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Web ref.org: Chlorine
A few well done paragraphs on chlorine, with descriptions of the element and its properties. One nice feature is that any technical term has a link to help you better understand it.
Science Struck
Science Struck: Uses of Chlorine
Describes the basic properties of chlorine and lists examples of how it is used in water treatment, medicine, industry, and inside the human body.
Science Struck
Science Struck: Bromine vs. Chlorine
Compares the properties and uses of bromine and chlorine.