So if I tell you that the energy for single hydrogen atom is negative 13 12 kilojoules per mole.
如果我告诉大家单个氢原子的能量,是负的,1312,千焦每摩尔。
And that means radiation of energy, and that energy has to come from inside the atom itself.
意味着有能量的辐射,这些能量来自于原子本身。
So, what we get for the disassociation energy for a hydrogen atom is 424 kilojoules per mole.
因此,我们就得到了氢原子,离解能的大小为,424,千焦每摩尔。
So when we talk about orbitals in multi-electron atoms, they're actually lower in energy than the corresponding h atom orbitals.
它们的能量实际上,比对应的氢,原子轨道要低。
We're going to be looking at the solutions to the Schrodinger equation for a hydrogen atom, and specifically we'll be looking at the binding energy of the electron to the nucleus.
我们将研究下氢原子薛定谔方程的解,特别是电子和核子的结合能,我们将研究这部分。
That energy will be absorbed by the hydrogen atom, n=1 the electron will rise from n equals one n=2 to n equals two.
这能量将会被氢原子吸收,这个电子会从,上升到。
So a plus two ion means that we're removing two electrons from the atom and the electrons that we're going to remove are always going to be the highest energy electrons.
一个2价正离子,我们要移除的两个电子,我们要移除的两个电子,将会是,最高能量的电子。
And even though he could figure out that this wasn't possible, he still used this as a starting point, and what he did know was that these energy levels that were within hydrogen atom were quantized.
这是不可能的了,但他还是以此为出发点,他知道,氢原子的这些能级,是量子化的,而且他也知道,我们上节课所看到现象。
But, in fact, we can also talk about the ionization energy of different states of the hydrogen atom or of any atom.
但实际上我们也可以讨论氢原子,或者其它任何原子的其它能级的电离能。
The first that we need to know the energy of the photon that's incident on our gaseous atom.
首先,我们需要知道,入射到气体原子的光子的能量。
If we know that this is it the dissociation energy for a hydrogen atom, we can also say the bond strength for hydrogen molecule 424 is 424.
如果我们知道了这是一个氢分子的离解能,那么我们也可以说氢分子的键的强度,就是。
What we've learned so far is as a first approximation, what we want to do is put the atom with the lowest ionization energy in the middle here.
我们之前所学的可以作为第一近似,我们要做的是把电离能,最低的原子放在中间。
And it should make sense where we got this from, because we know that the binding energy, if we're talking about a hydrogen atom, what is the binding energy equal to?
很容易理解,我们怎么得到这个的,因为我们知道,结合能,如果,对氢原子来说,结合能等于什么?
The first ionization energy of lithium is about 5.4 electron volts per atom.
锂的一级电离能,大约是每原子5。4电子伏。
In terms of picking a Lewis structure that's going to be the lowest energy, what you want to do is put the atom with the lowest ionization energy in the center of your atom.
为了挑选一个具有,最低能量的路易斯结构,你需要把电离能最低的原子,放在最当中的位置。
So, for example, in a hydrogen atom, if you take the binding energy, the negative of that is going to be how much energy you have to put in to ionize the hydrogen atom.
例如在氢原子里面,如果你取一个结合能,它的负数就是。
So, we see that the two h atoms separate have a certain energy that's lower than when the electron's not with the atom.
那么,我们看到两个分开的氢原子所具有的能量,比原子中没有电子时更低。
So if we can figure out the binding energy, we can also figure out how much energy we have to put into our atom in order to a eject or ionize an electron.
所以如果我们可以计算出结合能,我们也可以计算出,我们需要注入多少能量到原子中,去逐出或电离一个电子。
So we should be able to calculate a z effective for any atom that we want to talk about, as long as we know what that ionization energy is.
我们应该可以计算出任何一个,我们想要谈论的原子的有效电荷量,只要我们知道电离能是多少。
We can also look at the energy equation now for a multi-electron atom.
我们也可以看到现在对于,一个多电子原子的能量方程。
So, what he did was kind of impose a quantum mechanical model, not a full one, just the idea that those energy levels were quantized on to the classical picture of an atom that has a discreet orbit.
还不是完整的,只是这些能级,是量子化的概念,作用到原子有分立轨道的经典原子模型上,当他做了一些计算后,他得到有个半径,他算出来。
So, in fact, yes, we did confirm that these covalent bond, at least in the case of hydrogen, we have confirmed by the numbers that we are at a lower energy state when we talk about the bonded atom versus the individual atom.
因此,事实上,是的,我们证实了共价键,至少在氢这种情况下,我们通过数据证实了,成键的原子处于能量更低的状态,当其与单个的原子相对比时。
and he knew this the same way that we saw it in the last class, which is when we viewed the difference spectra coming out from the hydrogen, and we also did it for neon, but we saw in the hydrogen atom that it was very discreet energy levels that we could observe.
那就是,当我们看氢原子发出的光谱时,我们也看了氖气,但我们看到,氢原子能级是分立的,这些,在当时,已经被观察到了,他也都知道。
So, in talking about covalent bonds, we should be able to still apply a more general definition of a chemical bond, which should tell us that the h 2 molecule is going to be lower in energy than if we looked at 2 separate hydrogen atom molecules.
那么,既然提到了共价键,我们应该还可以,给化学键下一个更普遍的定义,那就是告诉我们氢分子能量应该更低,与两个分开的氢的单原子分子相比。
So, thinking about ionization energy, which atom would you put in the middle here?
那么,从电离能的角度考虑,大家会把哪个原子放在中间?
Now this is a good place to start, because we are very familiar with ionization energy, we've been talking about it it's that minimum energy required to remove an electron from an atom.
现在这是一个开始下面内容的好地方,因为我们已经很熟悉电离能了,我们从很久以前就一直在讨论,它是从一个原子中,拿走一个电子所需要消耗的最低能量。
And we can look at precisely why that is by looking at the equations for the energy levels for a hydrogen atom versus the multi-electron atom. So, for a hydrogen atom, and actually for any one electron atom at all, this is our energy or our binding energy.
而且我们可以精确地看看,为什么是这样的,通过看对于氢原子和,多电子原子能级的方程所以对于氢原子,事实上对于任何一个电子,这是我们的能量或者我们的结合能。
We've got a lot of constants in this solution to the hydrogen atom, and we know what most of these mean. But remember that this whole term in green here is what is going to be equal to that binding energy between the nucleus of a hydrogen atom and the electron.
在这个解中有很多常数,其中大部分我们,都知道它们代表的意思,但记住是这整个绿色的部分,等于核子和电子的结合能。
So, let's take a look here at an example of an energy diagram for the hydrogen atom, and we can also look at a energy diagram for a multi-electron atom, and this is just a generic one here, so I haven't actually listed energy numbers, but I want you to see the trend.
所以让我们来看看,一个例子氢原子的能量图,我们也可看看一个,多电子原子的能量图,这是一个普通的图谱,我没有列出能量的数字,但是我想让你们看这个趋势。
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