Halogens
Links
Doc Brown's Chemistry Clinic: The Halogens
http://www.wpbschoolhouse.btinternet.co.uk/page03/The_Halogens.htm
Includes an overview, general properties, reactivity trends, and information about the industrial electrolysis of sodium chloride solution.
Visual Elements: The Halogens
http://www.chemsoc.org/viselements/pages/data/intro_groupvii_data.html
Overview, general properties, and chemical data for the group.