 So let's do this next problem, sulfur dioxide. So again, in these problems, I think it's probably best to go by the rule least electronegativity in the middle rule. If you recall, sulfur is below oxygen, so it will have a less of electronegativity. So sulfur, oxygen, oxygen. Just do the exact same thing as we did before, OK? We're going to just put the correct amount of electrons in relation to the Lewis structure or the Valens electron. So oxygen's going to have 1, 2, 3, 4, 5, 6. Oxygen has 1, 2, 3, 4, 5, 6. Sulfur also has 6, OK? But in this case, hopefully you notice, sulfur is missing two electrons, OK? But oxygen needs two electrons, and oxygen needs two electrons, OK? So since sulfur normally could only take two electrons and we know this compound exists, we also know that sulfur must be expanding its valence. This is what we have to assume, OK? Is everybody OK with that justification? OK, so once you get by that, once you come to terms with that, then all it is is just doing the exact same thing as we did before, OK? Just like connecting bonds by sharing electrons, OK? So in this case, this oxygen needs to complete its octet, and this oxygen needs to complete its octet. The sulfur is going to go over its octet to expand its valence, OK? So when it does that, we're going to show the double bonds here, so like that, like that. So hopefully you think that's weird that sulfur is making those bonds with those electrons that are seen to be already in there. But again, why is it doing that? Because it's expanding its valence, OK? So it does something like that. Everybody OK with that? So double bond and double bond on each side of that sulfur. We've got to also put our lone pairs. So what would we expect the bond angle to be here? Would we expect it to be 180? No, why not? Because we have how many electron groups? Three, right? So what would we expect the bond angle to be? 120 might be a good expectation. In fact, it should be a tiny bit less than 120. Why? Because one of those electron groups is a lone pair, and that kind of squishes the bond angle down, OK? It's not an angle that I want you to remember, but it's something that you want to think about what should the angle be kind of around, OK? So let's draw what the molecular structure should look like, OK? So, well, first off, let's just make a table like we did before. So number of electron groups, how many? Guys, around the central sulfur, three. So if I have three, what's the electronic structure called, trigonal planar? Is the molecular structure trigonal planar? It's got to be bent, right? It can't be trigonal planar. Why? Because it would have to have how many atoms around the central sulfur? Three, right? So since it's only got two, it's got to be bent. So this is not what the molecule looks like, right? It actually looks kind of like something else, right? So it looks like the molecular structure looks like the sulfur does. So is everybody OK with doing something like this? This is a molecule with expanded valence. Any questions on something like this? So what I'd like you guys to do is go through that review sheet, look at the ones with expanded valence, attempt them on your own, OK? If you're having hard time with them, then either come to review session on Friday or we could go over one next Monday or something like that, OK?