of compounds.

As引导原因状语从句

to manipulate the structure of compounds不定式短语做宾补 随着化学家对化学键认识的发展，他们获得了控制化合物结构的能力。

Dynamite, birth control pills, synthetic fibers, and a thousand other products were fashioned in chemical laboratories and () have dramatically changed the way we live.

炸药、避孕药、合成纤维，和数以千计的其他产品在实验室中被合成出来，并且魔术般的改变了我们的生活。

We are now entering an era that promises (some would say forebodes) even greater change.

我们现在进入了一个可望（或者说预言）更大变化的时代。

The DNA molecular—— the chemical basis of heredity —— carries its genetic message in its bonds in DNA.

分子DNA——遗传物质的基础——以它的键传递遗传信息。 Whether an organism is fish, fowl, hippopotamus, or human is determined by the arrangement of bonds in DNA.

Whether an organism is fish, fowl, hippopotamus, or human做主语

无论一个生物体是鱼、家禽、河马还是人，都是由于DNA的

键的组合方式决定的。

Scientists already have the ability to rearrange these bonds, and this ability has given them limited control over the structure of living matter.

Them, limited control over the structure of living matter双宾语 科学家已经获得了重组这些键的能力，而这种能力给了他们有限的对生物体结构的控制。

As techniques of genetic engineering improve, scientists may literally be able to custom-tailor genes.

随着基因工程的发展，科学家们将最终设计出符合条件的基因。

Let us begin our consideration of chemical bonding so that we, too, can understand the forces that control the structure of matter, living and nonliving.

That引导定语从句修饰forces，

living and nonliving，动名词，matter得同位语，修饰matter 让我们开始对化学键的论述，并由此理解控制物质，包括有生命体和无生命体，的结构的力。 Ionic Bond 离子键

Let us look at an atom of the element sodium (Na). 我们看一下钠原子。

It has 11 electrons, of which two are in the first energy level,

eight in the second, and one in the third. the first energy level第一能级 the second energy level第二能级 the third energy level第三能级

It has 11 electrons, of which two are in the first energy level, eight are in the second energy level, and one is in the third energy level.

它有11个电子，其中2个电子在第一能级，8个电子在第二能级，1个电子在第三能级。

If the sodium atom could get rid of an electron, then the product, called a sodium ion, would have the same electron structure as an atom of the noble gas neon (Ne).

called a sodium ion 分词短语做非限定，修饰product noble gas

如果钠原子能够失去1个电子，产物称为钠离子，就和惰性气体氖（Ne）具有相同的电子结构。

Let us immediately emphasize that the sodium ion (Na+) and neon atom (Ne) are not identical.

让我们首先强调一下，钠离子（Na＋）和氖原子（Ne）并不相同。

The electron arrangement is the same, but the nuclei—— and resulting charges—— are not.

electron arrangement 电子排布 resulting charges最终电荷

电子排布是相同的，而核及最终电荷是不同的。

As long as sodium keeps its 11 protons, it is still a form of sodium, but it is the sodium ion, not the sodium atom.

只要钠带有11个质子，它就一直是钠，但它是钠离子而不是钠原子。

Ions are charged particles, particles in which the number of electrons does not equal the number of protons. in which 引导非限定定语从句。

离子是一种带电粒子，一种电子数不等于质子数的粒子。 Positively charged ions are called cations (pronounced “cat-ions”). The sodium ion is a cation.

带正电荷的粒子称为阳离子（音为阳－离子）。钠离子是阳离子。

If a chlorine atom (Cl) could gain an electron, it would have the same electron structure as the noble gas argon (Ar).

如果氯原子（Cl）能够得到一个电子，它将与惰性气体氩（Ar）具有相同的电子结构。

The chlorine atom, having gained an electron, becomes negatively charged. It has 17 protons (17+) and 18 electrons (18-). It is written Cl- and it called a chloride ion.

having gained an electron动名词形式做定语，修饰chlorine atom

获得一个电子的氯原子带有负电荷。它具有17个质子（17+）和18个电子（18－），写作Cl，称为氯离子。

Negatively charged ions are called anions (pronounced “ann-ions”). The chloride ion is an anion.

带负电荷的粒子称为阴离子（音为阴－离子）。钠离子是阴离子。

A sodium forms a less reactive species, a sodium ion, by losing an electron.

a less reactive species, a sodium ion同位语 钠原子通过失去一个电子形成不活泼的钠离子。

A chlorine atom becomes a less reactive chloride ion by gaining an electron.

氯原子通过得到一个电子形成不活泼的氯原子。

A chlorine atom cannot just pluck an electron from empty space, nor can a sodium atom kick out an electron unless something else is willing to take it on.

empty space 空白空间、真空空间，意为“凭空”、“无根据” nor作连词，与助动词和情态动词连用，句中主语与动词倒置。 He can’t see, nor could he hear until a month ago. 他现在看不

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