Lewis Diagrams · 路易斯图
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| Lewis diagram/ˈluːɪs ˈdaɪəɡræm/ | 路易斯结构式 | lù yì sī jié gòu shì |
| octet/ɒkˈtet/ | 八隅体 | bā yú tǐ |
Drawing the electrons
- Chemists sketch molecules with dots and dashes.
- Each dot is a valence electron; each dash is a shared pair.
- From the sketch you can read a molecule's shape and behaviour.
- A few simple rules build the picture every time.
把电子画出来
- 化学家用点和短线勾画分子。
- 每个点是一个价电子;每根短线是一对共享电子。
- 从这幅草图你能读出分子的形状和行为。
- 几条简单的规则每次都能搭出这幅图。
Dots and lines
- A Lewis diagram 路易斯结构式 shows the valence electrons around each atom.
- A shared pair (a bond) is drawn as a line; unshared pairs as dots.
- Atoms aim for a full octet 八隅体 of 8 electrons.
点与线
- 路易斯结构式画出每个原子周围的价电子。
- 共享的一对(一个键)画成一根线;未共享的对画成点。
- 原子力求达到 8 个电子的完整八隅体。
Most atoms are stable with a full outer shell of ____ electrons (an octet). · 大多数原子在外层拥有完整的____个电子时是稳定的（八隅体）。
A full octet is 8 valence electrons. · 完整的八隅体是8个价电子。
In a Lewis diagram, a line between two atoms represents... · 在路易斯图中，两个原子之间的线代表...
One line is one bonding pair (2 shared electrons). · 一条线代表一个成键对（2个共享电子）。
Building the diagram
- Count the total valence electrons from all the atoms.
- Connect the atoms with single bonds, then complete each octet.
- Add double or triple bonds if the electrons run short.
搭建这幅图
- 数出所有原子的价电子总数。
- 用单键把原子连起来,再补全每个八隅体。
- 如果电子不够,就加双键或三键。
What is the first step in drawing a Lewis diagram? · 绘制路易斯图的第一步是什么？
You must know the total electron count before placing anything. · 在放置任何东西之前，你必须知道总电子数。
If single bonds leave a central atom short of an octet, you should... · 如果单键使中心原子未达到八隅体，你应该...
Multiple bonds share more electrons to complete the octet. · 多重键共享更多电子以完成八隅体。
When the octet bends
- Hydrogen is happy with just 2 electrons, not 8.
- Some atoms (like P and S) can hold an expanded octet of more than 8.
- Always start from the correct total electron count.
当八隅体被打破
- 氢只要 2 个电子就满足,而不是 8 个。
- 有些原子(如 P 和 S)能容纳超过 8 个的扩展八隅体。
- 始终从正确的电子总数开始。
Draw a Lewis structure · 绘制路易斯结构
Follow the steps to draw a valid Lewis diagram. · 按照步骤绘制有效的路易斯图。
Hydrogen should be given a full octet of 8 electrons in a Lewis diagram. · 在路易斯图中，氢应该获得完整的八隅体，即8个电子。
Hydrogen holds only 2 electrons, never 8. · 氢只容纳2个电子，绝不是8个。
Draw $\text{CO}_2$.
- Valence electrons: C(4) + 2 x O(6) = 16.
- Two C=O double bonds give carbon and both oxygens a full octet.
画出 $\text{CO}_2$。
- 价电子:C(4) + 2 x O(6) = 16。
- 两个 C=O 双键使碳和两个氧都达到完整八隅体。
How many valence electrons does $\text{CO}_2$ have? (C = 4, O = 6 each) · $\text{CO}_2$有多少个价电子？（C = 4，O = 6 各）
$4 + 2\times6 = 16$ valence electrons. · $4 + 2\times6 = 16$的价电子数。
Count the total valence electrons first and make your diagram use exactly that many -- no more, no less. Hydrogen never takes more than 2 electrons, so never give it an octet. When single bonds leave an atom short, add a double or triple bond rather than extra lone pairs.
先数出价电子总数,让你的图恰好用这么多——不多也不少。氢从不取超过 2 个电子,所以绝不要给它一个八隅体。当单键让某原子电子不足时,加一个双键或三键,而不是额外的孤对电子。
A Lewis diagram draws valence electrons as dots and bonds as lines, with atoms reaching a full octet. Count all valence electrons, join atoms with single bonds, complete the octets, and add multiple bonds if electrons are short. Watch the exceptions: hydrogen stops at 2, and some atoms expand past 8.
路易斯结构式把价电子画成点、把键画成线,原子力求达到完整八隅体。数出所有价电子,用单键连原子,补全八隅体,电子不够就加多重键。注意例外:氢止于 2 个,而有些原子会超过 8 个。