Ruthenium

"Ruthenium ( /ruːˈθiːniəm/ roo-thee-nee-əm) is a chemical element with symbol Ru and atomic number 44. It is a rare transition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is inert to most chemicals. The Russian scientist Karl Ernst Claus discovered the element in 1844 and named it after Ruthenia, the Latin word for Rus' (ancient Russia). Ruthenium usually occurs as a minor component of platinum ores and its annual production is only about 20 tonnes.^[3] Most ruthenium is used for wear-resistant electrical contacts and the production of thick-film resistors. A minor application of ruthenium is its use in some platinum alloys."

"Ruthenium has four crystal modifications and does not tarnish at normal temperatures. Ruthenium dissolves in fused alkalis, is not attacked by acids but is attacked by halogens at high temperatures. Small amounts of ruthenium can increase the hardness of platinum and palladium. The corrosion resistance of titanium is increased markedly by the addition of a small amount of ruthenium."

"This metal can be plated either by electroplating or by thermal decomposition methods. A ruthenium-molybdenum alloy is known to be superconductive at temperatures below 10.6 K."