If they've got a double bond, we call them alkenes, and those with triple bonds are alkynes.

如果它们含有双键，我们称它们为，而含有三键的则称为。

All the other naming rules apply to alkenes and alkynes too.

所有其他的命名规则也适和。

Thus, no isomers with alkynes. Phew. OK I'm done describing for the moment.

因此，没有异构体。松了口气。好吧，我暂时先描述到这。

There's only one letter changing here: A in alkanes changes to E for alkenes and then to Y for alkynes.

这里只有一个字母在变化：烷的A变成了的E，然后再变成的Y。

They can be alkanes or alkenes, sometimes, even rarely, alkynes.

它们可以是烷或，有时甚至是罕见的。

The triple bonds in alkynes, meanwhile, are composed of 1 sigma bond and 2 pi bonds for a total of 3 bonds.

的三键由1个σ键和2个π键组成，总共3个键。

Alkenes can be made into alkanes and alkynes can become either alkenes or alkanes depending on how many atoms are added.

可以转化为烷，而则可以根据添加的原子数量变成或烷。

You also learned a little bit about cis-trans isomerism and learned a few important reactions of alkenes and alkynes such as hydrogenation, halogenation, and polymerization.

你还了解了一点关顺反异构体的知识，并学习了一些和的重要反应，如氢化、卤化和聚合。

So three words representing three different groups of organic compounds: alkanes for all single bonds, alkenes if they contain double bonds, and alkynes if they contain one or more triple bonds.

所以三个词代表三种不同的有机化合物组：烷表示全单键，表示含有双键，表示含有一个或多个三键。

That may not sound like a big deal at first, but alkenes and alkynes don't have that kind of freedom, and that simple fact has a huge affect on their properties.

这乍一听可能不算什么大不了的事，但和就没有这种自由度， 这个简单的事实对其性质产生了巨大影响。

If you paid attention, you learned that hydrocarbons with double bonds are called alkenes and those with triple bonds are called alkynes and that the naming rules are the same as for alkanes.

如果你注意听了，你应该知道带有双键的碳氢化合物称为， 带有三键的称为， 而且它们的命名规则与烷相同。