Chemicool

U

92

238.029
Uranium
General | States | Energies | Oxidation & Electrons |Appearance & Characteristics
Reactions | Other Forms |Radius | Conductivity | Abundance
Encyclopedia Britannica articles

General
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

States
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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Energies
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

Reactions
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

Radius
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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Conductivity
thermal conductivity 27.5 J/m-sec-deg electrical conductivity 33.333 1/mohm-cm
polarizability 27.4 A^3

Abundance
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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