Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Ruthenium is a chemical element that has the symbol Ru and atomic number 44. A rare transition metal of the platinum group of the periodic table, ruthenium is found associated with platinum ores and used as a catalyst in some platinum alloys.This metal can be plated either by electroplating or by thermal decomposition methods. One ruthenium-molybdenum alloy has been found to be superconductive at temperatures below 10.6 K.