 What I would like to do now is go over saw horse projections and specifically saw horse projections of ethyne. So what I have on the board, what I have written on the board here is the molecule ethyne and the way the structural representation, the way that you're used to seeing it at this point in time, right? So here in my hand, I have a ball and stick model of ethyne. So hopefully everybody can see, right, that the black balls here are carbon atoms, the white ones are hydrogen atoms, C2H6 like what we would think that thing would be. And remember we talked about how you can freely rotate around sigma balls. So do you see me doing that? Any questions about that? For your rotation? So you can see that happen. If I were to take this model here, and remember this doesn't show any directionality to it, where the 109.5 degree angles are concerned. Right? If we wanted to do that, we would draw it. And then hopefully we can see that representation like that with the 109 degree bond angles. But what we really want to do is show these saw horse projections. So the saw horse projection is very similar to this. It's just rotated from this projection to a projection like this. Okay? So hopefully you all can see that, right, that the saw horse projection shows this carbon in front being this carbon in front with this hydrogen being here and this hydrogen being here. This hydrogen being down there. And then hydrogen 1, hydrogen 2, hydrogen 3. And then remember what we said. We can rotate around sigma balls. So we're going to rotate like that. And we're going to show it again like that. So hopefully you guys can do that same procedure that we did over there and identify which carbons and which hydrogens we're looking at. And last thing I want to show you is that when the hydrogens are in front of each other, when we're looking at the model set of the ethane molecule, right, when the hydrogens are directly in front of each other, we call that eclipse. So with the saw horse projection looking at it like that, that's an eclipse saw horse projection. And the opposite of eclipse, right, it looks like that, is called a staggered projection. Okay? Or a staggered one. So this is a staggered and eclipsed saw horse projections. So if we look at that, that's it. Questions?