VSEPR angles

[663697]

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If VSEPR is based on the repulsion of electrons, why does a bent tetrahedral molecule like water have a smaller angle (104.5) compared to a normal tetrahedral molecule like CH4 (109.5)? Shouldn't the repulsion of the electrons in H2O increase the angle?

 

[rabbott1971]

The lone pair pushes harder, making the angle less. In other words, its bent more from a lone pair than it would be if there had been a bonding pair in the same location.