(1) Zirconium, palladium, and ruthenium make up a metal that repairs itself.

(2) To this group belong the important steel alloying elements nickel and manganese, as well as cobalt and the inert metals ruthenium , rhodium, palladium, osmium, iridium and platinum.

(3) It is also classified with a group of similar metals, including ruthenium , rhodium, palladium, osmium, and iridium, with similar properties.

(4) Along with ruthenium , rhodium, osmium, iridium, and platinum, it belongs to the platinum group of metals.

(5) That porous layer, which contains stabilized zirconia and small amounts of the metals ruthenium and cerium, chemically and cleanly converts the fuel to hydrogen.