-
So, it turns out that we have zero nodes that we're dealing with when we're talking about a 3 d orbital.
所以结果是,３ｄ轨道没有节点。
-
It might not have any electrons in it, but it still exists, so you need to draw these into your molecular orbital diagram.
也许它里面没有电子，但它是存在的，所以你需要在分子轨道图里画出来。
-
All right. So, today we're going to be talking about molecular orbital theory, but first I wanted to just mention, in case some of you didn't hear what the Nobel Prize was this morning, and this was in chemistry, it went to three different chemists.
好的，今天我们要讲的是,分子轨道理论，但首先我要说，以免有些同学没有听到,今天早上的诺贝尔奖，这是化学奖，它颁给了3个不同的化学家。
-
So if we draw the 2 p orbital, what we just figured out was there should be zero radial nodes, so that's what we see here.
如果我们画一个２ｐ轨道，我们刚才知道了是没有径向节点的，我们在这可以看到。
-
So what we're doing is filling in those eight electrons following the Aufbau principle, so our first electron is 1s going to go in the 1 s, and then we have no other options for other orbitals that are at that same energy, 1s so we put the second electron in the 1 s as well.
它会是什么样子呢,我们正在做的是将这8个电子按照奥弗,堡原理进行填充,所以我们第一个电子将会进入，然后我们没有其他的,轨道的选择在同一个能级，所以我们把第二个电子也放入。
-
Remember, we didn't hybridize the 2 p y orbital, so that's what we have left over to form these pi bonds.
记住，我们并没有杂化2py轨道，这是我们剩下的那个行成了π键。
-
Yup, zero radial nodes. So, for a 2 p orbital, all the nodes actually turn out to be angular nodes.
没有，对于2p轨道，所有的节点都是角向节点。
-
There's no more 2 p orbitals to put it into, so we're going to actually have to double up.
现在并没有多余的2，p，轨道来放它，我们只能在其中一个，2，p，轨道上放上两个。
-
And it turns out that if we're talking about a 2 s orbital in an ion, that means it doesn't have as many electrons in it, so what we're going to see is less shielding.
结果是当我们讨论,一个离子中的，2，s，轨道的时候，这意味着里面没有多的电子，那么电子的屏蔽效应会更小。
-
It doesn't actually have an electron in it, so we don't have to worry about whether it's very high in energy or not, we don't care that it's high in energy.
你也许会想，为什么我们不杂化这个2py轨道,它里面没有电子，所以我们不用管它的能量。
-
But in sigma orbitals, you have no nodal planes along the bond axis, so if we had a nodal plane here, we'd see an area where the wave function was equal to zero.
但在sigma轨道里，沿着轴向是没有节点平面的，如果我们有个节点，我们就会看到某个地方波函数等于0。
-
So we want to look at any element that has a 3 p orbital filled, but that does not then go on and have a 4 s, because if it had the 4 s filled then we would actually see six lines in the spectrum.
所以，我们要找一找有哪些元素的,3，p，轨道被占据，但没有，4，s，轨道被占据,因为如果，4，s，轨道也被占据了,那我们会在光谱中看到第六条谱线。
-
So we end up with 1 p orbital completely untouched, and three hybrid s p 2 orbitals.
没有变化，所以我们得到的是1个完全没有变化p轨道。
-
But keep in mind sigma orbitals have no nodal planes along the bond axis.
但记住sigma轨道沿着,键轴方向是没有节点的。
-
So again, we can name these molecular orbitals and these we're going to call also to point out there is now a bond axis along this nodal plane, which is something we didn't see before when we were combining the s orbitals.
同样的，我们可以,命名这些分子轨道,这些轨道叫做-同样要指出的是,现在沿着键轴是一个节点面，这是我们讨论s轨道的时候,从没有看到过的。
-
But we haven't yet addressed why, for example, a 2 s orbital islower in energy than the 2 p orbital, or why, for example, a 3 s orbital is lower in energy than a 3 p, which in turn is lower than a 3 d orbital.
但是我们还没有强调为什么，举个例子一个2s轨道能量低于2p轨道,或者为什么，举例来说它依次低于3d轨道,屏蔽一个3s轨道的能量小于3p轨道。
-
Keep in mind we do have this p orbital here and it's coming right out at us. And this p orbital is here, but it's empty, it doesn't have any electrons in it, that's why we don't have to worry about it in terms of getting our electrons as far away from each other as possible.
他们程120度角互相远离,这样它们离得最远，记住我们这里确实有个p轨道，它朝向我们，这里有个p轨道，但它是空的,里面没有电子,这就是为什么我们在考虑。
-
But it doesn't actually cost as much energy as you might think, because in this s orbital here we have a paired electron situation where we're moving up to a p orbital where the electron is no longer paired, so it won't feel quite as much electron repulsion, but nonetheless, this is going to cost us energy.
但它消耗的并没有,你们想象的那么多,因为s轨道里我们电子是配对的,当我们把，电子移到p轨道,电子不再配对，所以它不会感受到那么多的电子排斥，但尽管如此，这个过程还是要消耗能量的。
应用推荐