The uncertain location of electrons - George Zaidan and Charles Morton

电子位置的不确定性- 乔治·扎伊丹和查尔斯·莫顿

翻译人员: xuanyu shi 校对人员: Qingqing Mao

You probably know that all stuff is made up of atoms

你或许知道所有东西都是由原子组成的。

and that an atom

而原子本身

is a really, really, really, really tiny particle.

是一个非常非常非常小的粒子。

Every atom has a core,

每个原子都有一个核，

which is made up of at least one

由至少一个带正电的粒子组成，

positively charged particle

这个正电粒子叫做质子，

called a proton,

and in most cases,

大多数情况下，

some number of neutral particles called neutrons.

还有一些中性粒子叫中子。

That core is surrounded

原子核被称为电子的负电粒子包围。

by negatively charged particles called electrons.

The identity of an atom is determined

一个原子的特性

only by the number of protons in its nucleus.

仅由原子核中质子的数量来确定。

Hydrogen is hydrogen because it has just one proton,

氢就是氢，因为它只有一个质子，

carbon is carbon because it has six,

碳之所以是碳是因为它有6个质子，

gold is gold because it has 79,

金之所以是金是因为它有79个质子，

and so on.

诸如此类的还有很多。

Indulge me in a momentary tangent.

请允许我讲会儿题外话。

How do we know about atomic structure?

我们是如何知道原子的结构的呢？

We can't see protons, neutrons, or electrons.

我们又看不见质子、中子或电子。

So, we do a bunch of experiments

所以，我们做了一堆实验，

and develop a model for what we think is there.

然后构造一个我们认为是对的模型。

Then we do some more experiments

然后我们做更多的实验

and see if they agree with the model.

来看看实际情况是否符合模型。

If they do, great.

如果是，那最好了。

If they don't, it might be time for a new model.

如果不是， 那就是时候来建一个新模型了。

We've had lots of very different models for atoms

自公元前400年的德谟克利特以来，

since Democritus in 400 BC,

我们有很多不同的原子模型，

and there will almost certainly

而且将来肯定会有更多的模型出现。

be many more to come.

Okay, tangent over.

好了，题外话结束。

The cores of atoms tend to stick together,

原子的核心往往是粘在一起的，

but electrons are free to move,

但电子可以自由移动，

and this is why chemists love electrons.

这就是化学家爱电子的原因了。

If we could marry them,

如果我们可以和它们结婚，

we probably would.

我想我们会的。

But electrons are weird.

但是电子很奇怪。

They appear to behave either as particles,

它们的表现既像是粒子，

like little baseballs,

像是小棒球，

也像是波浪，水的波浪。

or as waves, like water waves,

depending on the experiment that we perform.

它们在不同的实验中有着不同的表现。

One of the weirdest things about electrons

关于电子最奇怪的事情是

is that we can't exactly say where they are.

我们无法知道它们的确切位置。

It's not that we don't have the equipment,

这并不是说我们没有合适的设备，

it's that this uncertainty

而是这种不确定性

is part of our model of the electron.

也是我们的电子模型的一部分。

So, we can't pinpoint them, fine.

所以，好吧，我们不能精确定位它们。

But we can say there's a certain probability

但我们可以说，

of finding an electron in a given space

在原子核周围的一个给定区域中

around the nucleus.

找到一个电子的几率是多少。

And that means that we can ask the following question:

这就意味着我们可以问以下的问题：

If we drew a shape around the nucleus

如果我们绕原子核画一个形状，

such that we would be 95% sure

使得我们将有95％的把握

of finding a given electron within that shape,

在这个形状中找到一个给定的电子，

what would it look like?

它会是什么样的？

Here are a few of these shapes.

这里有几个形状，

Chemists call them orbitals,

化学家们称之为轨道。

and what each one looks like

决定每个轨道的形状的因素之一

depends on, among other things,

how much energy it has.

是它们所拥有能量的多少。

The more energy an orbital has,

一个轨道拥有的能量越多，

the farther most of its density is

那么它的主要部分就离原子核越远。

from the nucleus.

By they way, why did we pick 95%

顺便提一下，

为什么我们选择95%的把握而不是100%？

and not 100%?

Well, that's another quirk

好吧，那是我们电子模型另一个比较特殊的地方。

of our model of the electron.

从离开原子核的一定距离开始，

Past a certain distance from the nucleus,

the probability of finding an electron

发现电子的几率

starts to decrease

开始随着距离下降，

more or less exponentially,

差不多呈现指数衰减，

which means that while it will approach zero,

这就意味着几率会越来越接近零，

it'll never actually hit zero.

但事实上永远不会达到零。

So, in every atom,

所以，每一个原子中，

there is some small, but non-zero, probability

总有一些很小，但是非零的可能性，

that for a very, very short period of time,

在很短很短的一段时间里

one of its electrons

其中一个电子

is at the other end of the known universe.

正位于宇宙的另一端。

But mostly electrons stay close to their nucleus

但是大部分时间电子都距离原子核很近，

as clouds of negative charged density

呈现为带负电的电子云，

that shift and move with time.

电子云会随着时间改变位置。

How electrons from one atom

一个原子的电子如何和

interact with electrons from another

另一个原子的电子互相作用

determines almost everything.

几乎决定了一切。

Atoms can give up their electrons,

原子可以放弃自己的电子，

surrendering them to other atoms,

把它们给其他原子，

or they can share electrons.

或者与其他原子共享电子。

And the dynamics of this social network

而这个社交网络的动态

are what make chemistry interesting.

使化学变得有趣。

From plain old rocks

从普通的旧石头

to the beautiful complexity of life,

到美好而复杂的生命，

the nature of everything we see,

自然界中一切我们可以看到的，

hear,

听到的，闻到的

smell, taste, touch, and even feel

品尝到的，

触摸到的，

is determined at the atomic level.

都是在原子层面决定的。