 OK, so let's do this problem. It says, what type of intermolecular forces would you expect to exist between molecules CBR4? So if I have a bulk solution or a bulk substance, carbon tetra bromide, what forces would two carbon tetra bromide molecules feel between each other? What intermolecular forces? So the first thing you want to do in these problems is identify the types of intermolecular forces that could be present. So BR and C, of course, we're going to have a polar bond between them. But BR is not electronegative enough to have hydrogen bonds. Not to mention, there's no hydrogens in this molecule. So we're really at the point of deciding, is this a polar or a non-polar molecule? Can anybody help me out? Is that going to be a polar or non-polar molecule? Non-polar, right? So let's just draw this molecule. And we'll draw it in Vesper theory, just to show the non-polarity. Have a dipolarum, dipolarum, dipolarum, and dipolarum. They're all pulling opposite of each other and to equal extent, so they cancel each other out. So the overall dipole moment of this molecule is 0. Is everybody OK with that? So that means this molecule is a non-polar molecule, like you were saying. So since this is a non-polar molecule, it can't have dipole-dipole interactions. Does everybody understand that? You need a dipole to have those types of interactions. So the only types of interactions that carbon tetra bromide could have with another carbon tetra bromide is the most minimal, OK, the dispersion forces, or London forces, OK? So we were to classify what intermolecular interactions between molecules of carbon tetra bromide, we would say dispersion forces, OK? Dispersion or London forces, whichever one you like.