CK-12 Foundation
Ck 12: Physical Science: Unsaturated Hydrocarbons
[Free Registration/Login may be required to access all resource tools.] Definition of an unsaturated hydrocarbon and the different types.
Wikimedia
Wikipedia: Functional Group
Encyclopedia entry for functional groups that, in in organic chemistry, are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules.
Science Struck
Science Struck: What Is a Bromine Test?
Explains what a bromine test is, the chemistry behind it, what it is used for, and gives examples of bromine test strip brands that are used for test the water in swimming pools and at spas.