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 Number	92
Atomic Weight	238.02891
Mass Number	238

Group
Period	7
Block	f

Protons	92 p⁺
Neutrons	146 n⁰
Electrons	92 e^-

Properties

Energy
Atomic Radius	175 pm 283 pm
Molar Volume	12.5 cm³/mol
Covalent Radius	170 pm 134 pm 118 pm 196 pm
Metallic Radius
Ionic Radius	102.5 pm 89 pm 95 pm 100 pm 105 pm 117 pm 76 pm 84 pm 45 pm 52 pm 73 pm 81 pm 86 pm 118.9 pm
Crystal Radius	116.5 pm 103 pm 109 pm 114 pm 119 pm 131 pm 90 pm 98 pm 59 pm 66 pm 87 pm 95 pm 100 pm 132.9 pm
Van der Waals Radius	230 pm 241 pm 252 pm 339.5 pm
Density	19.1 g/cm³ 17,300 kg/m³
Proton Affinity	995.2 kJ/mol
Electron Affinity
Ionization Energy	6.19405 eV/particle 11.59 eV/particle 19.8 eV/particle 36.7 eV/particle 46 eV/particle 60 eV/particle 89 eV/particle 101 eV/particle 116 eV/particle 129 eV/particle 158 eV/particle 173 eV/particle 210 eV/particle 227 eV/particle 323 eV/particle 348 eV/particle 375 eV/particle 402 eV/particle 431 eV/particle 458 eV/particle 497 eV/particle 525 eV/particle 557 eV/particle 585 eV/particle 730 eV/particle 770 eV/particle 800 eV/particle 840 eV/particle 930 eV/particle 970 eV/particle 1,070 eV/particle 1,110 eV/particle 1,210 eV/particle 1,290 eV/particle 1,360 eV/particle 1,440 eV/particle 1,520 eV/particle 1,590 eV/particle 1,670 eV/particle 1,750 eV/particle 1,830 eV/particle 1,910 eV/particle 1,990 eV/particle 2,070 eV/particle 2,140 eV/particle 2,220 eV/particle 2,578 eV/particle 2,646 eV/particle 2,718 eV/particle 2,794 eV/particle 2,867 eV/particle 2,938 eV/particle 3,073 eV/particle 3,147 eV/particle 3,228 eV/particle 3,301 eV/particle 3,602 eV/particle 3,675 eV/particle 3,753 eV/particle 3,827 eV/particle 4,214 eV/particle 4,299 eV/particle 4,510 eV/particle 4,598 eV/particle 7,393 eV/particle 7,550 eV/particle 7,730 eV/particle 7,910 eV/particle 8,090 eV/particle 8,260 eV/particle 8,650 eV/particle 8,830 eV/particle 9,030 eV/particle 9,210 eV/particle 9,720 eV/particle 9,870 eV/particle 10,040 eV/particle 10,200 eV/particle 11,410 eV/particle 11,600 eV/particle 11,990 eV/particle 12,160 eV/particle 25,260 eV/particle 25,680 eV/particle 26,150 eV/particle 26,590 eV/particle 31,060 eV/particle 31,640 eV/particle 32,400 eV/particle 32,836.5 eV/particle 129,570.3 eV/particle 131,821 eV/particle
Heat of Vaporization	417 kJ/mol
Heat of Fusion	12.6 kJ/mol
Heat of Formation	533 kJ/mol
Electrons
Electron Shells	2, 8, 18, 32, 21, 9, 2
Valence Electrons	6
Electron Configuration	[Rn] 5f³ 6d¹ 7s²
Oxidation States	-1, 1, 2, 3, 4, 5, 6
Electronegativity	0.13207 1.7
Electrophilicity
Phases
Phase	Solid
Gas Phase
Boiling Point	4,404.15 K
Melting Point	1,408.15 K
Critical Pressure
Critical Temperature
Triple Point
Visual
Color	Silver #ff1493 #008fff #008fff
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
Type	Conductor
Electrical Conductivity	3.6 MS/m
Electrical Resistivity	0.00000028 m Ω
Superconducting Point	0.69 K
Magnetism
Type	paramagnetic
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 Structure	Base Centered Orthorhombic (ORC)
Lattice Constant	2.85 Å
Lattice Angles	π/2, π/2, π/2
Mechanical Properties
Hardness	2,400 MPa 6 MPa 1,960 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
Category	Actinides, Actinides
CAS Group
IUPAC Group
Glawe Number	36
Mendeleev Number	20
Pettifor Number	45
Geochemical Class	rare earth & related
Goldschmidt Class	litophile
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 Numbers	5L6
Space Group	63 (Cmcm)

Isotopes of Uranium

Stable Isotopes	3
Unstable Isotopes	26
Radioactive Isotopes	29

²¹⁵U

Abundance	Radioactive ☢️
Relative Atomic Mass	215.026719774 ± 0.000111794 Da
Mass Number	215
G-Factor
Half Life	1.4 ± 0.9 ms
Spin	5/2
Quadrupole Moment
Discovery Year	2015
Parity	-

²¹⁵U Decay Modes

Decay Mode	Intensity
α (α emission)	%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%

²¹⁶U

Abundance	Radioactive ☢️
Relative Atomic Mass	216.024762829 ± 0.000030158 Da
Mass Number	216
G-Factor	0
Half Life	6.9 ± 2.9 ms
Spin	0
Quadrupole Moment	0
Discovery Year	2015
Parity	+

²¹⁶U Decay Modes

Decay Mode	Intensity
α (α emission)	100%

²¹⁷U

Abundance	Radioactive ☢️
Relative Atomic Mass	217.02466 ± 0.000086 Da
Mass Number	217
G-Factor
Half Life	850 ± 710 us
Spin	1/2
Quadrupole Moment	0
Discovery Year	2000
Parity	-

²¹⁷U Decay Modes

Decay Mode	Intensity
α (α emission)	100%
β⁻ (β⁻ decay)	%

²¹⁸U

Abundance	Radioactive ☢️
Relative Atomic Mass	218.023504877 ± 0.000014722 Da
Mass Number	218
G-Factor	0
Half Life	354 ± 91 us
Spin	0
Quadrupole Moment	0
Discovery Year	1992
Parity	+

²¹⁸U Decay Modes

Decay Mode	Intensity
α (α emission)	100%

²¹⁹U

Abundance	Radioactive ☢️
Relative Atomic Mass	219.025009233 ± 0.000014319 Da
Mass Number	219
G-Factor
Half Life	60 ± 7 us
Spin	9/2
Quadrupole Moment
Discovery Year	1993
Parity	+

²¹⁹U Decay Modes

Decay Mode	Intensity
α (α emission)	100%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%

²²⁰U

Abundance	Radioactive ☢️
Relative Atomic Mass	220.024706 ± 0.000108 Da
Mass Number	220
G-Factor	0
Half Life
Spin	0
Quadrupole Moment	0
Discovery Year
Parity	+

²²⁰U Decay Modes

Decay Mode	Intensity
α (α emission)	%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%

²²¹U

Abundance	Radioactive ☢️
Relative Atomic Mass	221.026323297 ± 0.00007744 Da
Mass Number	221
G-Factor
Half Life	660 ± 140 ns
Spin	9/2
Quadrupole Moment
Discovery Year	2015
Parity	+

²²¹U Decay Modes

Decay Mode	Intensity
α (α emission)	100%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%

²²²U

Abundance	Radioactive ☢️
Relative Atomic Mass	222.026057957 ± 0.000055817 Da
Mass Number	222
G-Factor	0
Half Life	4.7 ± 0.7 us
Spin	0
Quadrupole Moment	0
Discovery Year	1983
Parity	+

²²²U Decay Modes

Decay Mode	Intensity
α (α emission)	100%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%

²²³U

Abundance	Radioactive ☢️
Relative Atomic Mass	223.027960754 ± 0.000063396 Da
Mass Number	223
G-Factor
Half Life	65 ± 12 us
Spin	7/2
Quadrupole Moment
Discovery Year	1991
Parity	+

²²³U Decay Modes

Decay Mode	Intensity
α (α emission)	100%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%

²²⁴U

Abundance	Radioactive ☢️
Relative Atomic Mass	224.027635913 ± 0.000016383 Da
Mass Number	224
G-Factor	0
Half Life	396 ± 17 us
Spin	0
Quadrupole Moment	0
Discovery Year	1991
Parity	+

²²⁴U Decay Modes

Decay Mode	Intensity
α (α emission)	100%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%

²²⁵U

Abundance	Radioactive ☢️
Relative Atomic Mass	225.02938505 ± 0.000010664 Da
Mass Number	225
G-Factor
Half Life	62 ± 4 ms
Spin	5/2
Quadrupole Moment
Discovery Year	1989
Parity	+

²²⁵U Decay Modes

Decay Mode	Intensity
α (α emission)	100%

²²⁶U

Abundance	Radioactive ☢️
Relative Atomic Mass	226.029338669 ± 0.000011884 Da
Mass Number	226
G-Factor	0
Half Life	269 ± 6 ms
Spin	0
Quadrupole Moment	0
Discovery Year	1973
Parity	+

²²⁶U Decay Modes

Decay Mode	Intensity
α (α emission)	100%

²²⁷U

Abundance	Radioactive ☢️
Relative Atomic Mass	227.031181124 ± 0.000009136 Da
Mass Number	227
G-Factor
Half Life	1.1 ± 0.1 m
Spin	3/2
Quadrupole Moment
Discovery Year	1952
Parity	+

²²⁷U Decay Modes

Decay Mode	Intensity
α (α emission)	100%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%

²²⁸U

Abundance	Radioactive ☢️
Relative Atomic Mass	228.031368959 ± 0.000014465 Da
Mass Number	228
G-Factor	0
Half Life	9.1 ± 0.2 m
Spin	0
Quadrupole Moment	0
Discovery Year	1949
Parity	+

²²⁸U Decay Modes

Decay Mode	Intensity
α (α emission)	97.5%
ϵ (electron capture)	2.5%

²²⁹U

Abundance	Radioactive ☢️
Relative Atomic Mass	229.033505976 ± 0.000006374 Da
Mass Number	229
G-Factor
Half Life	57.8 ± 0.5 m
Spin	3/2
Quadrupole Moment
Discovery Year	1949
Parity	+

²²⁹U Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	80%
α (α emission)	20%

²³⁰U

Abundance	Radioactive ☢️
Relative Atomic Mass	230.033940114 ± 0.000004841 Da
Mass Number	230
G-Factor	0
Half Life	20.23 ± 0.02 d
Spin	0
Quadrupole Moment	0
Discovery Year	1948
Parity	+

²³⁰U Decay Modes

Decay Mode	Intensity
α (α emission)	100%
22Ne	4.8%
SF (spontaneous fission)	%

²³¹U

Abundance	Radioactive ☢️
Relative Atomic Mass	231.03629218 ± 0.000002866 Da
Mass Number	231
G-Factor
Half Life	4.2 ± 0.1 d
Spin	5/2
Quadrupole Moment
Discovery Year	1949
Parity	+

²³¹U Decay Modes

Decay Mode	Intensity
ϵ (electron capture)	100%
α (α emission)	0.004%

²³²U

Abundance	Radioactive ☢️
Relative Atomic Mass	232.037154765 ± 0.000001941 Da
Mass Number	232
G-Factor	0
Half Life	68.9 ± 0.4 y
Spin	0
Quadrupole Moment	0
Discovery Year	1949
Parity	+

²³²U Decay Modes

Decay Mode	Intensity
α (α emission)	100%
24Ne (heavy cluster emission)	8.9%
SF (spontaneous fission)	2.7%
28Mg	5%

²³³U

Abundance	Radioactive ☢️
Relative Atomic Mass	233.039634294 ± 0.00000242 Da
Mass Number	233
G-Factor	-0.236 ± 0.02
Half Life	159.19 ± 0.15 ky
Spin	5/2
Quadrupole Moment	3.663 ± 0.008
Discovery Year	1947
Parity	+

²³³U Decay Modes

Decay Mode	Intensity
α (α emission)	100%
SF (spontaneous fission)	6%
24Ne (heavy cluster emission)	7.2%
28Mg	1.3%

²³⁴U

Abundance	Radioactive ☢️ 0.0054 ± 0.0005
Relative Atomic Mass	234.040950296 ± 0.000001212 Da
Mass Number	234
G-Factor	0
Half Life	245.5 ± 0.6 ky
Spin	0
Quadrupole Moment	0
Discovery Year	1912
Parity	+

²³⁴U Decay Modes

Decay Mode	Intensity
α (α emission)	100%
SF (spontaneous fission)	1.64%
28Mg	1.4%
26Ne	9%

²³⁵U

Abundance	Radioactive ☢️ 0.7204 ± 0.0006
Relative Atomic Mass	235.043928117 ± 0.000001198 Da
Mass Number	235
G-Factor	-0.10857142857143 ± 0.0085714285714286
Half Life	704 ± 1 My
Spin	7/2
Quadrupole Moment	4.936 ± 0.006
Discovery Year	1935
Parity	-

²³⁵U Decay Modes

Decay Mode	Intensity
α (α emission)	100%
SF (spontaneous fission)	7%
20Ne	8%
25Ne	8%
28Mg	8%

²³⁶U

Abundance	Radioactive ☢️
Relative Atomic Mass	236.04556613 ± 0.000001193 Da
Mass Number	236
G-Factor	0
Half Life	23.42 ± 0.04 My
Spin	0
Quadrupole Moment	0
Discovery Year	1951
Parity	+

²³⁶U Decay Modes

Decay Mode	Intensity
α (α emission)	100%
SF (spontaneous fission)	9.4%

²³⁷U

Abundance	Radioactive ☢️
Relative Atomic Mass	237.048728309 ± 0.00000129 Da
Mass Number	237
G-Factor
Half Life	6.752 ± 0.002 d
Spin	1/2
Quadrupole Moment	0
Discovery Year	1940
Parity	+

²³⁷U Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

²³⁸U

Abundance	Radioactive ☢️ 99.2742 ± 0.001
Relative Atomic Mass	238.050786936 ± 0.000001601 Da
Mass Number	238
G-Factor	0
Half Life	4.463 ± 0.003 Gy
Spin	0
Quadrupole Moment	0
Discovery Year	1896
Parity	+

²³⁸U Decay Modes

Decay Mode	Intensity
α (α emission)	100%
SF (spontaneous fission)	5.44%
2β⁻ (double β⁻ decay)	2.2%

²³⁹U

Abundance	Radioactive ☢️
Relative Atomic Mass	239.054291989 ± 0.000001612 Da
Mass Number	239
G-Factor
Half Life	23.45 ± 0.02 m
Spin	5/2
Quadrupole Moment
Discovery Year	1937
Parity	+

²³⁹U Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

²⁴⁰U

Abundance	Radioactive ☢️
Relative Atomic Mass	240.056592411 ± 0.00000274 Da
Mass Number	240
G-Factor	0
Half Life	14.1 ± 0.1 h
Spin	0
Quadrupole Moment	0
Discovery Year	1953
Parity	+

²⁴⁰U Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
α (α emission)	%

²⁴¹U

Abundance	Radioactive ☢️
Relative Atomic Mass	241.06033 ± 0.00021 Da
Mass Number	241
G-Factor
Half Life
Spin	7/2
Quadrupole Moment
Discovery Year
Parity	+

²⁴¹U Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	%

²⁴²U

Abundance	Radioactive ☢️
Relative Atomic Mass	242.062931 ± 0.000215 Da
Mass Number	242
G-Factor	0
Half Life	16.8 ± 0.5 m
Spin	0
Quadrupole Moment	0
Discovery Year	1979
Parity	+

²⁴²U Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

²⁴³U

Abundance	Radioactive ☢️
Relative Atomic Mass	243.067075 ± 0.000322 Da
Mass Number	243
G-Factor
Half Life
Spin	9/2
Quadrupole Moment
Discovery Year
Parity	-

²⁴³U Decay Modes

Decay Mode	Intensity
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

Discoverers	Martin Klaproth
Discovery Location	Germany
Discovery Year	1789
Etymology (Name Origin)	Named for the planet Uranus.
Pronunciation	yoo-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

Uranium on ChemicalAid

AGROVOC ID	c_8084
ASC Leiden Thesaurus ID	294942866
Art & Architecture Thesaurus ID	300011035
Australian Educational Vocabulary ID	scot/3596
BNCF Thesaurus ID	28092
Bibliothèque nationale de France ID	119337333
CAB ID	7541
CA PROP 65 ID	uranium
CAS Registry Number	7440-61-1
ChEBI ID	49936
ChemSpider ID	22425
Common Procurement Vocabulary	09341000
DSSTOX compound identifier	DTXCID304373
DSSTox substance ID	DTXSID1042522
DeCS ID	29600
Den Store Danske ID	uran
ECHA Substance Infocard ID	100.028.336
Encyclopædia Britannica Online ID	science/uranium
Encyclopædia Universalis ID	uranium
EuroVoc ID	4617
Freebase ID	/m/025smjn
French Vikidia ID	Uranium
GND ID	4187153-4
Giant Bomb ID	3055-1158
Gran Enciclopèdia Catalana ID	0239849
Great Russian Encyclopedia Online ID	4700723
HCIS ID	4695
HSDB ID	2553
InChI	InChI=1S/U
InChIKey	JFALSRSLKYAFGM-UHFFFAOYSA-N
KBpedia ID	Uranium
LEM ID	LEM201013089
Library of Congress authority ID	sh85141276
MeSH descriptor ID	D014501
NE.se ID	uran
NKCR AUT ID	ph126944
Namuwiki ID	우라늄
National Diet Library ID	00574039
National Library of Israel J9U ID	987007529652205171
OmegaWiki Defined Meaning	3902
OpenAlex ID	C555451288
PDB ligand ID	U1
PDB structure ID	1B0H
PDB structure ID	1B05
PDB structure ID	1B7H
PDB structure ID	1UYJ
PDB structure ID	1B5J
PDB structure ID	1B5H
PDB structure ID	1B5I
PDB structure ID	1B3H
PDB structure ID	3DGC
PDB structure ID	1B6H
PDB structure ID	1B4H
PDB structure ID	1B2H
PSH ID	5771
PubChem CID	23989
Quora topic ID	Uranium
RxNorm ID	10999
Römpp online ID	RD-21-00662
STW Thesaurus for Economics ID	14222-5
Store medisinske leksikon ID	uran
Store norske leksikon ID	uran
Treccani ID	uranio
U.S. National Archives Identifier	10644103
UK Archival Thesaurus ID	f2/mt225/4347/6506
UK Parliament thesaurus ID	13549
UNESCO Thesaurus ID	concept14026
UNII	4OC371KSTK
WordNet 3.1 Synset ID	14684622-n
YSO ID	11691
ZVG number	7920

Uranium (U)

Properties

Isotopes of Uranium

215U

215U Decay Modes

216U

216U Decay Modes

217U

217U Decay Modes

218U

218U Decay Modes

219U

219U Decay Modes

220U

220U Decay Modes

221U

221U Decay Modes

222U

222U Decay Modes

223U

223U Decay Modes

224U

224U Decay Modes

225U

225U Decay Modes

226U

226U Decay Modes

227U

227U Decay Modes

228U

228U Decay Modes

229U

229U Decay Modes

230U

230U Decay Modes

231U

231U Decay Modes

232U

232U Decay Modes

233U

233U Decay Modes

234U

234U Decay Modes

235U

235U Decay Modes

236U

236U Decay Modes

237U

237U Decay Modes

238U

238U Decay Modes

239U

239U Decay Modes

240U

240U Decay Modes

241U

241U Decay Modes

242U

242U Decay Modes

243U

243U Decay Modes