one of the ways to see if two molecules they're gonna be related to each other as stereo I summers is to look for something that we call Chire ality. So what is Kyra ality? Well, what kind reality says is this? Pirelli says if you look into a mirror and you get a different image than the image that of yourself, if you get a slightly different image and opposite image, then that means that you're gonna be a Cairo compound. That means that that image is going to be Cairo and it's gonna be different. And what we call that image is called non super imposible. Non super imposible is a really confusing way of just saying a different image. Okay, so I could give you a few different examples. So for example, um e look at my face in the morning when I see my face in the mirror and I'm brushing my teeth, it looks a lot like the face that I actually have. Okay, and that's because there's a line of symmetry in my face. So when I get the image back, I see the same exact image. Okay, so that would be something that that is called a Cairo because the images the same coming off of the mirror or at least it should be mostly the same as my face. Okay, Another example. That of something that is different would be like my hand. So my hand, I put it up against the mirror. The image I get is the opposite image. Okay, So that means that if I were to cut out the image that I see in the mirror and put it over my hand, I would get to opposite images. Okay. And that's the idea behind Chire ality. What Kyra Ality says is that if you get on opposite image when you look in the mirror, that is a Cairo compound. Okay, now the name for that different image. It has a really funky name that you're just going up to. No, and it's called an anant humor. Okay. And I could get really fun, depending on what your professors accent is like. But in Antium, er just means it's the mere image of a Cairo compound. Alright, So literally it could be anything. It does not to be a molecule. It could be ah, person. It could be a car. It could be Ah, cat whatever in an anti murders, just the mere image that's different. Okay, so here, let me show you guys an example with an actual molecule. Here's a molecule and what I want to show you is this, like, fake mirror that I drew. It's just this dotted line here. So imagine that this molecule, like I said, maybe it's like brushing his teeth in the morning. And it's looking at itself in the mirror. Okay, so has an eyeball. Obviously, this is just a really cool molecule. Alright, so it has an eyeball on. What does it see? Well, what it sees is okay, Well ah, lot of these. Ah, lot of the image looks the same. For example, what it sees is that the amine is towards the top. Okay, this is Let's say that's it's hair. Okay, so it's hair is at the top. He thinks everything is good so far, all right. And he also sees, for example, notice that I have some wedge and dash notation where wedge has to do with something. Being in the front and dash has to do with something being in the back. Okay, That means if this is a three d image, the dash should be behind and the Wedgwood be upfront. Okay, so what he see Is that okay? The hydrogen is still in the back. Cool. So this one is still in the back? Well, you know, everything looks fine, but then you notices Something's weird Where you notice is that well, the oh, age used to be on the right side, but in the image that he's looking back, the O. H. Is actually on the left hand side of himself. Okay, so it's like his hand or something. His hands on the other side of his body and then the same way with the metal group. The metal group used to be on the left, but now it's on the right. Okay, Now, I know this seems normal to you because you're thinking Oh, yeah, This is a mere So that means everything's gonna be flipped. Johnny, this isn't This shouldn't be new to you. This is just what happens when you look into a mirror. Alright. But that's all your professor wants. You know what your restaurants, you know, is that some molecules when they look in the mirror they're going to get that opposite image. Okay. What non super imposible means is that if I were to take a cut out of this thing, Okay, I'm gonna erase some stuff here so it becomes more clear I race the eyeball boo. Okay, when I take a cut out of this thing and lay it over this one, is it gonna look exactly the same? And the answer is No. Because even though the N H two would be in the same place and even though the age would be in roughly the same place because they're both facing towards the back, what I would get is that I would get O H over here, and I would get a C H three over here. And what that means is that these air non superimposed because my groups are in different places if I label overlay them over each other. Okay, so it turns out that we have a pretty easy rule that we can follow to test to see if something's gonna be Cairo or not. This is not the only way to figure it out, but it's just it's just like a rule that I already kind of hinted at. Which is this. If a molecule has an internal line of symmetry or anything, if anything has an internal line of symmetry, then it will have the same mere image. And if you have the same mere image, that's what we call a choir. That means it's not Cairo. It's not a Carol compound.