All right. So this brings us to our first named reaction of this section. And it turns out that it's a really easy reaction, because it's just the one that we've already been practicing with. It's called Hydrology Nation. Okay. Just like the name says, all we're gonna be doing is we're gonna be adding a hydrogen and a halogen as signal bonds. That's it. Okay, so we just want to fill out a few facts before we begin. Let's talk about the intermediate, Okay? Because all these edition reactions, you're gonna have intermediates. Okay, so either intermediates or transition states. So let's go ahead and talk about what this is. The intermediate is gonna be a carbo Catalan. All right, so we know that we're gonna have a carbon cat and intermediate, and the stereo chemistry is gonna be unknown. Okay? The reason is because whenever you have a carb acadian in place and you're attacking it, remember that carbo Catalans are tribunal plainer. So what that means is that they have a front side and the back side that are both easy to attack. So what that means is that when something attacks it, I'm not going to know exactly where it's coming from. Is it coming from the front back? We don't really know. Structure. You're just going to get a mixture. Okay, so the product here is gonna be Oculus highlights. Okay, So what that means is I'm gonna go from double bonds toe alcohol. Hey, lights using Hydrology Nation. Now let's talk about rearrangements. This is basically a check box. Could we expect carbo kata and rearrangements are not ok? And the answer is that any time you have a car broke out and intermediate in your mechanism, you always need to be thinking about rearrangements. Alright, so this is going to get a huge check mark, because the fact that yeah, we have car broken into the intermediate, so we would expect that you have to be able to shift if it wants to. Okay, then finally we've got what we call the re geochemistry. Okay? I'm just gonna go ahead and to find this word really quick re geochemistry. And what Regio Kim has to do with is actually where the reactive site is. Where does the electrical add? Okay, so I'm just gonna put where does electric file add? Okay, that's the re geochemistry. The stereo chemistry says What's the shape of the end product? Is is this is a trans stuff like that regional Kemp says. Where does the ultra fault at does it add to a specific Adam? And the answer is yes. The re geochemistry is going to be more cough nick off because Markov Dickov's rule says that your carbon Catalan is going to form in the most stable place and that your electric file attacks your car broke a tie in. So that's the regional chemistry. Okay, let's go ahead and look at the general reaction, Okay? The general reaction is simply gonna be this. A double bond reacts with a HX hydrogen. Hey, lied. And what we're gonna wind up getting is that if it's asymmetrical, your halogen is gonna attached to them or substituted side or the mark Avakov side. So that would be Is this right here? And then your hydrogen is gonna attack to the less substituted side. So that would be this hydrogen right there. Now, you might be wondering what is the squiggly line If you've never seen that before. Okay, Maybe you have. Maybe you have it squiggly line, just has to do with the unknown stereo cam. Okay. Basically, all that saying is that I don't know if the hydrogen is facing towards the front. I don't know if it's facing towards the back, because when it attacked, it was trickle plainer, so I don't really know exactly where it iss. Okay, now notice that if that h not ages there, there's actually no Carol center on this molecule it all. So what that means is that this X that I just drew here, I could have drawn it on the front. I could have drawn it in the back. It doesn't really matter. I'm trying to show you. Is that honestly, we're not going to know the stereo chemistry of the end product. Okay, so there you go. Pretty easy. Let's go ahead and do an example of this. I want you guys to try it yourself, and then I'll go ahead and give you guys the answer