[Aug803]

Hello, I have a question about lattice energy.

I understand that a "higher charge" increases lattice energy, while a large distance between the ions decreases lattice energy.

As far as I can tell, charge is usually the dominant factor.

Can anyone explain why AlBr3 has a higher lattice energy than CaO?

AlBr3: 3*1 = 3
CaO: 2*2 = 4

Shouldn't CaO have a higher LE?
Even if you account for the distance... Al may be smaller than Ca, but O is smaller than Br. So the difference in "d" is not very significant. I would assume CaO is higher based on charge, but that's just not the case.