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.
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