Lone Pairs

[Andrew Berard 1F]

I think I missed the lecture that this was covered, but how do lone pair electrons affect bond angles? Thanks!!:-)

[Ignacio Ramirez 1J]

Bond angle is affected by the presence of a lone pair of electrons at the central atom. A lone pair of electrons at the central atom will always try to repel the bonded pair of electrons(Also called the lone pair repulsion). Therefore, the bonds are displaced slightly inside resulting in a decrease of the bond angle.

[Briana Lopez 4K]

A lone pair of electrons repels more than a bonded pair of electrons because LPE are less stable and have more energy. An electron bond and a lone pair are both considered regions of electron density, and regions of e- density repel. The LPE repel more which means that the bond angles will decrease because they are being pushed closer together by the LPE.
An example would be AX3 and AX2E1
Both have 3 regions of electron density, however one has a lone pair (E1) which means that the bond angles here will be smaller