Doc Brown's Chemistry Clinic: The Halogens: Includes an overview, general properties, reactivity trends, and information about the industrial electrolysis of sodium chloride solution.
The Chemistry of the Halogens: Covers their properties, methods of preparation, general trends, the hydrogen halides, and oxyacids of the halogens and their salts.
Visual Elements: The Halogens: Overview, general properties, and chemical data for the group.