Dipole Moments and Shape

[Laila Alkhouri 3H]

How does molecular shape or geometry affect the presence or absence of a dipole moment? I know when we discussed shape we talked a little bit about dipole moments and now I am getting confused on how the geometry affects them or if its the other way around.

[Kamara Lindsey]

Hi, I sort of think of a dipole moment as a tug-of-war between atoms for electrons. If the molecule is shaped in a way that the tugs balance out, it's like a tie in the game, and the molecule is nonpolar. But if one side is winning more in this electron tug-of-war because of the shape, the molecule ends up polar.

So, it's a combination of the individual bond tugs and how the team is arranged. If it's a fair game all around, no dipole moment; if it's lopsided, you've got a dipole moment.

Hopefully, that kind of makes sense!