 So the next thing you're going to be learning about is Vesper theory. So Vesper theory is valence shell electron pair repulsion theory. And that just tells you that if you've got a central atom, like we do here in the carbonate ion, right? So this is the Lewis structure of the carbonate ion. This is not how the molecule or the particle actually looks, OK? So this is how it's bonded together like we just showed. But the bond angles aren't appropriately shown, OK? So what you need to know is that the Lewis structure and the Vesper structure are actually two different structures, OK? So when it asks for Lewis structure, it's asking for something like this. When it's asking for Vesper theory or the Vesper structure, it wants you to show the bond angles in the appropriate manner, OK? So what you find here is that, so in the case of Vesper theory, single bonds, double bonds, and triple bonds are all treated the same as one bond, OK? So if we look here around this carbon atom, right? We have three bonding regions. Do you guys understand what I'm saying? So we're treating them all single bonds, double bonds, triple bonds as one bond, OK? So we can call them bonding regions. It might be easier for us, OK? So if I look at one, two, three bonding regions around that atom, OK? Is everybody OK with what I'm saying? So remember, atoms are spheres, OK? So the furthest you can get away from each other on a sphere, because remember electrons hate each other. They're all negatively charged, so they want to be pushed as far away from each other as possible, OK? The furthest you can get away from each other, if you only have three lines, or three areas of electron density, is a bond angle of 120 degrees away from each other, right? So if I look at this, right? This would imply that I have a bond angle of 180 degrees there, right? Does everybody understand what I'm saying? And a bond angle of 90 degrees there, which is not the case, OK? It's the case that these electrons want to get as far away from each other as possible, so in order to do that, they have to get 120 degrees away from each other, OK? So let's go ahead and draw the Vesper structure, OK? Or the actual particle structure. So that's the same. But we want to draw these kind of like a, I don't know, peace signer or savings symbol or something, OK? So you guys see the difference between the two drawings? OK, so this Vesper drawing actually shows that bond angle being 120 degrees, which you would expect because there's three bonding or regions of electron density. Is everybody OK with that? So let's just, for example, go back to our example of carbon dioxide, right? Carbon dioxide, do you guys remember building that earlier? So we built carbon dioxide. And the Lewis structure we said looked like this. Do you guys remember that? So how many regions of electron density do we have around that central carbon atom? How about you guys tell them? Two, right? Two. So what's the furthest apart two regions of electron density could get on a sphere from each other? 180 degrees, OK? So in fact, this Lewis structure of carbon dioxide looks exactly the same as the Vesper structure, OK? So let's just draw that Vesper structure or the actual structure. And we see a bond angle being 180 degrees. Why? Because that's the furthest away two things get from each other on a sphere. Does everybody understand what I'm saying? Let's kill this video. Are any questions about this before we do? OK.