Why is the repulsion between lone pairs and bonded pairs stronger than the repulsion between the bonding pairs and the bonding pairs? [duplicate]








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[why are lp-lp repulsions greater than bp-lp and bp-bp?](/questions/32211/why-are-lp-lp-repulsions-greater-than-bp-lp-and-bp-bp)

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> My book says "The reason for this difference is that the electron pair in a bond is further from the nucleus of the central atom than the electron pair in a lone pair." 
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I don't get it , how does the distance make any difference ?
I'm , taking AS level chemistry 




From Coulomb's law [Wikipedia](https://en.m.wikipedia.org/wiki/Coulomb%27s_law)
$$\pu{ F \propto \frac{1}{r^2} }$$
If your electrons are closer to the center then the distance between them is small.   

A small distance would lead to a greater repulsive force as the dependence of force is inverse square to distance between charges. 


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I dont understand exactly the quote either, maybe because it is isolated from the rest of the text but one way to see this is by observing that an electron pair in a bond is "trapped" between the two nuclei. Hence, it wont be able to expand too much in space. In contrast a lone pair is constrained only by one nucleus. Hence, it is more likely to be found further away in space compared to a bonded pair. Hence a lone pair which is nearby a bonded pair will push that bonded pair further away compared to another bonded pair. This is the reason why the H-N-H angles in NH3 are smaller than the H-C-H ones in CH4.


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