Gadolinium

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Gadolinium
64Gd
-

Gd

Cm
europiumgadoliniumterbium
Appearance
sillery white
General properties
Name, seembol, nummer gadolinium, Gd, 64
Pronunciation /ˌɡædəˈlɪniəm/
GAD-ə-LIN-ee-əm
Element category lanthanide
Group, period, block n/a, 6, f
Staundart atomic wicht 157.25
Electron confeeguration [Xe] 4f7 5d1 6s2
2, 8, 18, 25, 9, 2
Electron shells of gadolinium (2, 8, 18, 25, 9, 2)
History
Namin efter the mineral Gadolinite (itself named efter Johan Gadolin)
Discovery Jean Charles Galissard de Marignac (1880)
First isolation Lecoq de Boisbaudran (1886)
Physical properties
Phase solid
Density (near r.t.) 7.90 g·cm−3
Liquid density at m.p. 7.4 g·cm−3
Meltin pynt 1585 K, 1312 °C, 2394 °F
Boilin pynt 3546 K, 3273 °C, 5923 °F
Heat o fusion 10.05 kJ·mol−1
Heat o vaporization 301.3 kJ·mol−1
Molar heat capacity 37.03 J·mol−1·K−1
Vapor pressure (calculated)
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1836 2028 2267 2573 2976 3535
Atomic properties
Oxidation states 1, 2, 3 (mildly basic oxide)
Electronegativity 1.20 (Pauling scale)
Ionization energies 1st: 593.4 kJ·mol−1
2nd: 1170 kJ·mol−1
3rd: 1990 kJ·mol−1
Atomic radius 180 pm
Covalent radius 196±6 pm
Miscellanea
Crystal structure hexagonal close-packed
Gadolinium has a hexagonal close packed crystal structure
Magnetic orderin ferromagnetic/paramagnetic
transeetion at 293.4 K
Electrical resistivity (r.t.) (α, poly) 1.310 µΩ·m
Thermal conductivity 10.6 W·m−1·K−1
Thermal expansion (100 °C, α, poly) 9.4 µm/(m·K)
Speed of sound (thin rod) (20 °C) 2680 m·s−1
Young's modulus (α form) 54.8 GPa
Shear modulus (α form) 21.8 GPa
Bulk modulus (α form) 37.9 GPa
Poisson ratio (α form) 0.259
Vickers hairdness 570 MPa
CAS registry nummer 7440-54-2
Most stable isotopes
Main article: Isotopes o gadolinium
iso NA hauf-life DM DE (MeV) DP
152Gd 0.20% 1.08×1014 y α 2.205 148Sm
154Gd 2.18% - (α) 0.0812 150Sm
155Gd 14.80% - (α) 0.0812 151Sm
156Gd 20.47% - (SF) <71.541
157Gd 15.65% - (SF) <70.531
158Gd 24.84% - (SF) <70.965
160Gd 21.86% >1.3×1021 y (ββ) 1.729 160Dy
Decay modes in parentheses are predictit, but hae nae yet been observed
· r

Gadolinium is a chemical element wi seembol Gd a atomic nummer 64. It is a sillery-white, malleable an ductile rare-yird metal. It is foond in naitur anly in combined (saut) furm. Gadolinium wis first detectit spectroscopically in 1880 bi de Marignac who separatit its oxide and is creditit wi its discovery. It is named for gadolinite, ane o the minerals in which it was foond, in turn named for chemist Johan Gadolin. The metal wis isolatit bi Paul Emile Lecoq de Boisbaudran in 1886.

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