Gadolinium

Gadolinium (Gd)

Soft silvery metallic element belonging to the lanthanoids. Seven natural, stable isotopes are known in addition to eleven artificial isotopes. Gd-155 and Gd-157 and the best neutron absorbers of all elements. Gadolinium compounds are used in electronics. Discovered by J.C.G Marignac in 1880.
Atomic Number64
Atomic Weight157.25
Mass Number158
Group
Period6
Blockf
Protons64 p+
Neutrons94 n0
Electrons64 e-
Gadolinium.jpg Animated Bohr Model Enhanced Bohr Model Bohr Model Orbital Diagram

Properties

Atomic Radius
180 pm
Atomic Volume
Covalent Radius
169 pm
Metallic Radius
Ionic Radius
93.8 pm
Crystal Radius
107.80000000000001 pm
Van der Waals radius
234 pm
Density
7.9 g/cm³
Boiling Point
3,539 K
Melting Point
1,586 K
Electrons per shell2, 8, 18, 25, 9, 2
Electronegativity
1.2
Electrophilicity
Proton Affinity
Electron Affinity
Ionization Potential
6.149796 eV/particle
Heat of Vaporization
398 kJ/mol
Heat of Fusion
Heat of Formation
397.5 kJ/mol
Molar Heat Capacity
37.03 J/(mol K)
Specific Heat Capacity
0.236 J/(g⋅K)
Thermal Conductivity
Gas Basicity
Dipole Polarizability
158 a₀
C6 Dispersion Coefficient
Oxidation States1, 2, 3
Color
Silver
Crystal StructureSimple Hexagonal (HEX)
Lattice Constant
3.64 Å
Bulk Modulus
Electrical Resistivity
Electron Configuration[Xe] 4f7 5d1 6s2
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
CategoryLanthanides, Lanthanides
CAS Group
IUPAC Group
Glawe Number26
Mendeleev Number27
Pettifor Number27
Geochemical Classrare earth & related
Goldschmidt Classlitophile
Radioactivity
RadioactiveNo
Decay Mode
Half-Life
Lifetime
Abundance
Abundance in Earth's crust
6.2 mg/kg
Abundance in Oceans
0.0000007 mg/L
Abundance in Human Body
Abundance in Meteor
Abundance in Sun
Abundance in Universe2×10-7%

Isotopes of Gadolinium

Stable Isotopes
152Gd 154Gd 155Gd 156Gd 157Gd 158Gd 160Gd
Unstable Isotopes
134Gd 135Gd 136Gd 137Gd 138Gd 139Gd 140Gd 141Gd 142Gd 143Gd 144Gd 145Gd 146Gd 147Gd 148Gd 149Gd 150Gd 151Gd 153Gd 159Gd 161Gd 162Gd 163Gd 164Gd 165Gd 166Gd 167Gd 168Gd 169Gd

History

Gadolinium was first detected spectroscopically in 1880 by the Swiss chemist Jean Charles Galissard de Marignac who separated its oxide. He observed spectroscopic lines due to gadolinium in samples of gadolinite and in the separate mineral cerite. The metal was isolated by Paul Emile Lecoq de Boisbaudran in 1886. From gadolinite, a mineral named for Gadolin, a Finnish chemist

DiscoverersJean de Marignac
Discovery LocationSwitzerland
Discovery Year1880
Name OriginNamed after the mineral gadolinite.
Gadolinium is considered to be moderately toxic
Gadolinium has the highest neutron cross-section among any stable nuclides

Uses

Gadolinium is used to make gadolinium yttrium garnets which have microwave applications. It is also used in intravenous radiocontrast agents in magnetic resonance imaging (MRI). Gadolinium compounds are used for making green phosphors for color TV tubes, and in manufacturing compact discs. Used in steel alloying agents and the manufacture of electronic components.

Sources

Found with other rare earths in gadolinite and monazite sand.