ruthenium

A hard silver-white acid-resistant metallic element that is found in platinum ores and is used to harden platinum and palladium for jewelry and in alloys for nonmagnetic wear-resistant instrument pivots and electrical contacts. Atomic number 44; atomic weight 101.07; melting point 2,334°C; boiling point 4,150°C; specific gravity 12.1 (20°C); valence 0, 1, 2, 3, 4, 5, 6, 7, 8. cross-reference: Periodic Table.

Chemical symbol, Ru; atomic weight, 103.5 (Claus). A metal of the platinum group.

A rare element of the light platinum group, found associated with platinum ores, and isolated as a hard, brittle steel-gray metal which is very infusible. Symbol Ru. Atomic weight 103.5. Specific gravity 12.26. See Platinum metals, under platinum.

a metallic chemical element (symbol Ru) with an atomic number of 44.

a rare polyvalent metallic element of the platinum group; it is found associated with platinum