Reactants become products and that's that.

反应变成，仅此而已。

But how does the leaf prevent unwanted intruders, like bacteria from getting in and stop important reactants from escaping?

但是，叶子要如何防止不必要的入侵者（如细菌）进入并阻止重要的反应逸出？

Below that is the spongy mesophyll, which have plenty of space in between them for reactants to move through.

下面是海绵状中叶，它们之有够的空供反应移动通过。

So over here on the left-hand side we have the reactants.

所以在左侧里我们有反应。

So here we have the reactants.

所以里有反应。

The products are also breaking back apart into the reactants.

也分解成反应。

And so what are the reactants here?

那么里的反应是什么？

If I raise the temperature, it's like adding a reactant so the reaction will proceed to the right.

如果我提高温度， 就好像添加了一种反应， 样反应就会向右进行。

If you actually provide more reactants, you're gonna go more in that direction.

如果你真的提供了更多的反应，你就会朝着那个方向走得更多。

That was one of our reactants and it dissolves readily in water, hence the oceans.

那是我们的反应之一， 它很容易溶解在水中， 因此很容易溶解在海洋中。

More ammonia molecules are available to break up into the reactant gases.

更多的氨分子可用于分解成反应气体。

One particular ratio of reactants to products where the products form at the same rate that they break down.

一种特定的反应与的比例， 其中的形成速率与它们分解的速率相同。

But sometimes, there's an opposite reaction that occurs with the products changing back into the reactants.

但有时，随着变回反应， 会发生相反的反应。

So again, it's the product of the products of the product of the reactants and the coefficients become exponents.

同样，它是反应乘积的乘积， 系数变成指数。

Then, plug in the number of moles for each of our products and reactants.

然后，为我们的每种品和反应插入摩尔数。

Reconciling the reactants with the products is called equation balancing, and it's a good bit of what stoichiometry is all about.

将反应与调和称为方程式平衡，很好地说明了化学计量学的全部内容。

The capital letters stand for the reactants and the products and the lowercase letters stand for their coefficients.

大写字母代表反应和，小写字母代表它们的系数。

That's why reactants like this are written with a double arrow, indicating that the process runs both directions.

就是为什么像样的反应用双箭头书写， 表明该过程是双向进行的。

A leaf is like a plant's food factory — and its parts work together to get the reactants into one place so that photosynthesis can happen.

叶子就像植的食品工厂——它的各个部分一起工作，把反应带到一个地方，样就可以进行光合作用。

But what if you don't know the standard free energies of formation for the products and reactants?

但是，如果您不知道和反应的标准生成自由能怎么办？