Technetium

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Technetium,  43Tc
General properties
Mass nummer 98 (most stable isotope)
Technetium 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 Gold 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
Mn

Tc

Re
molybdenumtechnetiumruthenium
Atomic nummer (Z) 43
Group group 7
Period period 5
Element category   transition metal
Block d-block
Electron confeeguration [Kr] 4d5 5s2
Electrons per shell
2, 8, 18, 13, 2
Pheesical properties
Phase (at STP) solit
Meltin pynt 2430 K ​(2157 °C, ​3915 °F)
Bylin pynt 4538 K ​(4265 °C, ​7709 °F)
Density (near r.t.) 11 g/cm3
Heat o fusion 33.29 kJ/mol
Heat o vapourisation 585.2 kJ/mol
Molar heat capacity 24.27 J/(mol·K)
Vapour pressur (extrapolatit)
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 2727 2998 3324 3726 4234 4894
Atomic properties
Oxidation states 7, 6, 5, 4, 3[1], 2, 1[2], -1, -3 ​strangly acidic oxide
Electronegativity Pauling scale: 1.9
Atomic radius empirical: 136 pm
Covalent radius 147±7 pm
Color lines in a spectral range
Miscellanea
Creestal structur hexagonal close-packed (hcp)
Hexagonal close packed creestal structur for technetium
Speed o soond thin rod 16,200 m/s (at 20 °C)
Thermal conductivity 50.6 W/(m·K)
Magnetic orderin Paramagnetic
CAS Nummer 7440-26-8
History
Predeection Dmitri Mendeleev (1871)
Diskivery Carlo Perrier an Emilio Segrè (1937)
First isolation Carlo Perrier an Emilio Segrè (1937)
Main isotopes o technetium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
95mTc syn 61 d ε - 95Mo
γ 0.204, 0.582,
0.835
-
IT 0.0389, e 95Tc
96Tc syn 4.3 d ε - 96Mo
γ 0.778, 0.849,
0.812
-
97Tc syn 2.6×106 y ε 97Mo
97mTc syn 91 d IT 97Tc
98Tc syn 4.2×106 y β 0.4 98Ru
γ 0.745, 0.652 -
99Tc trace 2.111×105 y β 99Ru
99mTc syn 6.01 h IT 0.142, 0.002 99Tc
γ 0.140 -
| references | in Wikidata

Technetium is the chemical element wi atomic number 43 an seembol Tc. It is the lawest atomic number element wioot ony stable isotopes; every fairm o it is radioactive. Nearly aw technetium is produced synthetically, an anly minute amoonts are foond in naitur. Naiturally occurrin technetium occurs as a spontaneous fission product in uranium ore or bi neutron capture in molybdenum ores. The chemical properties o this sillery gray, crystalline transeetion metal are intermediate atween rhenium an manganese.

Mony o technetium's properties wur predictit bi Dmitri Mendeleev afore the element wis discovered. Mendeleev notit a gap in his periodic table an gae the undiscovered element the provisional name ekamanganese (Em). In 1937, technetium (specifically the technetium-97 isotope) acame the first predominantly airtificial element tae be produced, hence its name (frae the Greek τεχνητός, meanin "airtificial").

Its short-lived gamma ray-emitting nuclear isomertechnetium-99m—is uised in nuclear medicine for a wide variety o diagnostic tests. Technetium-99 is uised as a gamma ray-free soorce o beta pairticles. Lang-lived technetium isotopes produced commercially are bi-products o fission o uranium-235 in nuclear reactors an are extractit frae nuclear fuel rods. Acause na isotope o technetium haes a hauf-life langer than 4.2 million years (technetium-98), its detection in 1952 in red giants, which are billions o years auld, helped bolster the theory that starns can produce hivier elements.

References[eedit | eedit soorce]

  1. "Technetium: technetium(III) iodide compound data". OpenMOPAC.net. Retrieved 2007-12-10. 
  2. "Technetium: technetium(I) fluoride compound data". OpenMOPAC.net. Retrieved 2007-12-10.