The Halogens Fluorine, Chlorine, Bromine, Iodine and

The Halogens Fluorine, Chlorine, Bromine, Iodine and Astatine 

Archaeological evidence for the use of rock-salt Written records on salt (ascribed to Herodot) 

Strabo described dyeworks for obtaining tyrian purple (dibromoindigo) in his Geographica Use of salt to purify noble metals 

Dilute hydrochloric acid prepared by Arabian alchemist Rhazes 

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Group VII, the halogen group The halogens (fluorine, chlorine, bromine, iodine, and astatine) are the most strongly non-metallic elements. They are very reactive chemically, and form many compounds. Their chemistry is discussed in Chapters 9 and 13. 

Calcium reacts with the halogens— fluorine, chlorine, bromine, iodine, and astatine. The halogens are the elements that make up Group 17 (VIIA) of the periodic table. Calcium also reacts readily with cold water, most acids, and many non-metals, such as sulfur and phosphorus. For example, calcium reacts with sulfur ... 

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