Chemical element with atomic number 44 (Ru)
Ruthenium, 44 Ru Pronunciation (roo-THEE -nee-əm ) Appearance silvery white metallic
Atomic number (Z ) 44 Group group 8 Period period 5 Block d-block Electron configuration [Kr ] 4d7 5s1 Electrons per shell 2, 8, 18, 15, 1 Phase at STP solid Melting point 2607 K (2334 °C, 4233 °F) Boiling point 4423 K (4150 °C, 7502 °F) Density (at 20° C) 12.364 g/cm3 [ 3] 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) Vapor pressure
P (Pa)
1
10
100
1 k
10 k
100 k
at T (K)
2588
2811
3087
3424
3845
4388
Oxidation states −4, −2, 0, +1,[citation needed ] +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 Spectral lines of rutheniumNatural occurrence primordial Crystal structure hexagonal close-packed (hcp) (hP2 ) Lattice constants a = 270.58 pmc = 428.16 pm (at 20 °C)[ 3] Thermal expansion 6.78× 10−6 /K (at 20 °C)[ 3] [ a] Thermal conductivity 117
αa 5.77
αc 8.80
αavr 6.78 W/(m⋅K) Electrical resistivity 71 nΩ⋅m (at 0 °C) Magnetic ordering paramagnetic [ 4] Molar magnetic susceptibility +39× 10−6 cm3 /mol (298 K)[ 4] Young's modulus 447 GPa Shear modulus 173 GPa Bulk modulus 220 GPa Speed of sound thin rod 5970 m/s (at 20 °C) Poisson ratio 0.30 Mohs hardness 6.5 Brinell hardness 2160 MPa CAS Number 7440-18-8 Naming after Ruthenia , the 19th-century Latin name for Russia [ b] Discovery and first isolationKarl Ernst Claus (1844)
Category: Ruthenium | references
child table, as reused in {IB-Ru}
^ "Standard Atomic Weights: Ruthenium" . CIAAW . 1983.
^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)" . Pure and Applied Chemistry . doi :10.1515/pac-2019-0603 . ISSN 1365-3075 .
^ a b c d Arblaster, John W. (2018). Selected Values of the Crystallographic Properties of Elements . Materials Park, Ohio: ASM International. ISBN 978-1-62708-155-9 .
^ a b Haynes, p. 4.130
^ Matthey, Johnson. "The Discovery of Ruthenium" . Johnson Matthey Technology Review . Retrieved 2020-08-25 .
^ Pitchkov, V. N. (1996). "The Discovery of Ruthenium" . Platinum Metals Review . 40 (4): 181–188.
^ a b Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF) . Chinese Physics C . 45 (3): 030001. doi :10.1088/1674-1137/abddae .
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