 Okay, this one says identify the Lewis acids and bases in the following reaction. So remember Lewis acids are often different than Bronsted-Lowry acids, okay? So Lewis acids will have an empty orbital where lone pair electrons are being donated into. So if we think about these two particles making this particle here, okay, this molecule or this ion, sorry, has no electrons, right? But it's got an empty 1s orbital. This ion here of course has electrons and it's around its oxygen, in fact that negative charge is formally put on that oxygen. If you want to think about putting your electrons around it, putting the charge where it's supposed to be, what's going to happen is these electrons are going to donate into that 1s orbital there. Okay, so when that happens we make this molecule water, okay, and we want to identify which one of these particles is the Lewis acid and Lewis base. Well, remember the Lewis base has the electrons and the Lewis acid doesn't, so this would be the Lewis base and this would be the Lewis acid. Do you have any questions on that one? Pretty straight forward, okay.