Tellurium is a chemical element wi seembol Te an atomic nummer 52. A brickle, mildly toxic, rare, siller-white metalloid that looks seemilar tae tin, tellurium is chemically relatit tae selenium an sulphur. It is occasionally foond in native furm, as elemental crystals. Tellurium is far mair common in the universe as a hale nor it is on Yird. Its extreme rarity in the Yird's crust, comparable tae that o platinum, is pairtly due tae its heich atomic nummer, but it's forbye due tae its furmation o a volatile hydride that caused the element tae be lost tae space as a gas in the het nebular formation o the planet.

Tellurium, 52Te
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Tellurium
Pronunciation/tɪˈljʊəriəm/ (tih-LEWR-ee-əm)
Appearancesillery lustrous gray
Standard atomic weight Ar, std(Te)127.60(3)[1]
Mass numberTe:
Tellurium 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
Se

Te

Po
antimonytelluriumiodine
Atomic nummer (Z)52
Groupgroup 16 (chalcogens)
Periodperiod 5
Blockp-block
Element category  Metalloid
Electron confeeguration[Kr] 4d10 5s2 5p4
Electrons per shell2, 8, 18, 18, 6
Pheesical properties
Phase at STPsolit
Meltin pynt722.66 K ​(449.51 °C, ​841.12 °F)
Bylin pynt1261 K ​(988 °C, ​1810 °F)
Density (near r.t.)6.24 g/cm3
when liquid (at m.p.)5.70 g/cm3
Heat o fusion17.49 kJ/mol
Heat o vapourisation114.1 kJ/mol
Molar heat capacity25.73 J/(mol·K)
Vapour pressur
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K)     (775) (888) 1042 1266
Atomic properties
Oxidation states−2, −1, +1, +2, +3, +4, +5, +6 (a mildly acidic oxide)
ElectronegativityPauling scale: 2.1
Atomic radiusempirical: 140 pm
Covalent radius138±4 pm
Van der Waals radius206 pm
Colour lines in a spectral range
Spectral lines o tellurium
Ither properties
Naitural occurrenceTe: Primordial
Creestal structurhexagonal[2]
Hexagonal creestal structur for tellurium
Speed o soond thin rod2610 m/s (at 20 °C)
Thermal conductivity(1.97–3.38) W/(m·K)
Magnetic orderindiamagnetic[3]
Young's modulus43 GPa
Shear modulus16 GPa
Bulk modulus65 GPa
Mohs haurdness2.25
Brinell haurdness180 MPa
CAS Nummer13494-80-9
History
DiskiveryFranz-Joseph Müller von Reichenstein (1782)
First isolationMartin Heinrich Klaproth
Main isotopes o tellurium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
120Te 0.09% >2.2×1016 y (β+β+) 120Sn
121Te syn 16.78 d ε 121Sb
122Te 2.55% - (SF)
123Te 0.89% >5×1019 y (ε) 123Sb
124Te 4.74% - (SF)
125Te 7.07% - (SF)
126Te 18.84% - (SF)
127Te syn 9.35 h β 127I
128Te 31.74% 2.2×1024 y ββ 128Xe
129Te syn 69.6 min β 129I
130Te 34.08% 7.9×1020 y ββ 130Xe
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. Cite uses deprecated parameter |displayauthors= (help)
  2. Tellurium, mindat.org
  3. Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics 81st edition, CRC press.