 On most occasions, spectra will include this TMS, trimethylsilane, which is at the zero mark as a standard reference point, so you will sometimes see just a little peak at the zero mark, which is just telling you that the standard has been used. What happens then is the numbers will move away from that zero mark to the left on the x-axis, and the sharp peaks will correspond to particular carbons or hydrogens within the molecule. What we'll know is that every different peak represents a different environment. For carbon, that's easy because it starts to tell us how many different types of carbons there are at an absolute minimum. As I said, two peaks means a minimum of two carbons and potentially more, and the hydrogens will split into those little peak clusters, and those will tell us about how many different hydrogens there are in the neighboring atom. Spectra also help to identify some aspects of the structure of the molecule. They may not always be definitive, and we may again need to use NMR in partnership with other data in order to make exact conclusions, but at least we can get some general ideas. And if all of the carbon environments in a particular molecule were identical, then we may simply have a single peak. So don't forget, the peaks are just telling us about a different type of environment, and if that environment occurs several times in the molecule, it'll still only show us that one peak. So here's another one just for comparative purposes, and you see this time we do have the TMS identified. So again, you can see that there's a peak that's occurring here around the 17-18 mark, and another one that's occurring up here around the 37-38 mark. So we would need to go and have a look at these in order to try and get an idea of what we're actually looking at. One of these is actually corresponding to a carbon environment which contains carbon-hydrogen bonds, and one of these is telling us that there is actually a bond to a halogen present in the molecule. Again, it doesn't tell us if there are other places in this molecule where this occurs. All it is doing is giving us a bit of an idea about how many different types of environments there are. And again, two peaks means we know that there is at least two carbons, two plus carbons, and in this case, there are only the two. So that's sort of telling us about the two different types of environments and the types of bondings that we can see that are present there. To get a little bit more information, we look at the proton NMR, and you'll notice here that we've labeled the hydrogens to give us a little indication about what's going on. Now interestingly enough, if this was ethane rather than chloroethane, then you would notice that that carbon-chlorine bond would disappear. We actually have symmetry then, so each carbon would be bonded to another carbon that's bonded to three hydrogens, and so you would not see one of both of these double peaks in these two outputs. But because of that chlorine is there, that means that we have one carbon where the hydrogens are attached to a neighbor with three hydrogens, and therefore that is going to produce an output with four peaks, so three plus one is four. And of course, the other carbon has a neighbor which has two hydrogens and a chlorine, and the chlorine is not going to be part of this, but the hydrogens will, so therefore if we count the number of hydrogens over here, we have two plus one, which gives us three of these little cluster peaks all together. So that's how we can put this information together. NMR is probably the most complex of the spectroscopy techniques, and I have sped through it, so we've looked at it in very, very broad detail. I know that we can look at some more of these in a little bit more detail, and actually start to get an idea of how we solve some of these problems in more examples in class. So thanks for watching.