Post-transition metal defined transition elements as finishing at group 10 (nickel, palladium and platinum), therefore excluding group 11 (copper, silver and gold), and group 12 (zinc, cadmium and mercury). A survey of chemistry books in 2003 showed that the transition metals ended at either group 11 or group 12 with roughly equal frequency. Where the post-transition metals end depends on where the metalloids or nonmetals start. Boron, silicon, germanium, arsenic, antimony and tellurium are commonly recognised as metalloids; other authors treat some or all of these elements as nonmetals. The diminished metallic nature of the post-transition metals is largely attributable to the
Germanium disulfide Germanium disulfide Germanium disulfide or Germanium(IV) sulfide is the inorganic compound with the formula GeS. It is a white high-melting crystalline solid. The compound is a 3-dimensional polymer, in contrast to silicon disulfide, which is a one-dimensional polymer. The Ge-S distance is 2.19 Å. Germanium disulfide was the first germanium compound found by Clemens Winkler, during the analysis of argyrodite. The fact that germanium sulfide does not dissolve in aqueous acid made it possible for Winkler to isolate the new element. Germanium disulfide is created by reacting hydrogen sulfide with germanium tetrachloride in a concentrated hydrochloric acid solution. Natural GeS