What is needed for photosynthesis to take place? Sophie.

光合作用的反应是什么？苏菲。

Reactants become products and that's that.

反应变成产，仅此而已。

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，它们之有足够的反应移动通过。

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

但是，叶子如何防止不必的入侵者（如细菌）进入并阻止重的反应逸出？

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

所以在左边我们有反应。

We can do that by either measuring the reactants or the products.

我们可以通过测量反应或生成来实现这一点。

But what was it about the reagent that revealed the ink?

是什么反应揭示了墨水？

And gravimetric analysis what we're doing is we're taking two reactants and we're combining those.

我们进行的重量分析是取两种反应并将它们混合在一起。

So here we have the reactants.

所以这里我们有反应。

And so what are the reactants here?

这里的反应是什么？

So it's going to convert certain reactants into products.

因此，它将把某些反应转为产。

And so this reaction, one of the reactants are going to be 6 molecules of water.

在这个反应中，反应之一将是 6 个水分子。

How much of that original product or reactant did we have.

我们有多少原始产或反应。

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生成，小写字母代表它们的系数。

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

但有时，随着产变回反应， 会发生相反的反应。

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

如果你实际上提了更多的反应，反应就会朝着那个方向进行更多。

Chemists often know not only the equilibrium constant for a reaction, but also how much of each reactant is available.

家不仅知道一个反应的平衡常数，还知道每种反应有多少可用。

We could measure the products that are created or we could measure the amount of reactants that are being consumed.

我们可以测量生成的产，或者测量正在被消耗的反应的量。

And the importance of K, which is a measure of the concentration of products to reactants.

K 的重性在于它是产与反应的浓度的量度。

Now we can get rid of that reactant since it's a solid.

现在我们可以除去该反应，因为它是固体。