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.

Terbium, 65Tb
Template:Infobox element/symbol-to-top-image/alt
Terbium
Pronunciation/ˈtɜːrbiəm/ (TUR-bee-əm)
Appearancesilvery white
Standard atomic weight Ar, std(Tb)158.925354(8)[1]
Terbium in the periodic cairt
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Airn Cobalt Nickel Capper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Siller (element) Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gowd Mercur (element) Thallium Leid (element) Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Ununtrium Flerovium Ununpentium Livermorium Ununseptium Ununoctium
-

Tb

Bk
gadoliniumterbiumdysprosium
Atomic nummer (Z)65
Groupgroup n/a
Periodperiod 6
Blockf-block
Element category  Lanthanide
Electron confeeguration[Xe] 4f9 6s2
Electrons per shell2, 8, 18, 27, 8, 2
Pheesical properties
Phase at STPsolit
Meltin pynt1629 K ​(1356 °C, ​2473 °F)
Bylin pynt3503 K ​(3230 °C, ​5846 °F)
Density (near r.t.)8.23 g/cm3
when liquid (at m.p.)7.65 g/cm3
Heat o fusion10.15 kJ/mol
Heat o vapourisation293 kJ/mol
Molar heat capacity28.91 J/(mol·K)
Vapour pressur
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1789 1979 (2201) (2505) (2913) (3491)
Atomic properties
Oxidation states0,[2] +1, +2, +3, +4 waikly basic
ElectronegativityPauling scale: ? 1.2
Atomic radiusempirical: 177 pm
Covalent radius194±5 pm
Colour lines in a spectral range
Spectral lines o terbium
Ither properties
Naitural occurrenceprimordial
Creestal structurhexagonal close-packed (hcp)
Hexagonal close packed creestal structur for terbium
Speed o soond thin rod2620 m/s (at 20 °C)
Thermal expansion(r.t.) (α, poly) 10.3 µm/(m·K)
Thermal conductivity11.1 W/(m·K)
Electrical resistivity(r.t.) (α, poly) 1.150 µ Ω·m
Magnetic orderinparamagnetic at 300 K
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 haurdness863 MPa
Brinell haurdness677 MPa
CAS Nummer7440-27-9
History
DiskiveryCarl Gustaf Mosander (1842)
First isolationCarl Gustaf Mosander (1842)
Main isotopes o terbium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
157Tb syn 71 y ε 157Gd
158Tb syn 180 y ε 158Gd
β 158Dy
159Tb 100% - (SF)
Decay modes in parentheses are predictit, but hae nae yet been observed
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ReferencesEedit

  1. Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.
  2. Yttrium and all lanthanides except Ce, Pm, Eu, Tm, Yb have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see Cloke, F. Geoffrey N. (1993). "Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides". Chem. Soc. Rev. 22: 17–24. doi:10.1039/CS9932200017.