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


Name Uranium Symbol U
atomic number 92 Atomic weight 238.029
Density @ 293 K 18.9 g/cm3 Atomic volume 12.59 cm3/mol
Group Rare Earth, Actinides discovered 1789


state (s, l, g) s
melting point 1405.2 K boiling point 4203 K
Heat of fusion 8.520 kJ/mol Heat of vaporization 477.0 kJ/mol
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1st ionization energy 584 kJ/mole electronegativity 1.7
2nd ionization energy kJ/mole electron affinity kJ/mole
3rd ionization energy kJ/mole Specific heat 0.12 J/gK
heat atomization 490 kJ/mole atoms

Oxidation & Electrons

Shells 2,8,18,32,21,9,2 electron configuration [Rn] 5f3 6d1 7s2
minimum oxidation number 0 maximum oxidation number 6
min. common oxidation no. 0 max. common oxidation no. 6
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Appearance & Characteristics

structure hcp:hex cls pkd distorted color silvery
uses nuclear reactor fuel toxicity
hardness mohs characteristics Radioactive


reaction with air mild, = U3O8 reaction with 6M HCl mild, = H2
reaction with 6M HCl mild, = H2 reaction with 15M HNO3 passivated
reaction with 6M NaOH none
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Other Forms

number of isotopes 3 hydride(s) UH3
oxide(s) UO UO2 U2O5 U3O8 UO3 chloride(s) UCl3 UCl4 UCl5 UCl6


ionic radius (2- ion) pm ionic radius (1- ion) pm
atomic radius 156 pm ionic radius (1+ ion) pm
ionic radius (2+ ion) pm ionic radius (3+ ion) 116.5 pm
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thermal conductivity 27.5 J/m-sec-deg electrical conductivity 33.333 1/mohm-cm
polarizability 27.4 A^3


source Uranite (oxide) rel. abund. solar system -2.046 log
abundance earth's crust 0.4 log cost, pure $/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.