// 你或许知道所有东西都是由原子组成的
You probably know that all stuff is made up of atoms
// 而原子本身
and that an atom
// 是一个非常非常非常小的粒子
is a really, really, really, really tiny particle.
// 每个原子都有一个核
Every atom has a core,
// 由至少一个带正电的粒子组成
which is made up of at least one
// 这个正电粒子叫做质子
positively charged particle called a proton,
// 大多数情况下
and in most cases
// 还有一些中性粒子叫做中子
some number of neutral particles called neutrons
// 原子核被成为电子的负电粒子包围
That core is surrounded by negatively charged particles called electrons
// 一个原子的特性仅由原子核中质子的数量来确定
The identity of an atom is detemined only by the number of protons in ints nucleus
//氢就是氢，因为它只有一个质子
Hydrogen is hydrogen because it has just one proton
// 碳之所以是碳是因为它有6个质子
carbon is carbon because it has six
// 金之所以是金是因为它有79个质子
gold is gold because it has 79
// 诸如此类的还有很多
and so on
// 请允许我讲会儿题外话
Indulge me in a momentary tangent
// 我们是如何知道原子的结构的呢？
How do we know about atomic structure?
// 我们又看不见质子、中子、或电子
We can’t see protons, neutrons, or electrons
// 所以，我们做了一堆实验
So, we do a bunch of experiments
// 然后构造一个我们认为是对的模型
and develop a model for what we think is there
// 然后我们做更多的实验
Then we do some more experiments
// 来看看实际情况是否符合模型
and see if they agree with the model
// 如果是，那最好了
If they do, great
// 如果不是，那就是时候来建一个新模型了
If they don’t, it might be time for a new model
//自公元前400的德谟克利特以来，我们有很多不同的原子模型
We’ve had lots of very different models for atoms since Democritus in 400 BC
// 而且将来肯定会有更多的模型出现
and there will almost certainly be many more to come
// 好了，题外话结束
Okay, tangent over
// 原子的核心往往是粘在一起的
The cores of atoms tend to stick together
// 但电子可以自由移动
but electrons are free to move
// 这就是化学家爱电子的原因了
and this is why chemists love electrons
// 如果我们可以和它们结婚，我想我们会的
If we could marry them, we probably would
// 但是电子很奇怪
But electrons are weird
// 它们的表现即像是粒子，像是小棒球
They appear to behave either as particles, like little baseballs
// 也像是波浪，水的波浪
or as waves, like water waves
// 它们在不同的实验中有着不同的表现
depending on the experiment that we perform
// 关于电子最奇怪的事情是我们无法知道它们的确切位置
One of the weirdest things about electrons is that we can’t exactly say where they are
// 并不是说我们没有合适的设备，这种不确定性也是我们的电子模型的一部分
It’t not that we don’t have the equipment, it’s that this uncertainty is part of our model of the electron
// 所以，好吧，我们不能精确定位它们
So，we can’t pinpoint them, fine
// 但我们可以说，在原子核周围的一个给定区域，找到一个电子的几率是多少
But we can say there’s a certain probability of finding an electron in a given space around the nucleus
// 这就意味着我们可以问以下的问题
And that means that we can ask the following question
// 如果我们绕原子核画一个形状
If we drew a shape around the nucleus
// 使得我们将95%的把握在这个形状中找到一个给定的电子
such that we would be 95% sure of finding a given electron within that shape
// 它会是什么样的？
what would it look like?
// 这里有几个形状
Here are a few of these shapes
// 化学家们称之为轨道
Chemists call them orbitals
// 决定每个轨道的形状的因素之一，是它们拥有能力的多少
and what each one looks like depends on, among other things，how much energy it has
// 一个轨道拥有的能量越多
The more energy an orbital has
// 那么它的主要部分就离原子核越远
the farther most of its density is from the nucleus
// 为什么我们选择95%的把握而不是100%
By the way, why did we pick 95% and not 100%?
// 好吧，那时我们电子模型另一个比较特殊的地方。
Well, that’s another quirk of our model of electron
// 从离开原子核的一定距离开始
Past a certain distance from the nucleus
// 发现电子的几率开始随着距离下降
the probability of finding an electron starts to decrease
// 差不多呈指数衰减
more or less exponentially
// 这就意味着几率会越来越接近零
which means that while it will approach zero
// 但事实上永远不会达到零
it’ll never actually hit zero
// 所以在每个原子中，总有一些很小，但非零的可能性，在很短很短的一段时间里
so in every atom, there is some small, but non-zero, probability that for a very, very, short period of time
// 其中一个电子正位于宇宙的另一端
one of its electrons is at the other end of the known universe
// 但是大部分时间电子都距离原子核很近
But mostly electrons stay close to their nucleus
// 呈现为带负电的电子云会随着时间改变位置
as clouds of negative charged density that shift and move with time
// 一个原子的电子如何和另一个原子的电子互相作用几乎决定了一切
How electrons from one atom interact with electrons from another determines almost everything
// 原子可以放弃的电子把它们给其他原子
Atoms can give up their electrons surrendering them to other atoms
// 或者与其他原子共享电子
or they can share electrons
// 而这个社交网络的动态
And the dynamics of this social network
// 使化学变得有趣
are what make chemistry interesting
// 从普通的旧石头
From plain old rocks
// 到美好而复杂的生命
to the beautiful complexity of life
// 自然界中一切我们可以看到的，听到的，闻到的，尝到的，触摸到的，甚至感觉到的，都是在原子层面决定的
the nature of everything we see, hear, smell, taste , touch , and even feel is determined at the atomic level