General | States | Energies | Oxidation & Electrons |Appearance & Characteristics
Reactions | Other Forms |Radius | Conductivity | Abundance
Encyclopedia Britannica articles


Name Ruthenium Symbol Ru
atomic number 44 Atomic weight 101.07
Density @ 293 K 12.2 g/cm3 Atomic volume 8.3 cm3/mol
Group Trans. Met. discovered 1844


state (s, l, g) s
melting point 2583.2 K boiling point 4323 K
Heat of fusion 24.0 kJ/mol Heat of vaporization 595.0 kJ/mol
Back to the top


1st ionization energy 711.1 kJ/mole electronegativity 2.2
2nd ionization energy 1617.1 kJ/mole electron affinity 101 kJ/mole
3rd ionization energy 2746.9 kJ/mole Specific heat 0.238 J/gK
heat atomization 643 kJ/mole atoms

Oxidation & Electrons

Shells 2,8,18,15,1 electron configuration [Kr] 4d7 5s1
minimum oxidation number -2 maximum oxidation number 8
min. common oxidation no. 0 max. common oxidation no. 4
Back to the top

Appearance & Characteristics

structure hcp: hexagonal close pkd color silvery-white
uses catalysts toxicity
hardness 6.5 mohs characteristics hard


reaction with air none below 800 deg.C reaction with 6M HCl none
reaction with 6M HCl none reaction with 15M HNO3 none
reaction with 6M NaOH
Back to the top

Other Forms

number of isotopes 7 hydride(s) none
oxide(s) RuO2 RuO4 chloride(s) RuCl2 RuCl3


ionic radius (2- ion) pm ionic radius (1- ion) pm
atomic radius 134 pm ionic radius (1+ ion) pm
ionic radius (2+ ion) pm ionic radius (3+ ion) 82 pm
Back to the top


thermal conductivity 117 J/m-sec-deg electrical conductivity 131.579 1/mohm-cm
polarizability 9.6 A^3


source nickel ores (sulfides) rel. abund. solar system 0.270 log
abundance earth's crust -3 log cost, pure 1400 $/100g
cost, bulk $/100g
Back to the top

World Wide Web presentation of Chemicool Periodic Table is © Copyright 1996-99 by David D. Hsu. Some data were provided by and used with the permission of JCE Software and is owned and copyright by the Division of Chemical Education, Inc. Additional data were provided by Perkin-Elmer through Peter Lykos of IIT. The information may not be redistributed without the permission of David Hsu or JCE Software.