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


Name Rhodium Symbol Rh
atomic number 45 Atomic weight 102.9055
Density @ 293 K 12.4 g/cm3 Atomic volume 8.3 cm3/mol
Group Trans. Met. discovered 1803


state (s, l, g) s
melting point 2238.2 K boiling point 4033 K
Heat of fusion 21.50 kJ/mol Heat of vaporization 493.0 kJ/mol
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1st ionization energy 719.8 kJ/mole electronegativity 2.28
2nd ionization energy 1744.4 kJ/mole electron affinity 109.7 kJ/mole
3rd ionization energy 2996.8 kJ/mole Specific heat 0.242 J/gK
heat atomization 556 kJ/mole atoms

Oxidation & Electrons

Shells 2,8,18,16,1 electron configuration [Kr] 4d8 5s1
minimum oxidation number -1 maximum oxidation number 6
min. common oxidation no. 0 max. common oxidation no. 3
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Appearance & Characteristics

structure fcc: face-centered cubic color silvery-white
uses catalysts, elec. contacts toxicity
hardness mohs characteristics forms hard coatings


reaction with air none, w/ht = Rh2O3 reaction with 6M HCl none
reaction with 6M HCl none reaction with 15M HNO3 none
reaction with 6M NaOH none
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Other Forms

number of isotopes 1 hydride(s) none
oxide(s) Rh2O3 RhO2 chloride(s) RhCl3


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) 80.5 pm
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thermal conductivity 150 J/m-sec-deg electrical conductivity 221.729 1/mohm-cm
polarizability 8.6 A^3


source nickel ores (sulfides) rel. abund. solar system -0.463 log
abundance earth's crust -3 log cost, pure 13000 $/100g
cost, bulk $/100g
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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.