 Okay, let's show off the simplest organic molecule now. Remember what we talked about when something is an organic molecule relative to something not being an organic molecule. Do you remember what it had to have to be an organic molecule? Carbon-hydrogen bond, right? It had to have a carbon-hydrogen bond, okay? Because carbon dioxide, remember, is not an organic molecule, okay? So the simplest organic molecule is this, molecule CH4, it's called methane, okay? So of course we know hydrogen can make a little comedy bonds again, just one, right? So all these four hydrogens, since there's only one carbon, have to be around that carbon, remember? And we talked last time about carbon, you know, taking its S electrons and its P electrons and rehybridizing them to being all in SP orbitals. So remember when we talked about that, then we said, well, we can describe carbon and just put its electron, one electron on each side, right? So if we draw carbon, how many valence electrons does it have? Look at the period of a cable? Four. Four, right? So how do we draw it? We'll start at the top, one there, then go to the next side, one there, the next side, one there, the next side, one there, okay, so that's all four of them. And then hydrogen, we've got four hydrogens, right, each with one electron and one electron left in their shell, all right, let one space for an electron to be left in their shell. So hopefully you guys already could have built this, and then what are we going to do? Just fish up them together like that. So remember, Lewis structures of atoms, now we're going to draw the Lewis structure of methane, page four, so this is the Lewis structure. That doesn't show us anything about the geometry, right, if we look at that, we would think that that might be 90 degree bond angles, right, but we know it's not. What's the bond angles for that, do you guys remember, 109.5, right? So remember why is that, it's because, remember, atoms are spherical, right, they're not flat like a plate, okay, or a disc, so they're spherical, so remember those electron pairs hate each other, so they're trying to get as far apart from each other as possible, so instead of just being here and here, right, 90 degrees from each other, they can get further, and we all know that 109.5 is further than 90 degrees, right? So what happens is, this is the Lewis structure, we're going to represent it in a new sort of light, okay, it's called the Vesper structure, right, and that shows the valence shell electron pair repulsion, okay, so that's where this comes in, valence shell electron pair repulsion, they hate each other, right, so they want to be as far apart from each other as possible, so let's just draw, this is another way of calling the structural formula, okay or something like that, but notice this is not what, like square planar or whatever, right, do you guys remember what the shape this is called? Yeah, this is tetrahedral, so we've got that, you've already said, the 109.5 bond angle, remember, I said that this carbon rehybridized to being sp3 hybridized, so instead of having the 1s orbital and the 3p orbitals, okay, like it would normally have, they all mixed up and became sp3 orbitals, 4, okay, so as many orbitals as you put in, how many you get out, so you put in 1s and 3p orbitals, so you got out 4 sp3 orbitals, so let's look at these models now, so if we wanted to, we could look at the skeletal structure of methane and you can see quite easily that it is not square planar, right, it's got that bond angle there and if you measured it, it would be 109.5, but again, remember, this isn't really what a molecule looks like, but this gives us a good way of understanding what that bond angle is, why, because these types of models emphasize the bonds over the atoms, okay, and over the molecule itself. We can have these models where it emphasizes the atoms, right, so the relative size of the atoms, look how big carbon is relative to hydrogen, so that's what it looks like if you're looking at the relative size of the atoms, another representation of methane, and then of course the final representation of methane, a space billing model where the atoms are actually kind of stuck together, you know, and the electrons are shown to be all around that, okay, all around the molecule, so this is actually probably what methane looks like mostly, okay, it's mostly, it kind of looks more like a ball than anything, okay, doesn't really look like this, this emphasizes bonds, okay, so it depends on what model we want to use, it depends on what we want to emphasize to show which model we want to use if that makes sense, okay, is that okay? Are there any questions about this one? Questions? No? Okay, cool.