We can graph out what this is where we're graphing the radial probability density as a function of the radius.
我们可以,画出它来,这是径向概率密度,作为半径的一个函数图。
It's one of the only compounds, there's only I think three, where the density actually goes down when it freezes.
它是我见过的,唯一一个,在降温时密度下降的化合物。
Sometimes we have a very electronegative atom that's going to take more of its equal share of electron density.
有时候我们会有一个电负性很高的原子,它将会获取更多的共用电子密度。
You make the volume infinitely large, the density of the gas infinitely small.
密度无限小,气体分子之间的相互作用。
We have instead what's called a probability density when we have continuous random variables.
所以我们用概率密度的概念来描述,连续型随机变量的情况
How is anyone going to give you a density of anything?
你怎样获得任意物体的密度
Okay, the higher caloric density.
没错,高热量密度
We can talk about the wave function squared, the probability density, or we can talk about the radial probability distribution.
我们可以讨论它,波函数的平方,概率密度,或者可以考虑它的径向概率分布。
And when we define that as r being equal to zero, essentially we're multiplying the probability density by zero.
当我们定义r等于0处,事实上是把概率密度乘以0.
So for example, that might have a formal charge of negative 1, because to some extent it has gained that much electron density that it now has a formal charge that's negative.
比如,可能它的形式电荷为负一,因为在一定程度上它得到了这么多的共用电子密度,那么它现在就有了负的形式电荷。
Think of anything else with the density goes down when it freezes, and think about where we would be if that wasn't the case.
想想有没有其他的物质,在降温时密度会变大,再想想如果不是这种情况,我们将会怎么样。
And then he says the tetrachloride will be volatile, 9 and it will have a density of 1.9.
他说四氯化物具有不稳定性,密度是1。
And he predicts the density of the oxide of the yet undiscovered element.
他预测这个还未被发现的元素的,氧化物的密度。
Ah, but density is mass over volume.
但密度是质量除以体积
So, one way we could look at it is by looking at this density dot diagram, where the density of the dots correlates to the probability density.
其中一个理解它的方法,就是通过看这个密度点图,这里点的密度,和概率密度想关联的。
So you can think about how these 2 things combined are going to be electronegativity, which is a measure of how much an atom wants to pull electron density away from another atom.
因此你可以想象出,这两样性质合起来就是电负性,也就是一个度量,关于一个原子,有多希望把另一个原子的电子密度拉过来的。
So again if we look at this in terms of its physical interpretation or probability density, what we need to do is square the wave function.
如果我们从物理意义或者,概率密度的角度来看这个问题,我们需要把波函数平方。
But a real key in looking at these plots is where we, in fact, did go through zero and have this zero probability density.
是我们经历这些零值,而且有这些零概率密度,我们把它叫做节点。
So it's just a measure of how much does one given atom want to pull away electron density from, let's say, an adjacent atom.
因此,它就是度量一个给定原子有多么,想把电子密度拉过来,可以说,从相邻的一个原子那里。
So if I try to rotate my 2 atoms, you see that I have to break that pi bond, because they need to be lined up so that the electron density can overlap.
如果我要试着转动两个原子,你会看到我必须要打破一个π键,因为他们需要连接起来,让那些电子能够重叠。
This is not a node because a node is where we actually have no probability density.
因为节点处是,没有概率密度的,所以。
So again, we can think about the probability density in terms of squaring the wave function.
同样的,我们可以把,波函数平方考虑概率密度。
So, what we're going to define is just let's just capture 90% of that electron density.
所以,我们所定义的,只包括百分之九十的电子密度。
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