And it was proposed by my thesis advisor Professor Weisskopf that we work on this problem to understand the effect of the impurities in scattering electrons and interfering with their motion.
VOA: special.2010.11.09
And Pauli says no two electrons in a given system can have the entire set of quantum numbers identical.
而泡利认为在一个给定的系统内,没有两个电子有完全相同的量子数。
The inner electrons are so tightly bound that they are for all intents and purposes, immobilized when it comes to reactivity.
内部电子被紧紧地束缚着,因此无论怎样,当进行反应时,它都是固定的。
OK, so we've got UV light here, and let's see what we can see, and we lose electrons, if that's what's happening.
好了,我们已经有了紫外光源,让我们来看看能观察到什么,如果那些事情发生了,我们将会失去电子。
OK, then it says draw a single bond from each surrounding atom to the central atom, and subtract two valence electrons.
后将中心原子与其相邻原子之间,连上单键,然后减掉2个价电子。
So, seven asks us if we have any valence electrons left, and how many valence electrons do we have left?
那么,第七步问我们是否还有价电子剩下,我们剩下了几个价电子?
So in terms of total numbers that we would need to complete our octets and fill our valence shells, we would need 18 electrons.
因此要填满我们的“八隅体“,排满所有的价壳层,我们总共需要十八个电子。
Each of these orbitals can have two electrons in them, so we get two electrons here, here, and here.
在每个轨道里面都有两个电子,所以我们有两个电子在这里,这里这里。
The positive force of attraction of the electrons on the outside is greater and greater, and that pulls everything in.
所以对外层电子的吸引力,会越来越强,把电子们都向内吸引。
So let's see, we started with 8 bonding electrons, and we used up only 4, so the answer is yes, we have 4 bonding electrons left.
那么让我们来看看,我们一开始有八个成键电子,然后只用掉了四个,因此答案应该是还有剩余,我们还剩下了四个成键电子。
All right, so the bonding order, you're correct, should be 2, if we subtract the number of bonding minus anti-bonding electrons and take that in 1/2.
好,你们是对的,键序为,如果我们用成键数,减去反键数除以2。
In terms of talking about the electrons, I wanted to point out that in the book and other places you might see electrons referred to as photoelectrons.
在谈到电子方面,我想指出在这本书,或者其他地方你可能会看到,电子被称为光电子。
For the carbon, we start with 4 valence electrons, we have 0 lone pair electrons minus 4, and we end up with a formal charge of 0.
对于碳,我们从四个价电子开始,我们有零个孤对电子,再减去四,最终我们有零个形式电荷。
So, shared electrons are the ones that are shared between the carbon and the nitrogen, so we have 6 shared electrons, and we want to take 1/2 of that.
共用电子是那些在碳和氮之间,被它们共用的电子,那么我们有六个共用电子,然后我们要给它乘上二分之一。
He introduced the concept of electronegativity which was a measure, therefore, it is quantitative, of the atom's ability to attract electrons within a covalent bond and developed a scale of electronegativity.
他引入了电负性这一概念,一个反映着原子在成共价键时吸引电子的能力的数据标度,因此这是数量上的,在共价电子中,电子原子能吸引电子,并发展为一定规模的电负性。
OK PROFESSOR: Valence electrons. OK, sometimes you're going to be asked to draw a molecular orbital diagram where you're asked to include all electrons, and sometimes it will specifically say only include valence electrons.
教授:价电子,有时候你画一幅分子轨道图,有时候要求你画出所有的电子,有时候特别要求,只包括价电子。
So in terms of nitrogen that starts off with a valence number of 5, again we have 2 lone pair electrons in the nitrogen, and again, we have 6 electrons that are shared.
对于氮来说,我们应该从五个价电子开始,同样,氮也有两个孤对电子,共用电子的个数也一样,是六个。
So the 3 s 1, or any of the other electrons that are in the outer-most shell, those are what we call our valence electrons, and those are where all the excitement happens.
它们是经常发生激发情况的,那也是我们所看到,我们称之为价电子,它们是经常发生激发情况的。
And the idea is that when you do these Lewis dot structures, we're representing electrons with dots, which we'll see in a minute, and each dot is going to represent a valence electron.
而当你遇到这些路易斯点结构时,我们会将电子用点来表示,我们马上就会看到,每个点都代表了一个价电子。
And the reason for this, and this is a very important point about the photoelectric effect, and the point here is that the electrons here are acting as particles, you can't just add those energies together.
这个现象的原因是,这是光电效应非常重要的一个论点,这个论点就是电子,在这里是粒子行为,你不能仅仅把这些能量加在一起。
So as we go down we're now adding electrons to further and further away shells, so what we're going to see is that the atomic radius is going to increase as we're going down the periodic table.
当我们向下走时,我们会将电子加在越来越远的壳层上,因此我们将看到原子半径,将随我们沿周期表向下走而增大。
So, the first thing we do is put two electrons between h and c, and then two electrons between c and n.
那么,我们先在氢和碳之间放两个电子,然后在碳和氮之间再放两个电子。
We also have six spots available to form hydrogen bonds, so we can go ahead and fill in those electrons as well.
我们还有6个地方可以供氢原子成键,我们可以继续把这些电子填充进去。
Clearly, we put 2 for each bond, and now we end up having 2 remaining bonding electrons left.
显然,我们在每个键处放上两个电子,那么最后我们还剩下两个成键电子。
And step seven is how many electrons do we have left over that are going to go into lone pairs? How many?
而第七步是我们剩下,多少电子成为孤对电子?多少?
So it's going to be favorable for the electrons instead to go to that lower energy state and be within the molecular orbital.
所以对于电子来说,更倾向于能量更低的轨道,呆在分子轨道里。
So we can put actually all 4 of our extra electrons in between the carbon and the nitrogen.
因此我们可以把这剩下的,四个电子都放在碳和氮之间。
So that's what we want to load up with electrons, and then see if we can remove some.
所以那个是我们,想加载电子的地方,然后看看我们是否可以移动一点。
And then we end up having 6 shared electrons, 2 from each of the bonds, so we end up with a formal charge on sulfur of plus 1.
然后我们有六个共用电子,每个键两个,因此最终硫的形式电荷量为正一。
He's trying to put eight electrons around helium, and it isn't working. But look down here.
他尝试把8个电子放在氦的周围,但那不行,但注意到这里。
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