So for the reversible process, the work done is the integral under the pressure volume state function, the function of state.
对可逆过程,做的功,是压强体积态函数曲线下,的积分面积。
Gas phase single atom. So we don't have to deal with work function or any kind of energies associated with some condensed form of matter.
气相的单原子,所以我们不需要再,处理功函数的问题,以及和凝聚态相关的能量问题。
Sometimes we might just directly tell you that's probably the easiest scenario, because when we think about work functions those are usually reported in energy.
有时候我们可能只是直接告诉你,那可能是最简单的情况,因为当我们考虑功函数时,它们经常用能量来记录。
And I also want to introduce one new function.
热量和功,我还要引入一个新函数。
So, we do this here for the photoelectric effect, and in terms of the photoelectric effect, what we know the important point is that the incoming photon has to be equal or greater in energy then the work function of the metal.
所以,我们做这个是为了说明,光电效应,在光电效应方面,我们知道的最重要的事情,就是入射的光子能量必须等于,或者大于金属的功函数。
So if we think about the work function for zinc, and the work function for zinc is 6.9 times 10 to the -19 joules, do we expect that when we shine our UV light on the zinc, we'll be able to eject electrons?
如果我们考虑锌的功函数,它是6,9乘以10的-19次方焦耳,我们是否可以预测当,用紫外灯照射锌时,我们可以射出电子呢?
When we talked about the photoelectric effect, that was called the work function.
如果我们在研究光电效应,这被称为功函数。
So, now we can talk about it in different terms, Ei for example, talking about e sub i, which is the incident energy or the energy of the light that comes in, or talking about work function here, and that's just another way to say threshold energy.
现在我们可以从不同的方面,来谈论它了,举例来说,它是入射能量或者进来的光的能量,或者谈论这里的功函数,它是另一种描述临界能量的方式。
We can also talk about it in terms of if we want to solve, if we, for example, we want to find out what that initial energy was, we can just rearrange our equation, or we can look at this here where the initial energy is equal to kinetic energy plus the work function.
初始能量是多少,也可以,写成另一种形式,我们可以把方程变形,或者我们看这里,初始能量等于,动能加功函数。
There's no change in them, and then we also looked at some at non-state functions, work and heat, and saw that those aren't zero going around a cycle. Of course you can do work in a cyclic process, and heat can be exchanged with the environment at the same time.
它们不会有变化,然后我们研究了,一些非态函数,功和热量,并看到,沿着循环行进一周的话,它们并不是零,当然你可以在,一个循环过程中做功,而同时热量可以在系统,与外界环境之间进行交换。
So, therefore, we can rewrite our equation in two ways. One is just talking about it in terms only of energy where our kinetic energy here is going to be equal to the total energy going in -- the energy initial minus this energy of the work function here.
所以我们可以把方程,写成两种形式,一个是,只考虑能量,动能等于总的,入射能量-初始能量减去,功函数的能量,我们如果想解决,比方说,我们想知道。
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?
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