A highly irritating, greenish-yellow gaseous halogen, capable of combining with nearly all other elements, produced principally by electrolysis of sodium chloride and used widely to purify water, as a disinfectant and bleaching agent, and in the manufacture of many important compounds including chloroform and carbon tetrachloride. Atomic number 17; atomic weight 35.453; freezing point -100.98°C; boiling point -34.6°C; specific gravity 1.56 (-33.6°C); valence 1, 3, 5, 7. See Table at element.
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.