Answer:Both Aldehydes and ketones contain a carbon with a double bonded oxygen attached. The difference between the two molecules is that an aldehyde has at least one hydrogen directly attached to the carbon with the blue star next to it and a ketone does not. Instead, a ketone has two carbons attached to the carbon with the blue star attached (one on either side). Please note that in both molecules the carbon chains can be as long as you would like. For example, the carbon chains can contain one carbon or 100 carbons. Additionally, in a ketones, the two carbon chains can be of different lengths but do not have to. Finally, an aldehyde does not have to have a carbon chain directly attached to the carbon with the double bonded oxygen. Instead, it can have another hydrogen directly attached to the other side of the carbon. This molecule is the most basic aldehyde and is called Formaldehyde (seen below).
