The structural moment of concentration on the code for its own sake cannot be avoided, and literature necessarily breeds its own formalism.
集中在代码上的结构瞬间,因为它本身的原因不可避免,文学必要地导致了它自身的形式主义。
So we'll talk specifically about drawing Lewis structures and then about formal charge and resonance, which are within Lewis structures.
因此我们会专门讲一讲,如何来画路易斯结构,然后再讨论形式电荷与共振论,它们也属于路易斯结构的范畴。
Now we have uncovered something about the form, the structure, of Tony the Tow Truck in saying this, but we haven't discovered or uncovered a thing about the meaning of Tony the Tow Truck.
我们现在已经讨论了一些关于,托尼的拖车,的形式和结构,但是还没有讲到,它的含义理解。
Now in Kaufman's view the similarities, therefore, between the Israelites and Ancient Near Eastern religion and cultures that everyone was so busily finding and celebrating, these were in the end similarities in form and external structure, appearance. They weren't essential similarities.
在考夫曼看来,人们苦苦寻找的,犹太与古近东宗教文化的相似点,只是在形式和外部结构上相同罢了,这些并不是必要的。
So we move now from the matter of the regime as to what constitutes its citizens and its citizen body to the question of the form of the regime its forms its formalities its structures and institutions you might say.
我们因此从政体的物质,即组构公民与公民本体的物质,转向政体形式的问题,其形式其形态,其结构与制度。
So now that we have enough practice drawing Lewis structures let's talk about actually figuring out this formal charge.
那么现在我们已经做了足够多的画路易斯结构的练习,让我们来讨论一下如何得出形式电荷。
And the last thing we do for any of our structures to check them and figure out are these valid or not valid, are these good Lewis structures is to check the formal charge.
而为了检验任何一个结构是否有效,看它们是不是好的路易斯结构,我们要做的最后一件事就是检查形式电荷。
So if we went through and drew out our Lewis structure following each of our steps, what we would get is this as our Lewis structure here, and we could figure out all of the formal charges.
那么如果我们按照流程,经过所有的步骤来画路易斯结构,我们会得到这样的路易斯结构,然后我们可以算出所有的形式电荷。
All right. So let's try one more example of drawing Lewis structures before we talk about formal charge.
好,让我们在讲形式电荷之前,再给一个例子画一下路易斯结构。
All right. So formal charge can actually help us out when we're trying to decide between several Lewis structures that look like they might be comparable in terms of which might be the lower energy or the more stable structure.
好的,形式电荷真的可以,帮助我们决定,在几种路易斯结构中,哪个更可能符合能量更低,或者结构更稳定的要求。
But I want you to tell me in terms of thinking about formal charge, which Lewis structure would you predict to be the most stable?
但我想让大家告诉我,从形式电荷的角度考虑,你会预测哪一个路易斯结构是最稳定的?
So, these are the different ways that we can actually go ahead and use formal charge when we're choosing between different types of Lewis structures.
那么,这些就是在我们需要在,不同的路易斯结构之间做选择的时候,我们如何用形式电荷来进行判断的各种方法。
But what I'm going to tell you already is this is a case where, in fact, it's an exception to the idea that the lowest energy structure has the lowest ionization energy in the middle, and we can figure this out when we look at formal charge.
但是我已经告诉大家这个例子,实际上,是中心原子电离能最低的结构,的能量最低这一思路的一个例外,我们可以通过形式电荷看出这一点。
So this means we can actually calculate this for any molecule that we've drawn the Lewis structure for, because we actually do need to draw the Lewis structure before we know, for example, how many of each of these we have, or at least go through the rules.
这意味着我们可以将原来画过,路易斯结构的分子的形式电荷计算出来,因为我们其实在画出,路易斯结构之后才能知道,比如,这些量的值是多少,或者至少我们需要经过前面的那些步骤。
So, we can also get into a case where we have similar values in terms of absolute values of formal charge between two different molecules we're deciding between in their Lewis structures.
我们还可能遇到另外一种情况,那就是在我们需要进行,选择的两种路易斯结构中,形式电荷具有相似的绝对值。
If we look at our last structure here where we have nitrogen the middle, we can also figure out all those formal charges, and in this case we have plus 1 on the nitrogen, we have minus 2 on the carbon, and then we end up with a 0 on the sulfur there.
如果我们来看看最后一个结构,在中间的原子是氮,我们同样可以计算出所有的形式电荷,而在这种情况下,氮为正一,碳为负二,而最后硫为零。
But we could, for example, look at a case where we have several different structures that look pretty good, and the one we want to determine as being the lowest energy structure is the one in which the absolute values of the formal charges are going to be lower, so essentially that they have less charge separation.
但是我们可能,比如,遇到一种情况,有好几个候选的路易斯结构看起来都挺好的,这时候我们就需要,通过比较哪个形式电荷的绝对值更低,来决定哪个结构的能量更低,本质上这个结构中分开的电荷更少。
So in our first structure, we would find for the nitrogen we have a formal charge 5 minus 4 minus 2, because we're starting with 5 valence electrons, so that is a formal charge of minus 1.
那么在我们的第一个结构中,我们发现氮的形式电荷量是五减去四4,再减去二,因为我们开始有五个价电子,因此它的形式电荷量是负一。
It's always a good first approximation, because you need to start somewhere in terms of drawing Lewis structures, but then if you go and figure out the formal charge and you just have lots of charge separation or very high charges, like a plus 2 and a minus 2 and a minus 1 all different places in the atom, what it should tell you is maybe there's a better structure.
它总是一个好的第一近似,因为在画路易斯结构的时候,你总需要一个起点,但是如果你在算出形式电荷之后,发现有很多电荷分开了,或者说有很高的电荷,比如有一个正二,一个负二,还有一个负一1,在原子的各个地方,这应该就是在告诉你,或许还有一个更好的路易斯结构。
Often a good thing to start with is to put the lowest ionization energy atom in the middle, and if you don't have charge separation then go with that structure, but if you do find you have a lot of separation, such as the case in negative 2, positive 2, and minus 1, then you want to say wait a second, this is really bad in terms of formal charge, let me go ahead and see what other options I have here.
通常一开始把电离能最低的原子,放在中心位置就很好了,如果你发现电荷没有分开,那么这个结构就没问题了,但是如果你发现有很多分开的电荷,比如这种情况,有负二,正二和负一,那么你会想要说等一下,从形式电荷来看这很不好,让我去看看其它可能的选择。
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