Germanium
. Germanium, symbol Ge, hard, brittle, grayish-white, crystalline semimetallic element. The atomic number of germanium is 32; it is in group 14 (or IVa) of the periodic table . The Russian chemist Dmitry Mendeleyev predicted the existence and chemical properties of germanium in 1871; because of its position under silicon in the periodic table, he called it ekasilicon. The element was actually discovered in the silver-sulfide ore argyrodite by the German chemist Clemens Alexander Winkler in 1886. Germanium is in the same chemical family as carbon, silicon, tin, and lead, and resembles these elements in forming organic derivatives such as tetraethyl germanium and tetraphenyl germanium. Germanium forms hydrides—germanomethane, or germane; germanoethane; and germanopropane—analogous to those formed by carbon in the methane series. The most important compounds of germanium are the oxide (germanic acid) and the halides. Germanium is separated from other metals by distillation of the tetrach