The sodium, this became a cation, because it's positive.

钠，这变成了子，因为它是。

Cations are positively charged and anions are negatively charged.

子带电， 子带负电。

So cations only react with anions to form new compounds.

所以子只与子反应形成新化合物。

Silver is also a metal and is also a cation.

银也是一金属， 也是一子。

But they're really just positively-charged cations — like calcium, sodium, and potassium — and negatively-charged anions, like phosphate, sulfate, and bicarbonate.

但它们实际上只是带电子——比如钙、钠和钾——和带负电子，比如磷酸盐、硫酸盐和碳酸氢盐。

And don't just think that there's one anion and one cation.

不要只是认为只有一子和一子。

But how do we know which ions are cations and which are anions?

但是我们怎么知道哪些子是子哪些是子呢？

Alkali metals want nothing more than to dump off an electron and form a positive ion, or cation.

碱金属只想释放电子并形成子或子。

Now, when we name ionic compounds, we just say the cation first, and the anion second.

现在，当我们命名子化合物时， 我们只是先说子， 然后再说子。

But the names of these ions change somewhat depending on whether they are cations or anions.

但是这些子名称会根据它们是子还是子而有所不同。

They all form ions readily when they react with non-metals, and when they do, they always lose electrons, forming cations.

当它们与非金属反应时， 它们都很容易形成子，当它们发生反应时， 它们总是失去电子， 形成子。

Iron, for example, in the middle there, forms cations, but they can have a charge of either two or three.

例如，铁在中间形成子， 但它们可以带两个或三个电。

Ions that have lost electrons, and therefore take on a positive charge, are cations. Whereas ones that gain electrons to become negative are anions.

失去电子并因此带电子是子。而那些获得电子变成负子是子。

Next, you have the alkaline earth metals - reactive metals, but not as reactive as the alkali metals, forming cations with two positive charges instead of just one.

接下来，你有碱土金属 - 活泼金属， 但不像碱金属那样活泼，形成带有两个电而不是一个电子。

There is a slight complicating factor in that modern Chinese texts produced for business purposes, such as contracts, patents or specifi cations, were, in the early years of China's liberalisation, sometimes adapted from English texts.

在一定程度上， 现代中文商业文本，如合同、专利或规范，在中国早期改革开放时期有时是从英文文本改编而来。

The pay was not great, the position was at the bottom, the hours were long, and the work consisted of the rather mundane task of looking over patent appli- cations, but Einstein leaped at the chance.

薪酬并不高， 职位处于底层，工作时间长， 内容也不过是审查专利申请这相当平凡任务，但爱因斯坦却毫不犹豫地抓住了这个机会。