How atoms bond - George Zaidan and Charles Morton

原子如何鍵結 - 喬治子丹和查爾斯·莫頓

譯者: 陳 運昇 審譯者: 瑞文Eleven 林Lim

Most atoms don't ride solo,

大多數原子不獨自運作，

instead they bond with other atoms.

相反的，他們與其他原子結合。

And bonds can form between atoms

相同的元素

of the same element

或不相同的元素

or atoms of different elements.

之間可以形成鍵結。

You've probably imagined bonding as a tug of war.

你可能會把鍵結聯想成拔河。

If one atom is really strong,

如果一個原子真的很強，

it can pull one or more electrons

它可以由另一個原子

off another atom.

拉走一個或多個電子。

Then you end up with one negatively charged ion

然後，會產生一個 帶有負電荷的離子，

and one positively charged ion.

和一個帶正電荷的離子。

And the attraction between these opposite charges

這些相反電荷之間的吸引力

is called an ionic bond.

被稱作離子鍵。

This is the kind of sharing

這像是一種分享

where you just give away your toy to someone else

在這裡你只將玩具給別人

and then never get it back.

然後就再也沒有拿回來。

Table salt, sodium chloride,

食鹽就是氯化鈉，

is held together by ionic bonds.

由離子鍵結合在一起。

Every atom of sodium gives up one electron

每個鈉原子提供一個電子

to every atom of chlorine,

給氯的每一個原子，

ions are formed,

當離子形成時

and those ions arrange themselves

那些離子將會

in a 3D grid called a lattice,

在3D晶格中，

in which every sodium ion

每一個鈉離子

is bonded to six chloride ions,

都會跟六氯離子結合。

and every chloride ion is bonded

每個和氯離子也將會

to six sodium ions.

和六個鈉離子結合。

The chlorine atoms never give

氯原子絕不會放掉鈉的電子。

the sodium atoms their electrons back.

Now, these transactions aren't always so cut-and-dried.

現在，這些交易並非 總是如此俐落和完整。

If one atom doesn't completely overwhelm the other,

如果一個原子 無法完全壓倒對方，

they can actually share each other's electrons.

他們實際上可以 分享彼此的電子。

This is like a pot luck

這就好比每人出一菜的便飯，

where you and a friend each bring a dish

你和你的朋友 各自帶來一盤菜，

and then both of you share both dishes.

然後你們倆可以 同時共享美食。

Each atom is attracted to the shared electrons

在每一個原子之間，

in between them,

電子會被吸引成共用電子對，

and this attraction is called a covalent bond.

這種吸引力被稱為共價鍵。

The proteins and DNA in our bodies,

例如在我們身體中的 蛋白質與DNA，

for example,

are held together largely by these covalent bonds.

大部分由這些共價鍵 結合在一起。

Some atoms can covalently bond

有一些原子只與

with just one other atom,

一個原子共價結合，

others with many more.

有些可與多個原子結合。

The number of other atoms

一個原子能與

one atom can bond with

幾個原子結合，

depends on how its electrons are arranged.

取決於電子排列方式。

So, how are electrons arranged?

那麼，如何排列電子？

Every atom of a pure, unbonded element

單一、無鍵結的原子

is electrically neutral

是電中性。

because it contains the same number

因為它原子核內的質子數目

of protons in the nucleus

as it does electrons around the nucleus.

與核周圍的電子數目相同。

And not all of those electrons are available for bonding.

但不是所有的電子都可用於鍵結，

Only the outermost electrons,

只有最外層的電子，

the ones in orbitals furthest from the nucleus,

在軌道離原子核最遠，

the ones with the most energy,

這些能量最大者，

only those participate in bonding.

才會參與鍵結。

By the way, this applies to ionic bonding too.

順便說一下， 這也適用於離子結合。

Remember sodium chloride?

記得氯化鈉嗎？

Well, the electron that sodium loses

那麼，鈉失去的電子

is the one furthest from its nucleus,

是離原子核最遠的電子，

and the orbital that electron occupies

該電子被氯原子吸引後，

when it goes over to chlorine

也是占據氯原子

is also the one furthest from its nucleus.

最外圍的軌道。

But back to covalent bonding.

但是，回到共價鍵的結合。

Carbon has four electrons

碳有四個電子

that are free to bond,

即可以自由地結合，

nitrogen has three,

氮有三個、

oxygen two.

氧氣兩個。

So, carbon is likely to form four bonds,

所以，碳是可能形成四個鍵結，

nitrogen three,

氮有三個，

and oxygen two.

和氧氣兩個。

Hydrogen only has one electron,

氫只有一個電子，

so it can only form one bond.

所以它只能形成一個鍵結。

In some special cases,

在某些特殊情況下，

atoms can form more bonds

原子可形成比你所預期

than you'd expect,

還多的鍵結。

but they better have a really good reason to do so,

但他們最好有 充分的理由這樣做，

or things tend to fly apart.

要不然原子往往會飛散開來。

Groups of atoms

能與對方共享共價電子的原子團

that share electrons covalently with each other

被稱為分子。

are called molecules.

They can be small.

它們可以是很微小的。

For example, every molecule of oxygen gas

例如，氧氣中的每個分子

is made up of just two oxygen atoms

僅由兩個氧原子組成，

bonded to each other.

彼此結合。

Or they could be really, really big.

或者，他們可以是 非常、非常巨大。

Human chromosome 13 is just two molecules,

人類的第13號染色體 只有兩個分子，

but each one has over 37 billion atoms.

但每個都有超過37億個原子。

And this neighborhood,

而這附近，

this city of atoms,

這個城市的原子，

is held together by the humble chemical bond.

經由不起眼的 化學鍵結合在一起。