 So our next functional group is the carbonyl group, and with carbonyl groups we can have two families, aldehydes if the double bonded oxygen is on the end of the chain, and then something called ketones if the double bonded oxygen is in the middle of the chain. So let's look at some aldehydes and ketones. The simplest is something called methanol, and you can see with methanol we have the carbon with the double bonded oxygen attached to it, there's one carbon, we have our double bonded oxygen here, and then two hydrogens. Next would be ethanol, and with ethanol we have our double bonded oxygen attached to a carbon, and then you can see our second carbon has its regular three hydrogens attached. So third one of course would be propanol, and you see we have our three carbons, and then you see that the oxygen, double bonded oxygen is attached to the first carbon. So here's the first carbon, and we can flip the molecule this way, and you see this is still the first carbon, and there is our double bond. Now when we get to three carbons, we can actually have a ketone. So this is propanone, and you can see that our double bonded oxygen is attached to the second carbon. So the first carbon has three hydrogens, and it has a bond with the second carbon, the second carbon has the double bonded oxygen, that's our carbonyl group, and then our third carbon with its three hydrogens attached. So those are the first few of the carbonyl group.