来自《耶鲁大学开放课程：新生有机化学 第2集 第2集》

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  Now here's a puzzle.
  问题来了
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  It's also true that BH3 reacts with BH3.
  BH3也能和BH3反应
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  That doesn't look like Lewis.
  这就和路易斯讲的不一样了
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  And the bond is reasonably strong,
  这个新键也蛮强
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  it's half as strong as a carbon-carbon bond.
  键能相当于碳碳单键的一半
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  So what's the glue that holds B2H6 together?
  是什么将B2H6连在一块儿的呢
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  And we'll come back to that fourteen lectures from now.
  再过14堂课我们会讲到这个
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  But there's another thing.
  现在要讲个其他的
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  There's bookkeeping that you do with Lewis structures
  根据路易斯式可以写出原子的形式电荷
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  to assign what's called formal charges; not real charges,
  这有点像记账 记下的电荷并不真实
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  just what charges you write in the formula,
  只是根据式子记下的电荷
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  and you hope they mean something.
  而你希望这具有某种意义