And you see where the most electronegative elements are, and fluorine is the most electronegative of the active elements.
你找一下电子力最大的元素在哪,氟是活泼元素中,电子力最大的。
And, likewise, if we look at fluorine in its diatomic molecule, it is 160 kilojoules per mole.
一样的,如果我们观察二价的氟,它是每摩尔160焦。
So, she is interested in how this molecule, gemcitabine, inhibits an enzyme. So, to do those studies, she needs to know a lot of the stuff on this list.
她对这个分子,二氟脱氧胞嘧啶核苷怎么抑制酶很感兴趣,要做这些研究。
In terms of where different atoms are in a molecule, if you have a hydrogen atom or a fluorine atom, you can pretty much guarantee they're always going to be terminal atoms.
对于不同原子在分子中的位置,如果你有一个氢原子或者一个氟原子,那你基本可以保证,它们总是最末端的原子。
- And we can think about why -- essentially we have fluorine and now we're adding another electron. So you can picture that fluorine is going to get larger in this case And that would be true for all of the negatively charged ions.
我们可以想一想这是为什么-,本质上来讲我们现在给氟原子加上了,另外一个电子,因此大家可以想象在这种情况下氟将变大,而且这对于其它负离子也是成立的。
Whereas for fluorine, fluorine is smaller than f minus is the one that's the outer shell shown here.
而对于氟来说,氟原子更小,与外部壳层在这的负一价氟离子相比。
And, this one here, some of you might recognize, is dichlorodifluoromethane. It's also known as a CFC.
而且在这些当中有些你或许认识,是二氯二氟化碳,它也是众所周知的氟利昂。
Now here is fluorine, same skeleton, only fluorine has seven valence electrons.
这是氟,同样的结构,只有氟有七个价电子。
So if we want to write out what that would be, it would just be to say that f minus is isoelectronic with neon.
那么如果我们把它写出来,它应该就是负一价的氟离子与氖原子是等电子的。
So let's do a quick clicker question, and you tell me how many valence electrons does fluorine have? Remember, valence electrons are different from core, they're only the outer-most electrons in the outer-most shell.
那么让我们来做一个小选择题,请大家来告诉我,氟有多少个价电子,要记得,价电子与芯电子不同,它们是在最外壳层的最靠外面的电子。
As we see a little bit later, I could talk about the carbon-hydrogen bond in methane where there is a plurality of bonds. In this case, there is only the one bond but I just want to get the formulas.
因为我们后来看到一点点,我能讨论甲烷中的碳氢共价键,那有许多共价键,这种情况下,这只有一条共价键,但我想得到氟。
Now, if I get over here, HF, I know that fluorine is hogging the electron, so it is not equal sharing. It is over here.
那我们再看到这里,氟化氢,我知道氟在拉电子,所以它就不是平均共价。
All right. So it's 7 that are in chlorine, it's the same as fluorine or any of the others in that row or in that group rather.
好,氯有七个,跟氟或者在那一列,的其它元素一样。
So for example, if we think about fluorine, 1 s 2 2 s 2 2 p 5 that has an electron configuration of 1 s 2, 2 s 2, 2 p 5, so all we would need to do is add one more electron to get the same configuration as for neon.
比如,如果我们考虑氟原子的话,它的电子排布是,因此我们所需要做的就是给它加上一个电子,使得它与氖原子的电子排布相同。
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。
So, we see is when we use the octet rule to look at fluorine molecule, we're combining two fluorine atoms, and what we end up with is an f f molecule where they're sharing two electrons, so making that covalent bond.
那么,我们看到把八隅体规则用到氟分子上,就是把两个氟原子组合起来,最终得到的氟分子中两个原子,共用一对电子,这就构成了共价键。
But that each individual fluorine atom has eight electrons, or full octet around it.
但是每个氟原子现在都有八个电子,或者说周围有一个填满的八隅体。
So, we can say that -- if we have neon here and we want to think about what's isoelectronic, -- f minus would be isoelectronic. We also have oxygen -- what would the charge on oxygen be? Um-hmm, right. 2 minus.
那么,我们可以说--如果我们这里有氖原子,而我们想知道与它等电子的是什么,负一价的氟离子就是与它等电子的,我们还有氧-,氧应该是几价的?没错,负二价。
So I said that we want to be talking about valence electrons here, so that means if we're talking about, for example, the octet rule for an f f molecule where we have two fluorine atoms, we need to write the valence electrons as dots around them.
我说过我们在这要讨论的是价电子,这就意味着,如果我们要讨论,比如,关于两个氟原子组成的分子的八隅体规则,我们首先需要把价电子画成围绕在它们周围的点。
That is nonpolar. And likewise for fluorine, F2.
他就是非极性的,同样,氟气也是的。
And so this is the H-F bond in HF.
所以这是氟化氢中的氢氟共价键。
Here is oxygen and fluorine.
这就是氧和氟。
So, for example, if we think of the fluorine minus case, would you expect fluorine minus to be larger or smaller than neutral fluorine? Okay. I heard mostly larger, but a little bit of a mix in there, and it turns out that larger is correct.
比如,如果我们来考虑一下负一价的氟离子的话,大家认为它大一些还是小一些?,对比于比中性氟原子,好的,我听到大部分人说大一些,但是也有一些不同意见,而正确答案应该是大一些。
And here the electrons are actually donated, so this becomes F minus.
非平均共价,到这里,电子被完全提供给F,这是氟负离子。
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