Ruthenium
Ruthenium, a white metallic chemical element belonging to the platinum group of metals. It is extremely resistant to acids, including aqua regia. However, it can be attacked by alkalies and, at high temperatures, by oxidizing agents. Ruthenium forms a large number of complex compounds.
Commercially, ruthenium is used to alloy platinum for jewelry to make it hard. It is also used in the petrochemical industry as a catalyst and in the electrical industry in contacts that must withstand hard wear.
Most ruthenium is obtained as a byproduct of processing ores of other metals. For example, ruthenium is obtained in the Sudbury district of Canada, from nickel-copper ores. Ruthenium was discovered by Karl Klaus in 1844 in Russia.
Symbol: Ru. Atomic number: 44. Atomic weight: 101.07. Specific gravity: 12.4. Melting point: 4,190 F. (2,310C). Boiling point: about 7,050F. (3,900C). It has 7 stable isotopes and belongs to Group VIII of the Periodic Table. Valences: 0, 1, 2, 3, 4, 5, 6, 7, 8.