Gadolinium
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.
Gallery
Jurii, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons, source: https://images-of-elements.com/gadolinium.php
Physical Propertiesmass · density · phase · crystal
Atomic Mass
157.2500Da
Density
7.9000g/cm³
Phase (STP)
Solid
Melting Point
1586.2K
Boiling Point
3546.2K
Molar Heat
0.2360J/(mol·K)
Crystal Structure
HEX
Lattice Constant
3.640Å
Atomic Radiiatomic · covalent · van der Waals
Atomic (Empirical)
180.00pm
Covalent
169.00pm
Van der Waals
234.00pm
Electronic Propertieselectronegativity · ionization · affinity
Electron Configuration
[Xe] 4f7 5d 6s2
Electron Shells
2, 8, 18, 25, 9, 2
Electronegativity
1.20Pauling
Electron Affinity
—
1st Ionization Energy
6.1kJ/mol
Oxidation States
+1, +2, +3
Orbital DiagramAufbau · Hund's rule · Pauli exclusion
Full: 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f7 5d1 6s2Short: [Xe] 4f7 5d 6s2
Ionization Energies (64 known)
Emission Spectrumvisible range · characteristic spectral lines
Abundanceby mass
Log scale · ppm = parts per million by mass
Biological Role
No known biological role. Gadolinium compounds used as MRI contrast agents.
Discovery
Discovered By
Jean de Marignac
Named By
—
Year
1880
Nuclear Data
Known Isotopes
40
Stable Isotopes
6
Stable Mass Numbers
154, 155, 156, 157, 158, 160
Natural isotopic abundance (IUPAC recommended values)
Isotopes of Gd40 known
| Nuclide | Z | N | Mass (AMU) | Half-life | Decay | Jπ | Abundance |
|---|---|---|---|---|---|---|---|
| 133Gd | 64 | 69 | 132.961288 | Unknown | β⁺, β⁺p | 5/2+ | — |
| 134Gd | 64 | 70 | 133.955416 | Unknown | β⁺, β⁺p | 0+ | — |
| 135Gd | 64 | 71 | 134.952496 | 1.10 s | β⁺ (1%), β⁺p (0.02%) | 5/2+ | — |
| 152Gd | 64 | 88 | 151.919798 | 108000 Gy | α (1%), 2β⁺ | 0+ | 20.0000% |
| 154Gdstable | 64 | 90 | 153.920873 | Stable | stable (1%) | 0+ | 218.0000% |
| 155Gdstable | 64 | 91 | 154.922629 | Stable | stable (1%) | 3/2- | 1480.0000% |
| 156Gdstable | 64 | 92 | 155.922130 | Stable | stable (1%) | 0+ | 2047.0000% |
| 157Gdstable | 64 | 93 | 156.923967 | Stable | stable (1%) | 3/2- | 1565.0000% |
| 158Gdstable | 64 | 94 | 157.924111 | Stable | stable (1%) | 0+ | 2484.0000% |
| 160Gdstable | 64 | 96 | 159.927061 | Stable | 2β⁻ | 0+ | 2186.0000% |
| 170Gd | 64 | 106 | 169.956146 | 420 ms | β⁻ (1%), β⁻n | 0+ | — |
| 171Gd | 64 | 107 | 170.961127 | Unknown | β⁻, β⁻n | 9/2+ | — |
| 172Gd | 64 | 108 | 171.964605 | Unknown | β⁻, β⁻n | 0+ | — |