if it's moving or not.

有时候它更容易不接触金属，我本应该-,助教：很难看到它是否移动了。

麻省理工公开课 - 化学原理课程节选

So you don't have ductility, which is what you have in metal.

所以材料不具备延展性，而且金属中有自由电子。

麻省理工公开课 - 固态化学导论课程节选

now we're not just talking about 1 photon, 1/2 let's say we shoot them all at the same time at our metal, each of them having some energy that's let's say 1/2 the work function. So, just to take a little bit of an informal survey, who thinks here that we will have an electron that is ejected in this case?

我们现在不仅仅讨论一个光子，它们所具有的能量是功函数的，我们在同一时刻把它们打到金属上,我们做一个不太正式的调查,谁认为这种情况下,一个电子会被打出？

麻省理工公开课 - 化学原理课程节选