And so, for today, for example, it says Classification Schemes, Mendeleev, Atomic Structure, A Readings Chapter 1, Chapter 2, Appendix A.
今天,举个例子,讲的是分类法,门捷列夫,原子结构,阅读第1,第2章,和附录。
And one thing I want to tell you to start out with is something about this c h 3 group here.
有一点需要告诉大家的是,从这个一个碳原子和三个氢原子的组合开始。
That is why this says atomic number, but for most intents and purposes we can say this could be atomic mass.
那就是为什么这里说原子序数,但如果没有意图和目的,我们就说是原子质量。
It was developed before people knew about atoms and molecules.
它是在人们知道,原子和分子之前发展起来的。
So again you can see as we're filling up our molecular orbitals, we're using the exact same principle we used to fill up atomic orbitals.
当我们填充轨道的时候可以看到,我们用的是和,填充原子轨道一样的原则。
When it breaks this bond, that chlorine atom, a free chlorine atom comes down and reacts, this is ozone, with the ozone in the upper atmosphere.
当它打破这个化学键,氯原子,一个自由的氯原子下来,和在大气层的上方的臭氧反应,这就是臭氧,在大气上层有臭氧。
PROFESSOR: No. So, compared to the atoms, it should be somewhat the same energy, we shouldn't get any extra stabilization from forming the molecule.
不会,所以和原子相比,它的能量相同,形成分子并不会带来额外的稳定性。
He described the physical world as the integral of void plus being.
他将物理世界描述为,虚无和原子的总和。
So where we had left off with was we'd fully discussed up to the point of considering homonuclear diatomic molecules, so molecules that both have the same nucleus.
我们上次,讲到了我们,已经讨论过同核双原子分子,也就是有相同原子和的分子。
So, selenium 2 minus is what's going to be isoelectronic, because if you add two electrons to selenium, you'll get the same electron configuration that you have for krypton here.
负二价的硒离子将是等电子的,因为如果你给硒原子加上两个电子,你会得到,和氪原子相同的电子排布。
So in terms of the first step of skeletal structure, this is actually going to be easier because we don't have a central atom, we just have carbon and nitrogen here.
对于第一步画出骨架,其实比刚才更容易,因为我们没有一个中心原子,我们这里只有碳和氮两个原子。
So, why don't you go ahead and tell me, keeping that in mind, which atom in terms of h c or n would you expect to be in the center of hydrogen cyanide?
那么,请大家来告诉我,并且记住它,你认为氢,碳和氮中哪个原子,应该在氰化氢的中间呢?
Whereas in molecular orbital theory, what I'm telling you is instead we understand that the electrons are spread all over the molecule, they're not just associated with a single atom or a single bond.
而在分子轨道理论里,我要告诉你们的时,我们任为电子分布在整个分子中,它们不仅仅是和,一个原子或者一个键有关。
Further, the nucleus is assumed to be the seat of the essential part of the mass of the atom, and to have linear dimensions exceedingly small compared with the linear dimensions of the whole atom."
进一步的,核被认为是,原子主要质量所在的地方,和整个原子线性尺度相比,核具有很好的线性尺度“
So that should make sense, because we saw no energy difference between the actual atoms and the molecules.
这很好理解,因为我们看到,原子和分子的能量差为零。
It is about 10,000 to one, the ratio 10000 of the nuclear dimension to the entire atomic dimension.
原子核和整个原子的大小比例,约为1:
So, let's think of the energy of interaction when we're comparing atomic orbitals to molecular bonding orbitals.
当我们比较原子轨道和分子轨道的时候,我们来考虑一下相互作用能。
So, essentially you've got a positive ball which is identical to the size of the atom.
首先你要有一个和原子差不多大小的,带正电荷的球。
Benzene is a ring that's made up of six carbon atoms and six hydrogen atoms.
苯环是一个由六个碳原子,和六个氢原子组成的环。
If we think about bringing in those last two carbons, what you can see is that for every carbon, two of its hybrid orbitals are being used to bond to other carbons.
如果我们考虑引入最后两个碳原子,你会看到的是对于每个碳原子,其中的两个杂化轨道,和另外的碳原子成键。
So let's take the case of acetylene where we have two carbon atoms that are going to be triple bonded to each other, each are bonded to a carbon and then to one hydrogen.
让我们来看一看乙炔的例子,我们有两个碳原子,成三键,每个碳和一个碳一个氢相连。
So we can actually constructively and destructively combine these waves, these atomic orbitals to make a hybrid.
我们可以相长,和相消叠加这些波,这些原子轨道可以杂化。
So let's compare what some of the similarities and differences are between hydrogen atom orbitals, which we spent a lot of time studying, and now these one electron orbital approximations for these multi-electron atoms.
很长时间的氢原子轨道和,现在多电子原子中,的单个电子轨道近似,我们可以对比,它们之间,的相似性和不同。
Now, it's not going to be symmetric is it, because there's two fluorines and two chlorines.
现在,它将不会对称,因为有两个氟原子和两个氯原子。
And, as I mentioned, we left off and as we started back here to describe the atom and how the atom holds together the nucleus and the electron using classical mechanics.
我之前提及过,我们上次,讲到应用经典力学如何描述,一个原子以及原子如何把质子,和电子束缚在一起,今天我们要。
And there again is another difference between multi-electron atom and the hydrogen atoms.
在多电子原子和氢原子,之间还有一个区别,当我们谈论多电子原子轨道时。
I mean, the atom has a tiny mass, too, but what we are saying is compared to the totaled atomic mass, the mass of the electron is tiny.
我的意思是,原子的质量也很小,但是我们说的是,和整个原子质量相比,电子的质量是很小的。
If we think of the size of a typical atom, we would say that would be about 10 to the negative 10 meters. So, we can see the diameter of a nucleus is absolutely smaller really concentrating that mass into a very small space.
一个普通细胞的大小,抱歉,我和细胞核搞混了0,如果我们考虑,一个普通原子的大小,这大概是10的负十次方米,所以原子核的直径确实非常小,真的是把质量。
And they had this feeling because there had just been this huge boon of discovery, of scientific advances that included Newtonian mechanics, it included Dalton's atomic theory of matter, also thermodynamics and classical electromagnetism.
他们会有这样的感觉,是因为他们刚,经历科学上的,大繁荣期,包括牛顿力学,道尔顿物质原子理论,热力学和电磁学,都取得了巨大进展。
Since then, since we know about atoms and molecules now, we can rationalize the concepts of thermodynamics using microscopic properties, 62 and if you are going to take 5.62, that's what you'd learn about.
既然我们现在已经知道了原子和分子,的概念),我们可以用,微观属性,来阐释热力学中的概念,如果你会选修5。,-那是你将要学到的。
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