Uranium, 92 U Uranium Pronunciation (yoor-AY -nee-əm ) Appearance silvery gray metallic; corrodes to a spalling black oxide coat in air Standard atomic weight A r, std (U) 238.02891 (3)[1] Uranium in the periodic table
Atomic number (Z ) 92 Group group n/a Period period 7 Block f-block Element category f-block Electron configuration [Rn ] 5f3 6d1 7s2 Electrons per shell 2, 8, 18, 32, 21, 9, 2 Physical properties Phase at STP solid Melting point 1405.3 K (1132.2 °C, 2070 °F) Boiling point 4404 K (4131 °C, 7468 °F) Density (near r.t. ) 19.1 g/cm3 when liquid (at m.p. ) 17.3 g/cm3 Heat of fusion 9.14 kJ/mol Heat of vaporization 417.1 kJ/mol Molar heat capacity 27.665 J/(mol·K) Vapor pressure
P (Pa)
1
10
100
1 k
10 k
100 k
at T (K)
2325
2564
2859
3234
3727
4402
Atomic properties Oxidation states +1, +2, +3,[2] +4 , +5, +6 (an amphoteric oxide) Electronegativity Pauling scale: 1.38 Ionization energies 1st: 597.6 kJ/mol 2nd: 1420 kJ/mol Atomic radius empirical: 156 pm Covalent radius 196±7 pm Van der Waals radius 186 pm Spectral lines of uraniumOther properties Natural occurrence primordial Crystal structure orthorhombic Speed of sound thin rod 3155 m/s (at 20 °C) Thermal expansion 13.9 µm/(m·K) (at 25 °C) Thermal conductivity 27.5 W/(m·K) Electrical resistivity 0.280 µΩ·m (at 0 °C) Magnetic ordering paramagnetic Young's modulus 208 GPa Shear modulus 111 GPa Bulk modulus 100 GPa Poisson ratio 0.23 Vickers hardness 1960–2500 MPa Brinell hardness 2350–3850 MPa CAS Number 7440-61-1 History Naming after planet Uranus , itself named after Greek god of the sky Uranus Discovery Martin Heinrich Klaproth (1789) First isolation Eugène-Melchior Péligot (1841) Main isotopes of uranium
Category: Uranium view · talk · edit
| references
U
data m.p. cat
C
1132.2
—
—
K
1405.3
1405.3
0
F
2070
2070.0
0
max precision
1
WD
input
C: 1132.2, K: 1405.3, F: 2070
comment
U
data b.p. cat
C
4131
—
—
K
4404
4404
0
F
7468
7468
0
max precision
0
WD
input
C: 4131, K: 4404, F: 7468
comment
References
These references will appear in the article, but this list appears only on this page.
↑ Meija, Juris; Coplen, Tyler B.; Berglund, Michael; Brand, Willi A.; De Bièvre, Paul; Gröning, Manfred; Holden, Norman E.; Irrgeher, Johanna et al . (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry 88 (3): 265–91. doi :10.1515/pac-2015-0305 .
↑ The Chemistry of the Actinide and Transactinide Elements (3rd ed.). Netherlands: Springer. 2006. ISBN 978-9048131464 .
Template:Documentation