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Wednesday, June 22, 2016

Ruthenium chemical element

Ruthenium was discovered in 1844 by Karl Karlovich Klaus.
The chemical symbol for ruthenium is Ru and its atomic number is 44.
We find it listed in the periodic table of elements in group 8 and period 5 and block d.
Ruthenium belongs to the family of transition metals such as for example the Silver, the Bohrium, cadmium, ...
This element is stable.
Ruthenium as a name came from the latin word Ruthenia which means Russia.

Ruthenium chemical element


Atomic number (Z) 44
Group, block group 8, d-block
Period: period 5
Element category: transition metal
Standard atomic weight (±) (Ar) 101.07(2)
Electron configuration [Kr] 4d7 5s1
per shell: 2, 8, 18, 15, 1

Physical properties
Melting point: 2607 K ​(2334 °C, ​4233 °F)
Boiling point: 4423 K ​(4150 °C, ​7502 °F)
Density near r.t. : 12.45 g/cm3
when liquid, at m.p. 10.65 g/cm3
Heat of fusion: 38.59 kJ/mol
Heat of vaporization: 619 kJ/mol
Molar heat capacity: 24.06 J/(mol·K)

Atomic properties
Oxidation states: -4, -2, 1, 2, 3, 4, 5, 6, 7, 8 ​(a mildly acidic oxide)
Electronegativity: Pauling scale: 2.2
Ionization energies 1st: 710.2 kJ/mol
2nd: 1620 kJ/mol
3rd: 2747 kJ/mol
Atomic radius empirical: 134 pm
Covalent radius: 146±7 pm

Crystal structure: ​hexagonal close-packed (hcp)
Speed of sound thin rod: 5970 m/s (at 20 °C)
Thermal expansion: 6.4 µm/(m·K) (at 25 °C)
Thermal conductivity: 117 W/(m·K)
Electrical resistivity: 71 nΩ·m (at 0 °C)
Magnetic ordering: paramagnetic
Young's modulus: 447 GPa
Shear modulus : 173 GPa
Bulk modulus: 220 GPa
Poisson ratio: 0.30
Mohs hardness: 6.5
Brinell hardness: 2160 MPa
CAS Number: 7440-18-8