Halogen
WordNet

noun


(1)   Any of five related nonmetallic elements (fluorine or chlorine or bromine or iodine or astatine) that are all monovalent and readily form negative ions
WiktionaryText

Etymology


From + , referring to elements which produce a salt in union with a metal.

Noun



  1. Any element of group 7, i.e. fluorine, chlorine, bromine, iodine and astatine, which form a salt by direct union with a metal.
 
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