CAS Number7439-91-0
PubChem CID23926
Atomic Radius187
Atomic Volume22.5
Atomic Weight138.905
Boiling Point3,464
Bulk Modulus
Crystal StructureSimple Hexagonal
Covalent Radius207
Electrical Resistivity
Electron Configuration[Xe] 5d1 6s2
Electrons per shell2, 8, 18, 18, 9, 2
Heat of Fusion6.2
Heat of Vaporization400
Ionization Potential5.577
Magnetic Ordering
Magnetic Susceptibility
Mass Number57
Melting Point920
Atomic Number139
Oxidation States2, 3
Poisson Ratio
Shear Modulus
Specific Heat Capacity0.195
Thermal Conductivity0.135
Van der Waals radius
Young's Modulus
Abundance in Earth's crust0.0034%
Abundance in Universe2×10-7%
La Lanthanum 57 138.90547 3 6 f 57 920.0 3454.0 [Xe] 5d1 6s2 2 8 18 18 9 2 6.15 0.0034% Silver Hexagonal 1.1 {"1":"538.1","2":"1067","3":"1850.3","4":"4819","5":"5940"} 538 48 169 3 1.38 22.5 11.3 399.57 0.19 13.5 0 Solid, Conductor, Lanthanide, Stable, Natural LAN-the-nem Soft, silvery-white, malleable, ductile metal. It is used in the electodes of high-intensity, carbon-arc lights. Also used in the production of high-grade europium metal. Because it gives glass refractive properties, it is used in expensive camera lenses. Found with rare earths in monazite and bastnasite. Monazite sand typicall contains 25% lanthanum. Q21clW0s0B8 Lanthanum
Jędrzej Śniadecki isolated the element in 1807, but his work was not ratified.

Jöns Berzelius and Gottfried Osann nearly discovered ruthenium in 1827.

In 1844, Karl Ernst Claus confirmed that there was a new element and isolated ruthenium from the platinum residues of the rouble production while he was working in Kazan University, Kazan. From the Latin word Ruthenia, Russia 57 1839 Carl Gustaf Mosander Sweden From the Greek word "lanthanein" meaning "to lie hidden"

Isotopes of Ruthenium

Standard Atomic Weight


Stable Isotopes

138La 139La

Unstable Isotopes

117La 118La 119La 120La 121La 122La 123La 124La 125La 126La 127La 128La 129La 130La 131La 132La 133La 134La 135La 136La 137La 140La 141La 142La 143La 144La 145La 146La 147La 148La 149La 150La 151La 152La 153La 154La 155La

Ruthenium is a suspected carcinogen and its compounds strongly stain the skin
Ruthenium is unaffected by air, water and acids
Ruthenium is used in platinum and palladium alloys to make wear-resistant electrical contacts.

Ruthenium dioxide and lead and bismuth ruthenates are used in thick-film chip resistors.

Fountain pen nibs are frequently tipped with alloys containing ruthenium.

Ruthenium is a versatile catalyst.