Gadolinium
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| General properties | |||||
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| Name, symbol | Gadolinium, Gd | ||||
| Appearance | Silvery white | ||||
| Gadolinium in the periodic table | |||||
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| Atomic number | 64 | ||||
| Standard atomic weight (Ar) | 157.25(3) | ||||
| Group, block | , f-block | ||||
| Period | period 6 | ||||
| Electron configuration | [Xe] 4f7 5d1 6s2 | ||||
per shell | 2, 8, 18, 25, 9, 2 | ||||
| Physical properties | |||||
| Silvery-white | |||||
| Phase | Solid | ||||
| Melting point | 1585 K (1312 °C, 2394 °F) | ||||
| Boiling point | 3273 K (3000 °C, 5432 °F) | ||||
| Density near r.t. | 7.90 g/cm3 | ||||
| when liquid, at | 7.4 g/cm3 | ||||
| Heat of fusion | 10.05 kJ/mol | ||||
| Heat of | 301.3 kJ/mol | ||||
| Molar heat capacity | 37.03 J/(mol·K) | ||||
| pressure | |||||
| Atomic properties | |||||
| Oxidation states | 1, 2, 3 (a mildly basic oxide) | ||||
| Electronegativity | Pauling scale: 1.20 | ||||
| energies |
1st: 593.4 kJ/mol 2nd: 1170 kJ/mol 3rd: 1990 kJ/mol | ||||
| Atomic radius | empirical: 180 pm | ||||
| Covalent radius | 196±6 pm | ||||
| Miscellanea | |||||
| Crystal structure | Hexagonal close-packed (hcp) | ||||
| Speed of sound thin rod | 2680 m/s (at 20 °C) | ||||
| Thermal expansion | 9.4 µm/(m·K) (α poly, at 100 °C) | ||||
| Thermal conductivity | 10.6 W/(m·K) | ||||
| Electrical resistivity | 1.31·10-6 Ω·m (α, poly) | ||||
| Magnetic ordering | Ferromagnetic-paramagnetic transition at 293.4 K | ||||
| Young's modulus | 54.8 GPa (α, poly) | ||||
| Shear modulus | 21.8 GPa (α, poly) | ||||
| Bulk modulus | 37.9 GPa (α, poly) | ||||
| Poisson ratio | 0.259 | ||||
| Vickers hardness | 510–950 MPa | ||||
| CAS Registry Number | 7440-54-2 | ||||
| History | |||||
| Naming | After the mineral Gadolinite (itself named after Johan Gadolin) | ||||
| Discovery | Jean Charles Galissard de Marignac (1880) | ||||
| First isolation | Lecoq de Boisbaudran (1886) | ||||
Gadolinium is a lanthanide with the symbol Gd and atomic number 64.
Contents
Properties
Chemical
Gadolinium, like all of the lanthanides, is quite electropositive. It dissolves in acids, weak and strong, without hesitation.
Physical
Gadolinium is a silvery white metal. At room temperature and above, it is strongly paramagnetic, but below that temperature, it is ferromagnetic.
Availability
Gadolinium metal can be bought from Metallium.
Preparation
It is possible to produce gadolinium through thermite with lithium metal or electrolysis of anhydrous gadolinium chloride, but this is impractical. Considering the low availability of gadolinium compounds in general, it is more feasible to simply buy the metal.
Projects
- Make Gd compounds
- Demonstrate the Curie point
Handling
Safety
Like all of the lanthanides, not much research has gone into their toxicity, though they are all believed to be minimally toxic. Due to the lack of knowledge, care should be taken with gadolinium compounds and gloves should be worn. Gadolinium metal itself poses little health hazard and can be handled by hand safely without the risk of poisoning or damaging the sample.
Storage
Gadolinium should be kept in closed bottles away from moisture and any corrosive vapors.
Disposal
Best to try to recycle it.
References
Relevant Sciencemadness threads
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