Terbium

Frae Wikipedia
Lowp tae: navigation, rake
Terbium
65Tb
-

Tb

Bk
gadoliniumterbiumdysprosium
Appearance
silvery white
General properties
Name, seembol, nummer terbium, Tb, 65
Pronunciation /ˈtɜrbiəm/ TUR-bee-əm
Element category lanthanide
Group, period, block n/a, 6, f
Staundart atomic wicht 158.92535
Electron confeeguration [Xe] 4f9 6s2
2, 8, 18, 27, 8, 2
Electron shells of terbium (2, 8, 18, 27, 8, 2)
History
Namin after Ytterby (Swaden), whaur it wis mined
Discovery Carl Gustaf Mosander (1842)
First isolation Carl Gustaf Mosander (1842)
Physical properties
Phase solid
Density (near r.t.) 8.23 g·cm−3
Liquid density at m.p. 7.65 g·cm−3
Meltin pynt 1629 K, 1356 °C, 2473 °F
Boilin pynt 3503 K, 3230 °C, 5846 °F
Heat o fusion 10.15 kJ·mol−1
Heat o vaporization 293 kJ·mol−1
Molar heat capacity 28.91 J·mol−1·K−1
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1789 1979 (2201) (2505) (2913) (3491)
Atomic properties
Oxidation states 4, 3, 2, 1
(weakly basic oxide)
Electronegativity  ? 1.2 (Pauling scale)
Ionization energies 1st: 565.8 kJ·mol−1
2nd: 1110 kJ·mol−1
3rd: 2114 kJ·mol−1
Atomic radius 177 pm
Covalent radius 194±5 pm
Miscellanea
Crystal structure hexagonal close-packed
Terbium has a hexagonal close packed crystal structure
Magnetic orderin paramagnetic at 300 K
Electrical resistivity (r.t.) (α, poly) 1.150 µΩ·m
Thermal conductivity 11.1 W·m−1·K−1
Thermal expansion (r.t.) (α, poly) 10.3 µm/(m·K)
Speed of sound (thin rod) (20 °C) 2620 m·s−1
Young's modulus (α form) 55.7 GPa
Shear modulus (α form) 22.1 GPa
Bulk modulus (α form) 38.7 GPa
Poisson ratio (α form) 0.261
Vickers hairdness 863 MPa
Brinell hairdness 677 MPa
CAS registry nummer 7440-27-9
Most stable isotopes
Main article: Isotopes o terbium
iso NA hauf-life DM DE (MeV) DP
157Tb syn 71 y ε 0.060 157Gd
158Tb syn 180 y ε 1.220 158Gd
β 0.937 158Dy
159Tb 100% - (SF) <74.878
Decay modes in parentheses are predictit, but hae nae yet been observed
· r

Terbium is a chemical element wi the seembol Tb an atomic nummer 65. It is a sillery-white rare yird metal that is malleable, ductile an saft enough tae be cut wi a knife. Terbium is never foond in naitur as a free element, but it is contained in mony minerals, includin cerite, gadolinite, monazite, xenotime an euxenite.

References[eedit | eedit soorce]