Template:Infobox technetium

Technetium,  43Tc
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General properties
PronunciationTemplate:Infobox element/pronunciation
Appearanceshiny gray metal
Standard atomic weight (Ar, standard)Template:Infobox element/standard atomic weight
Mass numberTemplate:Infobox element/symbol-to-most-stable-isotope (most stable isotope)
Technetium in the periodic table
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Atomic number (Z)43
GroupTemplate:Infobox element/group
Periodperiod 5
Blockd-block
Element categoryTemplate:Infobox element/category format
Electron configuration[Kr] 4d5 5s2
Electrons per shell
2, 8, 18, 13, 2
Physical properties
Phase at STPsolid
Melting point2430 K ​(2157 °C, ​3915 °F)
Boiling point4538 K ​(4265 °C, ​7709 °F)
Density (near r.t.)11 g/cm3
Heat of fusion33.29 kJ/mol
[[Enthalpy of vaporization|Heat of Template:Engvar]]585.2 kJ/mol
Molar heat capacity24.27 J/(mol·K)
[[Vapor pressure|Template:Engvar pressure]] (extrapolated)
Atomic properties
Oxidation statesTemplate:Infobox element/symbol-to-oxidation-state
ElectronegativityPauling scale: 1.9
[[Ionization energy|Template:Engvar energies]]
  • 1st: 702 kJ/mol
  • 2nd: 1470 kJ/mol
  • 3rd: 2850 kJ/mol
Atomic radiusempirical: 136 pm
Covalent radius147±7 pm
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Other properties
Crystal structureTemplate:Infobox element/crystal structure
Speed of sound thin rod16,200 m/s (at 20 °C)
Thermal expansion7.1 µm/(m·K)[1] (at r.t.)
Thermal conductivity50.6 W/(m·K)
Electrical resistivity200 nΩ·m (at 20 °C)
Magnetic orderingParamagnetic
Magnetic susceptibility+270.0·10−6 cm3/mol (298 K)[2]
CAS Number7440-26-8
History
PredictionDmitri Mendeleev (1871)
Discovery and first isolationEmilio Segrè and Carlo Perrier (1937)
Main isotopes of technetium
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| references

Template:Infobox element/element navigation Template:Template reference list Expression error: Unrecognized word "template".

  1. Cverna, Fran (2002). "Ch. 2 Thermal Expansion". ASM Ready Reference: Thermal properties of metals (PDF). ASM International. ISBN 978-0-87170-768-0.
  2. Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.
  3. 3.0 3.1 "Technetium: technetium(III) iodide compound data". OpenMOPAC.net. Retrieved 2007-12-10.