Category: Transition metal
Atomic Number: 44
Period: 5 | Group: 8
Block: d-block
A platinum-group metal that hardens its neighbours and catalyses ammonia synthesis.
| Property | Value |
|---|---|
| Phase at STP | Solid |
| Density | N/A |
| Melting Point | 2607.00 K (2333.85 °C) |
| Boiling Point | 4423.00 K (4149.85 °C) |
| Heat Capacity | N/A |
| Property | Value |
|---|---|
| Atomic Mass | 101.0700 u |
| Electronegativity (Pauling) | N/A |
| Oxidation States | -2, 0, +1, +2, +3, +4, +5, +6, +7, +8 |
| Electron Configuration |
| Discovered By | Unknown |
|---|---|
| Discovery Year | 1844 |
| Named After | Latin Ruthenia, Russia |
Claims from platinum residues
In 1808 the Polish chemist Jędrzej Śniadecki reported a new metal, which he called vestium, in South American platinum ore, and in 1828 Gottfried Osann in Tartu reported ruthenium and other new metals in platinum from the Urals. Neither claim could be confirmed.
Klaus identifies ruthenium (1844)
In 1844 Karl Ernst Klaus (also written Claus), a professor at Kazan University, worked through the residues left after platinum was extracted from Ural ore. He isolated a new metal, showed that it was distinct from the known platinum metals, and kept Osann's name ruthenium, from Ruthenia, the Latin name for the Rus' lands (Russia).
The last platinum metal
Ruthenium was the last of the six platinum group metals to be identified, about 40 years after palladium, rhodium, osmium and iridium.
| ISOTOPE | Neutrons | Natural Abundance | Half-life | Decay Mode |
|---|---|---|---|---|
| Ru-96 | 52 | 5.54% | Stable | - |
| Ru-98 | 54 | 1.87% | Stable | - |
| Ru-99 | 55 | 12.76% | Stable | - |
| Ru-100 | 56 | 12.60% | Stable | - |
| Ru-101 | 57 | 17.06% | Stable | - |
| Ru-102 | 58 | 31.55% | Stable | - |
| Ru-104 | 60 | 18.62% | Stable | - |
| Ru-106 | 62 | - | 371.8 days | β⁻ |
Data: IAEA Nuclear Data Section, LiveChart of Nuclides, ground-state evaluations, retrieved October 10, 2026. Abundance is the share of atoms in the natural element; a dash means the isotope has no standard natural abundance.
Electronics
Chip resistors: thick-film resistors made with ruthenium dioxide are found on almost every circuit board.
Hard disk drives: a very thin ruthenium layer in the recording media helps store data at high density.
Contacts and chips: ruthenium plates electrical contacts, and chip makers are adopting it for the finest wiring layers of advanced processors.
Chemistry and industry
Chlorine production: titanium electrodes coated with ruthenium and titanium oxides are the standard anodes for making chlorine and caustic soda from brine.
Catalysts: ruthenium catalysts are used in some ammonia plants, in hydrogenation, and in olefin metathesis, the reaction of the Grubbs catalysts recognized by the 2005 Nobel Prize in Chemistry.
Alloys
Small additions of ruthenium harden platinum and palladium for jewelry and electrical contacts, improve the corrosion resistance of titanium, and strengthen some nickel superalloys used for jet engine turbine blades.
| Earth's Crust | N/A |
|---|---|
| Universe | N/A |