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 Enhanced Bohr Model Bohr Model Orbital Diagram

Properties

Atomic Radius
175 pm
Atomic Volume
Covalent Radius
170 pm
Metallic Radius
Ionic Radius
102.49999999999999 pm
Crystal Radius
116.5 pm
Van der Waals radius
241 pm
Density
19.1 g/cm³
Boiling Point
4,018 K
Melting Point
1,405.5 K
Electrons per shell2, 8, 18, 32, 21, 9, 2
Electronegativity
1.7
Electrophilicity
Proton Affinity
995.2 kJ/mol
Electron Affinity
Ionization Potential
6.19405 eV/particle
Heat of Vaporization
417 kJ/mol
Heat of Fusion
12.6 kJ/mol
Heat of Formation
533 kJ/mol
Molar Heat Capacity
27.665 J/(mol K)
Specific Heat Capacity
0.116 J/(g⋅K)
Thermal Conductivity
27.5 W/(m K)
Gas Basicity
973.2 kJ/mol
Dipole Polarizability
129 a₀
C6 Dispersion Coefficient
Oxidation States3, 4, 5, 6
Color
Silver
Crystal StructureBase Centered Orthorhombic (ORC)
Lattice Constant
2.85 Å
Bulk Modulus
Electrical Resistivity
Electron Configuration[Rn] 5f3 6d1 7s2
Magnetic Ordering
Magnetic Susceptibility
PhaseSolid
Poisson Ratio
Shear Modulus
Young's Modulus
Allotropes
Alternate Names
Adiabatic Index
Appearance
Electric Conductivity
Critical Pressure
Critical Temperature
Curie Point
Electrical
Hardness
Magnetic Susceptibility
Magnetic
Neel Point
Neutron Cross Section
Neutron Mass Absorption
Gas Phase
Quantum Numbers
Refractive Index
Space Group
Speed of Sound
Superconducting Point
Thermal Expansion
Valence Electrons
Classification
CategoryActinides, Actinides
CAS Group
IUPAC Group
Glawe Number36
Mendeleev Number20
Pettifor Number45
Geochemical Classrare earth & related
Goldschmidt Classlitophile
Radioactivity
RadioactiveYes ☢️
Decay Mode
Half-Life
Lifetime
Abundance
Abundance in Earth's crust
2.7 mg/kg
Abundance in Oceans
0.0032 mg/L
Abundance in Human Body
Abundance in Meteor
Abundance in Sun
Abundance in Universe2×10-8%

Isotopes of Uranium

Stable Isotopes
234U 235U 238U
Unstable Isotopes
217U 218U 219U 220U 221U 222U 223U 224U 225U 226U 227U 228U 229U 230U 231U 232U 233U 236U 237U 239U 240U 241U 242U

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
Name OriginNamed for the planet Uranus.
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.