So the empirical formula is ch 20 multiplied by N, where N is basically any positive integer, any positive N value that is equal to three or greater. So the simplest monosaccharide contains an nvalue that is equal to three. And that means the simple monosaccharide consists of three carbon atoms, six H atoms and three oxygen atoms. Now, generally speaking, there are two types of categories of sugars. We have those sugars that contain aldehyde groups, and these are known as aldosis. And we have those sugars that contain a ketone group, and these are known as ketosis.