Quick Facts
| Property | Value |
|---|---|
| Symbol | Ru |
| Atomic Number | 44 |
| Atomic Mass | 101.07 u |
| Category | Transition Metal |
| Period | 5 |
| Group | 8 |
| Block | d |
| Electron Configuration | [Kr] 4d⁷ 5s¹ |
Physical Properties
| Property | Value |
|---|---|
| State at 20°C | Solid |
| Density | 12.45 g/cm³ |
| Melting Point | 2334°C (2607 K) |
| Boiling Point | 4150°C (4423 K) |
| Appearance | Silvery-white, hard metal |
Atomic Properties
| Property | Value |
|---|---|
| Electron Configuration | [Kr] 4d⁷ 5s¹ |
| Electronegativity | 2.2 (Pauling scale) |
| First Ionization Energy | 710.2 kJ/mol |
| Atomic Radius | 134 pm |
| Covalent Radius | 146 pm |
| Van der Waals Radius | 207 pm |
History and Discovery
Discovered by: Karl Ernst Claus Year of Discovery: 1844 Location: Kazan, Russia
Etymology
Named after "Ruthenia," the Latin name for Russia, in honor of Karl Ernst Claus's homeland.
Discovery Story
Karl Ernst Claus discovered ruthenium in 1844 while analyzing platinum ore residues from the Ural Mountains. Earlier chemists, including Gottfried Osann, had detected signs of new elements in these residues, but Claus was the first to isolate and characterize ruthenium properly.
Isotopes
| Isotope | Natural Abundance | Half-life | Decay Mode |
|---|---|---|---|
| ⁹⁶Ru | 5.54% | Stable | - |
| ⁹⁸Ru | 1.87% | Stable | - |
| ⁹⁹Ru | 12.76% | Stable | - |
| ¹⁰⁰Ru | 12.60% | Stable | - |
| ¹⁰¹Ru | 17.06% | Stable | - |
| ¹⁰²Ru | 31.55% | Stable | - |
| ¹⁰⁴Ru | 18.62% | Stable | - |
Occurrence
Natural Abundance
Ruthenium is very rare, comprising only about 0.001 ppm of Earth's crust. It is found in platinum ores and as a native alloy with other platinum group metals. Major sources are South Africa, Russia, and North/South America.
Extraction and Production
- Byproduct: From platinum and nickel mining
- Refining: Chemical separation from platinum group metals
- Sources: South Africa (about 90% of production)
- Global production: about 30 tons annually
Applications and Uses
Electronics
- Thick-film resistors
- Electrical contacts
- Data storage (hard disk drive platters)
Catalysts
- Fischer-Tropsch synthesis
- Ammonia synthesis
- Organic reactions (Grubbs catalysts)
Chemical Applications
- Electrochemistry (dimensionally stable anodes)
- Dye-sensitized solar cells
- Corrosion-resistant coatings
Other Uses
- Fountain pen nibs (ruthenium alloys)
- Jewelry (ruthenium plating)
- Wear-resistant electrical contacts
Biological Role
Ruthenium has no known biological role. Some ruthenium compounds show anticancer properties in research.
Medical Research
Ruthenium complexes are being investigated as potential anticancer drugs and for photodynamic therapy.
Safety and Hazards
Toxicity
Ruthenium metal has low toxicity. Some ruthenium compounds can be toxic, particularly ruthenium tetroxide.
Handling Precautions
- Ruthenium tetroxide (RuO₄) is highly toxic and volatile
- Standard precious metal handling procedures
- Dust can be irritating
- Some compounds may be carcinogenic
Environmental Impact
Ruthenium is very rare and production volumes are low. It is contained in platinum group metal processing operations.
Interesting Facts
- Ruthenium is one of the rarest elements on Earth
- It is a member of the platinum group metals (PGMs)
- Ruthenium catalysts won the 2005 Nobel Prize in Chemistry (Grubbs metathesis)
- It can form compounds in 8 oxidation states (-2 to +8)
- Ruthenium-106 from nuclear accidents has contaminated parts of Europe