Thulium is a chemical element that haes the seembol Tm an atomic nummer 69. It is the thirteent an antepenultimate element in the lanthanide series. Lik the ither lanthanides, the maist common oxidation state is +3, seen in its oxide, halides an ither compoonds. In aqueous solution, lik compoonds o ither late lanthanides, soluble thulium compoonds furm complexes wi nine watter molecules.

Thulium, 69Tm
Template:Infobox element/symbol-to-top-image/alt
Thulium
Pronunciation/ˈθjliəm/ (THEW-lee-əm)
Appearancesilvery gray
Standard atomic weight Ar, std(Tm)168.934218(6)[1]
Thulium 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
-

Tm

Md
erbiumthuliumytterbium
Atomic nummer (Z)69
Groupgroup n/a
Periodperiod 6
Blockf-block
Element category  Lanthanide
Electron confeeguration[Xe] 4f13 6s2
Electrons per shell2, 8, 18, 31, 8, 2
Pheesical properties
Phase at STPsolit
Meltin pynt1818 K ​(1545 °C, ​2813 °F)
Bylin pynt2223 K ​(1950 °C, ​3542 °F)
Density (near r.t.)9.32 g/cm3
when liquid (at m.p.)8.56 g/cm3
Heat o fusion16.84 kJ/mol
Heat o vapourisation247 kJ/mol
Molar heat capacity27.03 J/(mol·K)
Vapour pressur
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1117 1235 1381 1570 (1821) (2217)
Atomic properties
Oxidation states+2, +3 (a basic oxide)
ElectronegativityPauling scale: 1.25
Atomic radiusempirical: 176 pm
Covalent radius190±10 pm
Colour lines in a spectral range
Spectral lines o thulium
Ither properties
Naitural occurrenceprimordial
Creestal structurhexagonal close-packed (hcp)
Hexagonal close packed creestal structur for thulium
Thermal expansion(r.t.) (poly)
13.3 µm/(m·K)
Thermal conductivity16.9 W/(m·K)
Electrical resistivity(r.t.) (poly) 676 n Ω·m
Magnetic orderinparamagnetic at 300 K
Young's modulus74.0 GPa
Shear modulus30.5 GPa
Bulk modulus44.5 GPa
Poisson ratio0.213
Vickers haurdness520 MPa
Brinell haurdness471 MPa
CAS Nummer7440-30-4
History
DiskiveryPer Teodor Cleve (1879)
First isolationPer Teodor Cleve (1879)
Main isotopes o thulium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
167Tm syn 9.25 d ε 167Er
168Tm syn 93.1 d ε 168Er
169Tm 100% - (α) 165Ho
170Tm syn 128.6 d β 170Yb
171Tm syn 1.92 y β 171Yb
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.