[Aufbau89]

There's no given problem.  I just don't understand what it means when a molecule is said to have a dipole moment.  Could someone please explain this to me ?  Explanations from more than one person will help a lot.  Thank you.   

[Borek]

Do you know dipole definition?

[DaveD]

A dipole moment arises from the fact that a pair of electrons in a covalent bond are often shared unequally, in particular when this bond is between two different atoms.  The more electronegative atom will have a greater electron density than the more electropositive atom.  The equal and opposite charges of magnitude \delta are separated by a distance l.  This separation of charge constitutes a dipole (two poles);  and the dipole moment \mu is equal to \delta times l.

[Aufbau89]

Hmm, so dipole moments basically occur when one of the atoms is more electronegative than the others?  This is only for covalent bonds?  Not ionic?  And what was that about delta, \mu, and distance?  I'm sorry for asking so many questions but i have a test next week and this is the topic I'm most unclear about.  Thanks for the great help so far!   

[Borek]

http://en.wikipedia.org/wiki/Dipole_moment

[Aufbau89]

Haha, wow, I feel so dumbfounded now.  Guess I should start using Wikipedia more often.  Thanks alot, all this have helped enough; sorry for the trouble.