-
When a light particle,or photon, hits an electron, the electron jumps to a higher energy state.
VOA: special.2010.09.01
-
No, OK and that's correct, because each photon of light actually has more energy than is needed to eject an electron.
没有，好，对了，因为每一个光子实际上,都有更多的能量去逐出一个电子。
-
And instead of having the electron giving off energy as a photon, instead now the electron is going to take in energy from light and move up to that higher level.
与电子以光子形式施放能量不同,我们现在要从光中,获得能量到一个更高的能级。
-
These are photodetectors, band gap two electron volts, respond to visible light.
这是光电探测器，能带隙为2电子伏，当它反应于可见光。
-
So, for example, we were talking about a threshold frequency as in a minimum frequency of light that you need in order to eject an electron from a metal surface.
举个例子来说，我们谈论的临界频率是,光从金属表面逐出一个电子,所需的最小频率。
-
The electron is not moving at the speed of light.
电子不是以光速运动的。
-
So, for example, here we're showing rubidium and potassium and sodium plotted where we're plotting the frequency -- that's the frequency of that light that's coming into the metal versus the kinetic energy of the electron that's ejected from the surface of the metal.
让大家看来都是可以理解的事情,就是把不同金属的观测结果,画到一张图里面来，例如这里,我们展示的是钠，钾,铷的频率-这是照射金属的光的频率,和金属表面出射电子动能的关系。
-
c We know it's very specific for light because in this equation is c, the speed of light. So any time you go to use this equation, if you're trying to use it for an electron, just ask yourself first, does an electron travel at the speed of light?
我们知道它只对光适用是因为在这个方程里有,光速，所以下次你们用这个方程前，如果你们要把它用到一个电子上，先问问你自己，电子的运动速度是光速吗？
-
So, one thing they did, because it was so easy to measure kinetic energy of electrons, is plot the frequency of the light against the kinetic energy of the electron that's coming off here. And in your notes and on these slides here, just for your reference, I'm just pointing out what's going to be predicted from classical physics.
他们做的其中一件事,因为测量电子动能是很容易的，就是画出光的频率,和出射电子动能之间的关系,在讲义的这里，仅仅是,为了做个比较，我要指出，经典物理所给出的预测,这个不作为对你们的要求。
-
We give you a very rich table of constants that's got all kinds of things from the mass of the electron to the speed of light, and all this stuff to the requisite number of significant figures. And, in addition, you are allowed to take in one sheet of paper, 8 1/2 x 11 one sheet 8 1/2 x 11, you can write anything you want on it.
我们会给你一个很详实的常量表,将会涉及很多方面，从元素的电子,到光速，这些内容到有效数字的定量,还有，你们可以带来一张纸，纸的规格是，可以写任何你们想写的东西。
-
Well, we can't guarantee with UV light we'll have enough energy to eject every single electron, so that's why when we use x-rays, they're higher energy, you can pretty much be guaranteed we're going to eject all of those electrons there.
好，我们不能保证紫外光有足够的能量,激发出每一个电子，所以我们要使用，X，射线，它的能量更高，你可以非常确定,我们可以激发出其中所有的电子。
应用推荐