text: why are group 7a elements called halogens? please do not copy and paste wikipedia's definition of:  "the term halogen was coined to mean elements which produce salt in union with a metal. it comes from 18th century scientific french nomenclature based on erring adaptations of greek roots."  ...because that explaination didn't sufficiently explain how the world "halogen" came about.    thanks much in advance! well  as wikipedia mentions: "the term halogen was coined to mean elements which produce salt in union with a metal"  in greek "alas" is salt and "genno" means to give birth to  as roots with latin characters they are spelled a bit differerently, so you have the "halo-" part for salt and -"gen" for giving birth to.   so halogens were named after their property to react with metals, producing salt, like oxygen was named after its property to produce acid  (oxos=acid) and hydrogen  (hydor=water) to produce water.  the first halogen to be discovered was chlorine, by carl wilhelm scheele in 1774. however scheele believed it was a compound containing oxygen and in 1810 sir humphry davy proved that chlorine was actually an element.  i don't know though, when and who exactly came up with the term "halogen".