Bond Angles

[VGonzalez]

Will we be asked for bond angles on shapes like trigonal pyramidal? Should we just memorize the generic angles of 109.5?

[Sameen Mahmood 3D]

Considering they're always being brought up not just in lectures but also discussions and homework, I definitely think we'll be asked for bond angles for all structures.

[Alexa_Henrie_1I]

So the best way to know the angles is just through memorization of the structures right?

[Fayez Kanj]

Hey!

Yes, you need to memorize the bond angle of 109.5 for any tetrahedral molecule geometry. However, when there are shapes that are trigonal pyramidal ( 3 bonding pairs and 1 lone pair), you do not need to know the angles, just that they will be slightly less that 109.5. A good rule of thumb is that for every lone pair of electrons, subtract 2-3 degrees.

Hope this helps :)