Electronegativity and bonding · 电负性与键合
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| electronegativity/ɪˌlektrəʊŋɡəˈtɪvɪti/ | 电负性 | diàn fù xìng |
| nuclear charge/ˈnjuːklɪə tʃɑːdʒ/ | 核电荷 | hé diàn hè |
| ionic bond/aɪˈɒnɪk bɒnd/ | 离子键 | lí zi jiàn |
| covalent bond/ˈkəʊvələnt bɒnd/ | 共价键 | gòng jià jiàn |
| bond polarity/bɒnd pəʊˈlærɪti/ | 键的极性 | jiàn de jí xìng |
The tug-of-war for electrons
- Electronegativity 电负性 is an atom's power to attract the electrons in a bond towards itself.
- It follows a clear trend across the Periodic Table.
- The difference between two atoms tells you the bond type.
争夺电子的拔河
- 电负性(electronegativity) 是一个原子把 键中的电子 吸引向自己的能力。
- 它沿周期表遵循一个清晰的趋势。
- 两个原子之间的差告诉你 键的类型。
The power of an atom to attract the electrons in a covalent bond is its ______. · 一个原子把共价键中的电子吸引过来的能力是它的 ______。
It increases across a period and up a group (fluorine is the highest). · 它沿一个周期增大、沿一个族向上增大(氟最高)。
Electronegativity is: · 电负性是:
Electronegativity measures how strongly an atom pulls the shared bonding electrons towards it. · 电负性衡量一个原子把共享的成键电子拉向自己有多强。
What sets it, and the trend
- Three factors: nuclear charge 核电荷 (more protons → stronger pull), atomic radius (closer → stronger), shielding (more inner electrons → weaker).
- So it rises across a period and falls down a group.
- Fluorine is the most electronegative element.
什么决定它,以及趋势
- 三个因素:核电荷(更多质子 → 更强的拉力)、原子半径(更近 → 更强)、屏蔽(更多内层电子 → 更弱)。
- 所以它 沿一个周期上升 并 沿一个族向下下降。
- 氟(fluorine) 是电负性最高的元素。
Sharing a pair of electrons · 共享一对电子
Step through a covalent bond: two atoms overlap and share a pair so each reaches a full shell — when the two pull equally the bond is non-polar. · 逐步看一个共价键:两个原子重叠并共享一对电子,使各自达到满壳层——当两者拉力相等时,键是非极性的。
Electronegativity: · 电负性:
More nuclear charge and smaller radius across a period raise it; more shells down a group lower it. F is the highest. · 沿一个周期更多的核电荷和更小的半径使它上升;沿一个族向下更多的壳层使它下降。F 最高。
Which change increases an atom's electronegativity? · 哪个变化增大一个原子的电负性?
More protons (nuclear charge) pull the bonding electrons more strongly; radius and shielding lower it. · 更多的质子(核电荷)把成键电子拉得更强;半径和屏蔽使它下降。
Electronegativity rises across a period and falls down a group, so fluorine is the most electronegative element. · 电负性沿一个周期上升、沿一个族向下下降,所以氟是电负性最高的元素。
Across a period the radius shrinks and nuclear charge rises; down a group more shells weaken the pull. · 沿一个周期半径缩小、核电荷上升;沿一个族向下更多的壳层减弱了拉力。
Predicting the bond type
- A large electronegativity difference → an ionic bond 离子键.
- A small difference → a covalent bond 共价键.
- (We compare Pauling electronegativity values.)
预测键的类型
- 大的 电负性差 → 离子 键。
- 小的 差 → 共价 键。
- (我们比较 鲍林(Pauling) 电负性值。)
A large electronegativity difference between two atoms gives: · 两个原子之间大的电负性差给出:
A big difference means electrons are transferred (ionic); a small difference means they are shared (covalent). · 大的差意味着电子被转移(离子);小的差意味着它们被共享(共价)。
Match each electronegativity difference to the bond it gives. · 把每个电负性差与它给出的键配对。
The bigger the electronegativity gap, the more the electrons shift — from shared (covalent) to fully transferred (ionic). · 电负性差距越大,电子移动得越多——从共享(共价)到完全转移(离子)。
Trends in electronegativity
- Electronegativity increases across a period and decreases down a group.
- Fluorine is the most electronegative element; the trend predicts bond polarity 键的极性.
Electronegativity rises across a period and falls down a group — fluorine is the highest.
电负性的趋势
- 电负性沿一个周期 增大,沿一个族向下 减小。
- 氟 是电负性最高的元素;这个趋势预测键的极性。
电负性沿一个周期上升、沿一个族向下下降——氟最高。
You've got it
- electronegativity = power to attract bonding electrons
- set by nuclear charge, radius, shielding; rises across, falls down; F is highest
- large difference → ionic; small → covalent
你掌握了
- 电负性 = 吸引成键电子的能力
- 由 核电荷、半径、屏蔽 决定;沿周期上升、沿族下降;F 最高
- 大 差 → 离子;小 → 共价