Ruthenium (Ru)


  • Symbol: Ru
  • Atomic Number: 44
  • Atomic Weight: 101.07
  • Element Classification: Transition Metal
  • Discovered By: Karl Ernst Claus
  • Discovery Date: 1844
  • Name Origin: Named after Russia (Ruthenia in Latin)
  • Density(g/cc): 12.45
  • Melting Point: 2334°C
  • Boiling Point: 4150°C
  • Appearance: Hard, white, and brittle metal
  • Atomic Radius(pm): 178


Ruthenium was discovered in 1844 by the Baltic German scientist Karl Ernst Claus at the University of Kazan, Russia. Claus isolated ruthenium from the platinum ores found in the Ural Mountains. He identified it as a new element through its distinct chemical properties and named it after Ruthenia, the Latin word for Rus’, referring to Russia, to honor the country where it was discovered.

Relation to Other Elements

Ruthenium is a member of the platinum group metals (PGMs), which includes platinum, palladium, rhodium, osmium, and iridium. These metals share similar physical and chemical properties, such as high melting points, resistance to corrosion, and catalytic abilities. Ruthenium is a transition metal, characterized by its ability to exist in multiple oxidation states and form complex compounds. It often exhibits oxidation states ranging from 0 to +8, making it versatile in catalysis and organometallic chemistry.

Natural Occurrence

Ruthenium is found in nature as a free metal alloyed with other PGMs and in nickel and copper ores. It is one of the rarest metals in the Earth’s crust. The majority of the world’s supply of ruthenium comes from the mining and processing of platinum and nickel ores, where ruthenium is obtained as a byproduct.


Ruthenium has various applications in industry and technology:

  • Catalysis: Ruthenium is used as a catalyst in chemical reactions, including hydrogenation and in the production of ammonia in the Haber-Bosch process.
  • Electronics: It is used in the electronics industry for chip resistors and electrical contacts due to its excellent conductivity and durability.
  • Chemical Industry: Ruthenium compounds are utilized as catalysts in organic synthesis, particularly in olefin metathesis reactions.
  • Jewelry and Decoration: Due to its hardness and resistance to tarnish, ruthenium is used for plating high-end jewelry and watch parts, giving them a dark, durable finish.
  • Energy: Ruthenium-based compounds are explored for use in solar energy conversion and as components of advanced fuel cells.

The discovery of ruthenium expanded the understanding of platinum group metals and their catalytic properties. Its uses in catalysis, electronics, and as a hardening agent for platinum and palladium highlight the value of this metal in various high-technology and industrial applications.

Rhodium (Rh)

Palladium (Pd)