 So for those common ones, kind of a rule of thumb to recall, and you can think about those molecules that we've talked about previously, such as, I don't know, peryllium, hydride, boron, trifluoride, I think we talked about methane. This would be methane, ammonia, water. So do you remember the bond angles for these things? Can you guys help me out? How about approximate bond angles? So what's the bond angle for the two, right? The bond 180. 180. Thinking about methane. But these other ones are fairly similar, right? What's the angle of that thing? 1 on 9 and 1 half, right? So if you see something approximately 1 on 9 and 1 half, which I would include as 107.3, 104.5, it's a nice way, a nice rule of thumb, to realize that these things are going to be hybridized similarly. So if you see something that's got a bond angle of, well, 109.5 since we just did one of those, what was the hybridization of that carbon and that 109.5? SP3, OK? So SP3. So this, this, this are approximately the same angle. So what's going to be the hybridization of nitrogen and ammonia? SP3 and oxygen and water? SP32, OK? Not SP32, but SP3 as well, OK? So the F3, do you recall what hybridization it was? We did this last time. So we did the whole molecular orbital buildup. How many bonds is it making? Three. So what's its hybridization going to be? SP2, rule of thumb. If you see something that's got a bond angle of this, you can expect it to be this, OK? Is everybody OK with that? This, again, is just a rule of thumb, OK? The best way to go about this is to build up through molecular orbitals like we've been doing. But you don't have the time or whatever, you know? You see something, you know it's 120, then you can build it up afterwards and see if you're right. And what do you think this one's going to be? We did this one last time, yeah, SP. OK, so those are the common main group. Oh, and we can even do, well, so what's going to be the geometry around the central atom here? Blame it here. What about this one? Trigonal what? Planar. Why would it be trigonal planar and not trigonal perimodal? There's no valence electrons there, right? Because boron's one of those things that doesn't abide by the octane. And of course, for electronic structure, what would be the electronic structure for all of these? Tentrihesis, yeah. But then if we went to molecular geometry, right? This one would be tetrahedral. This one would be what? Perimodal, trigonal perimodal. And the electronic and the molecular geometry is the same. And this one they are, too. And these ones they're not. So this here, I guess, we're showing the molecular geometry. Any questions on that? Make sense? OK.