Uranium

Uranium (U)

White radioactive metallic element belonging to the actinoids. Three natural isotopes, U-238, U-235 and U-234. Uranium-235 is used as the fuel for nuclear reactors and weapons. Discovered by Martin H. Klaproth in 1789.
Atomic Number92
Atomic Weight238.02891
Mass Number238
Group
Period7
Blockf
Protons92 p+
Neutrons146 n0
Electrons92 e-
Uranium2.jpg Animated Bohr Model of U (Uranium) Enhanced Bohr Model of U (Uranium) Bohr Model: U (Uranium) Orbital Diagram of U (Uranium)

Properties

Atomic Radius
175 pm
Molar Volume
Covalent Radius
170 pm
Metallic Radius
Ionic Radius
102.5 pm
Crystal Radius
116.5 pm
Van der Waals Radius
241 pm
Density
19.1 g/cm³
Energy
Proton Affinity
995.2 kJ/mol
Electron Affinity
Ionization Energy
6.19405 eV/particle
Heat of Vaporization
417 kJ/mol
Heat of Fusion
12.6 kJ/mol
Heat of Formation
533 kJ/mol
Electrons
Electron Shells2, 8, 18, 32, 21, 9, 2
Valence Electrons6
Electron Configuration[Rn] 5f3 6d1 7s2
Oxidation States-1, 1, 2, 3, 4, 5, 6
Electronegativity
1.7
Electrophilicity
Phases
PhaseSolid
Gas Phase
Boiling Point
4,404.15 K
Melting Point
1,408.15 K
Critical Pressure
Critical Temperature
Triple Point
Visual
Color
Silver
Appearance
Refractive Index
Thermodynamic Properties
Thermal Conductivity
27.5 W/(m K)
Thermal Expansion
0.0000139 1/K
Molar Heat Capacity
27.665 J/(mol K)
Specific Heat Capacity
0.116 J/(g⋅K)
Heat Capacity Ratio (Adiabatic Index)
Electrical Properties
TypeConductor
Electrical Conductivity
3.6 MS/m
Electrical Resistivity
0.00000028 m Ω
Superconducting Point
0.69 K
Magnetism
Typeparamagnetic
Magnetic Susceptibility (Mass)
0.0000000216 m³/Kg
Magnetic Susceptibility (Molar)
0.00000000514 m³/mol
Magnetic Susceptibility (Volume)
0.000411
Magnetic Ordering
Curie Point
Neel Point
Structure
Crystal StructureBase Centered Orthorhombic (ORC)
Lattice Constant
2.85 Å
Lattice Anglesπ/2, π/2, π/2
Mechanical Properties
Hardness
6 MPa
Bulk Modulus
100 GPa
Shear Modulus
111 GPa
Young Modulus
208 GPa
Poisson Ratio
0.23
Speed of Sound
3,155 m/s
Classification
CategoryActinides, Actinides
CAS Group
IUPAC Group
Glawe Number36
Mendeleev Number20
Pettifor Number45
Geochemical Classrare earth & related
Goldschmidt Classlitophile
Other
Gas Basicity
973.2 kJ/mol
Dipole Polarizability
129 ± 17 a₀
C6 Dispersion Coefficient
Allotropes
Neutron Cross Section
7.57
Neutron Mass Absorption
0.0005
Quantum Numbers5L6
Space Group63 (Cmcm)

Isotopes of Uranium

Stable Isotopes3
Unstable Isotopes26
Radioactive Isotopes29

215U

AbundanceRadioactive ☢️
Relative Atomic Mass
215.026719774 ± 0.000111794 Da
Mass Number215
G-Factor
Half Life
1.4 ± 0.9 ms
Spin5/2
Quadrupole Moment
Discovery Year2015
Parity-

215U Decay Modes
Decay ModeIntensity
α (α emission)%
β+ (β+ decay; β+ = ϵ + e+)%

216U

AbundanceRadioactive ☢️
Relative Atomic Mass
216.024762829 ± 0.000030158 Da
Mass Number216
G-Factor
0
Half Life
6.9 ± 2.9 ms
Spin0
Quadrupole Moment
0
Discovery Year2015
Parity+

216U Decay Modes
Decay ModeIntensity
α (α emission)100%

217U

AbundanceRadioactive ☢️
Relative Atomic Mass
217.02466 ± 0.000086 Da
Mass Number217
G-Factor
Half Life
850 ± 710 us
Spin1/2
Quadrupole Moment
0
Discovery Year2000
Parity-

217U Decay Modes
Decay ModeIntensity
α (α emission)100%
β (β decay)%

218U

AbundanceRadioactive ☢️
Relative Atomic Mass
218.023504877 ± 0.000014722 Da
Mass Number218
G-Factor
0
Half Life
354 ± 91 us
Spin0
Quadrupole Moment
0
Discovery Year1992
Parity+

218U Decay Modes
Decay ModeIntensity
α (α emission)100%

219U

AbundanceRadioactive ☢️
Relative Atomic Mass
219.025009233 ± 0.000014319 Da
Mass Number219
G-Factor
Half Life
60 ± 7 us
Spin9/2
Quadrupole Moment
Discovery Year1993
Parity+

219U Decay Modes
Decay ModeIntensity
α (α emission)100%
β+ (β+ decay; β+ = ϵ + e+)%

220U

AbundanceRadioactive ☢️
Relative Atomic Mass
220.024706 ± 0.000108 Da
Mass Number220
G-Factor
0
Half Life
Spin0
Quadrupole Moment
0
Discovery Year
Parity+

220U Decay Modes
Decay ModeIntensity
α (α emission)%
β+ (β+ decay; β+ = ϵ + e+)%

221U

AbundanceRadioactive ☢️
Relative Atomic Mass
221.026323297 ± 0.00007744 Da
Mass Number221
G-Factor
Half Life
660 ± 140 ns
Spin9/2
Quadrupole Moment
Discovery Year2015
Parity+

221U Decay Modes
Decay ModeIntensity
α (α emission)100%
β+ (β+ decay; β+ = ϵ + e+)%

222U

AbundanceRadioactive ☢️
Relative Atomic Mass
222.026057957 ± 0.000055817 Da
Mass Number222
G-Factor
0
Half Life
4.7 ± 0.7 us
Spin0
Quadrupole Moment
0
Discovery Year1983
Parity+

222U Decay Modes
Decay ModeIntensity
α (α emission)100%
β+ (β+ decay; β+ = ϵ + e+)%

223U

AbundanceRadioactive ☢️
Relative Atomic Mass
223.027960754 ± 0.000063396 Da
Mass Number223
G-Factor
Half Life
65 ± 12 us
Spin7/2
Quadrupole Moment
Discovery Year1991
Parity+

223U Decay Modes
Decay ModeIntensity
α (α emission)100%
β+ (β+ decay; β+ = ϵ + e+)%

224U

AbundanceRadioactive ☢️
Relative Atomic Mass
224.027635913 ± 0.000016383 Da
Mass Number224
G-Factor
0
Half Life
396 ± 17 us
Spin0
Quadrupole Moment
0
Discovery Year1991
Parity+

224U Decay Modes
Decay ModeIntensity
α (α emission)100%
β+ (β+ decay; β+ = ϵ + e+)%

225U

AbundanceRadioactive ☢️
Relative Atomic Mass
225.02938505 ± 0.000010664 Da
Mass Number225
G-Factor
Half Life
62 ± 4 ms
Spin5/2
Quadrupole Moment
Discovery Year1989
Parity+

225U Decay Modes
Decay ModeIntensity
α (α emission)100%

226U

AbundanceRadioactive ☢️
Relative Atomic Mass
226.029338669 ± 0.000011884 Da
Mass Number226
G-Factor
0
Half Life
269 ± 6 ms
Spin0
Quadrupole Moment
0
Discovery Year1973
Parity+

226U Decay Modes
Decay ModeIntensity
α (α emission)100%

227U

AbundanceRadioactive ☢️
Relative Atomic Mass
227.031181124 ± 0.000009136 Da
Mass Number227
G-Factor
Half Life
1.1 ± 0.1 m
Spin3/2
Quadrupole Moment
Discovery Year1952
Parity+

227U Decay Modes
Decay ModeIntensity
α (α emission)100%
β+ (β+ decay; β+ = ϵ + e+)%

228U

AbundanceRadioactive ☢️
Relative Atomic Mass
228.031368959 ± 0.000014465 Da
Mass Number228
G-Factor
0
Half Life
9.1 ± 0.2 m
Spin0
Quadrupole Moment
0
Discovery Year1949
Parity+

228U Decay Modes
Decay ModeIntensity
α (α emission)97.5%
ϵ (electron capture)2.5%

229U

AbundanceRadioactive ☢️
Relative Atomic Mass
229.033505976 ± 0.000006374 Da
Mass Number229
G-Factor
Half Life
57.8 ± 0.5 m
Spin3/2
Quadrupole Moment
Discovery Year1949
Parity+

229U Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)80%
α (α emission)20%

230U

AbundanceRadioactive ☢️
Relative Atomic Mass
230.033940114 ± 0.000004841 Da
Mass Number230
G-Factor
0
Half Life
20.23 ± 0.02 d
Spin0
Quadrupole Moment
0
Discovery Year1948
Parity+

230U Decay Modes
Decay ModeIntensity
α (α emission)100%
22Ne4.8%
SF (spontaneous fission)%

231U

AbundanceRadioactive ☢️
Relative Atomic Mass
231.03629218 ± 0.000002866 Da
Mass Number231
G-Factor
Half Life
4.2 ± 0.1 d
Spin5/2
Quadrupole Moment
Discovery Year1949
Parity+

231U Decay Modes
Decay ModeIntensity
ϵ (electron capture)100%
α (α emission)0.004%

232U

AbundanceRadioactive ☢️
Relative Atomic Mass
232.037154765 ± 0.000001941 Da
Mass Number232
G-Factor
0
Half Life
68.9 ± 0.4 y
Spin0
Quadrupole Moment
0
Discovery Year1949
Parity+

232U Decay Modes
Decay ModeIntensity
α (α emission)100%
24Ne (heavy cluster emission)8.9%
SF (spontaneous fission)2.7%
28Mg5%

233U

AbundanceRadioactive ☢️
Relative Atomic Mass
233.039634294 ± 0.00000242 Da
Mass Number233
G-Factor
-0.236 ± 0.02
Half Life
159.19 ± 0.15 ky
Spin5/2
Quadrupole Moment
3.663 ± 0.008
Discovery Year1947
Parity+

233U Decay Modes
Decay ModeIntensity
α (α emission)100%
SF (spontaneous fission)6%
24Ne (heavy cluster emission)7.2%
28Mg1.3%

234U

AbundanceRadioactive ☢️
0.0054 ± 0.0005
Relative Atomic Mass
234.040950296 ± 0.000001212 Da
Mass Number234
G-Factor
0
Half Life
245.5 ± 0.6 ky
Spin0
Quadrupole Moment
0
Discovery Year1912
Parity+

234U Decay Modes
Decay ModeIntensity
α (α emission)100%
SF (spontaneous fission)1.64%
28Mg1.4%
26Ne9%

235U

AbundanceRadioactive ☢️
0.7204 ± 0.0006
Relative Atomic Mass
235.043928117 ± 0.000001198 Da
Mass Number235
G-Factor
-0.10857142857143 ± 0.0085714285714286
Half Life
704 ± 1 My
Spin7/2
Quadrupole Moment
4.936 ± 0.006
Discovery Year1935
Parity-

235U Decay Modes
Decay ModeIntensity
α (α emission)100%
SF (spontaneous fission)7%
20Ne8%
25Ne8%
28Mg8%

236U

AbundanceRadioactive ☢️
Relative Atomic Mass
236.04556613 ± 0.000001193 Da
Mass Number236
G-Factor
0
Half Life
23.42 ± 0.04 My
Spin0
Quadrupole Moment
0
Discovery Year1951
Parity+

236U Decay Modes
Decay ModeIntensity
α (α emission)100%
SF (spontaneous fission)9.4%

237U

AbundanceRadioactive ☢️
Relative Atomic Mass
237.048728309 ± 0.00000129 Da
Mass Number237
G-Factor
Half Life
6.752 ± 0.002 d
Spin1/2
Quadrupole Moment
0
Discovery Year1940
Parity+

237U Decay Modes
Decay ModeIntensity
β (β decay)100%

238U

AbundanceRadioactive ☢️
99.2742 ± 0.001
Relative Atomic Mass
238.050786936 ± 0.000001601 Da
Mass Number238
G-Factor
0
Half Life
4.463 ± 0.003 Gy
Spin0
Quadrupole Moment
0
Discovery Year1896
Parity+

238U Decay Modes
Decay ModeIntensity
α (α emission)100%
SF (spontaneous fission)5.44%
(double β decay)2.2%

239U

AbundanceRadioactive ☢️
Relative Atomic Mass
239.054291989 ± 0.000001612 Da
Mass Number239
G-Factor
Half Life
23.45 ± 0.02 m
Spin5/2
Quadrupole Moment
Discovery Year1937
Parity+

239U Decay Modes
Decay ModeIntensity
β (β decay)100%

240U

AbundanceRadioactive ☢️
Relative Atomic Mass
240.056592411 ± 0.00000274 Da
Mass Number240
G-Factor
0
Half Life
14.1 ± 0.1 h
Spin0
Quadrupole Moment
0
Discovery Year1953
Parity+

240U Decay Modes
Decay ModeIntensity
β (β decay)100%
α (α emission)%

241U

AbundanceRadioactive ☢️
Relative Atomic Mass
241.06033 ± 0.00021 Da
Mass Number241
G-Factor
Half Life
Spin7/2
Quadrupole Moment
Discovery Year
Parity+

241U Decay Modes
Decay ModeIntensity
β (β decay)%

242U

AbundanceRadioactive ☢️
Relative Atomic Mass
242.062931 ± 0.000215 Da
Mass Number242
G-Factor
0
Half Life
16.8 ± 0.5 m
Spin0
Quadrupole Moment
0
Discovery Year1979
Parity+

242U Decay Modes
Decay ModeIntensity
β (β decay)100%

243U

AbundanceRadioactive ☢️
Relative Atomic Mass
243.067075 ± 0.000322 Da
Mass Number243
G-Factor
Half Life
Spin9/2
Quadrupole Moment
Discovery Year
Parity-

243U Decay Modes
Decay ModeIntensity
β (β decay)%

History

Uranium was discovered in 1789 by the German chemist Martin Heinrich Klaproth. In 1841, Eugène-Melchior Péligot isolated the first sample of uranium metal by heating uranium tetrachloride with potassium. Antoine Henri Becquerel discovered radioactivity by using uranium in 1896. Named after the planet Uranus

DiscoverersMartin Klaproth
Discovery LocationGermany
Discovery Year1789
Etymology (Name Origin)Named for the planet Uranus.
Pronunciationyoo-RAY-ni-em (English)
Uranium is toxic and highly radioactive
Uranium-235 was the first isotope that was found to be fissile

Uses

Uranium is used as fuel for nuclear power plants. Uranium is used as a colorant in uranium glass, producing orange-red to lemon yellow hues. It was also used for tinting and shading in early photography. The major application of uranium in the military sector is in high-density penetrators. For many centuries it was used as a pigment for glass. Now it is used as a fuel in nuclear reactors and in bombs.

Sources

Occurs in many rocks, but in large amounts only in such minerals as pitchblende and carnotite.

Abundance
Abundance in Earth's crust
2.7 mg/kg
Abundance in Oceans
0.0032 mg/L
Abundance in Human Body
0.0000001 %
Abundance in Meteor
0.00000098 %
Abundance in Sun
0.0000001 %
Abundance in Universe
0.00000002 %

Nuclear Screening Constants