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The mineralogy of Technetium

About Technetium
Technetium is the lightest element with no stable isotopes and is found in vanishingly small quantities in nature (as a natural byproduct of uranium fission - with an estimated 1 nanogram per kilogram of uranium). It has also been detected in the spectra of some red giant stars - the discovery of this in 1952 was the first unambiguous proof of nucleosynthesis in stars.
General Properties
Atomic Number:43
Standard atomic weight (Ar):[98]
Electron configuration:[Kr] 4d5 5s2
Technetium metal
Atomic Properties
Electronegativity (Pauling scale):1.9
Atomic Radius:183 pm
Ionic Radius:64.5 pm (+4)
1st Ionization energy:702 kJ/mol
1st Electron affinity:-53 kJ/mol
Oxidation States:-3,-1,1,2,3,4,5,6,7
Physical Properties
Standard State:solid
Bonding Type:metallic
Melting Point:2430 K
Boiling Point:4538 K
Density:11.5 g/cm3
Metal/Non-Metal:transition metal
Main isotopes of Technetium
Isotope% in NatureHalf LifeDecay typeDecay product
Isomeric transition95Tc
97mTcsynthetic91dIsomeric transition97Tc
99mTcsynthetic6.01hIsomeric transition99Tc
Other Information
Year Discovered:1937
Discovered By:
Emilio Segrè
Carlo Perrier

Emilio Segrè and Carlo Perrier
Year Predicted:1871
Year Isolated:1937
Isolated By:Emilio Segrè and Carlo Perrier
Named For:Greek: technetos - "artificial"
CPK color coding:#3B9E9E
External Links:WikipediaWebElementsLos Alamos National LaboratoryTheodore Gray's
Simple Compounds
Sulfidestechnetium disulphideTcS2+4
Fluoridestechnetium hexafluorideTcF6+6
technetium pentafluorideTcF5+5
Chloridestechnetium hexachlorideTcCl6+6
technetium tetrachlorideTcCl4+4
Bromidestechnetium tetrabromideTcBr4+4
Oxidestechnetium dioxideTcO2+4
ditechnetium heptoxideTc2O7+7
Geochemistry of Technetium
Goldschmidt classification:Lithophile
Periodic Table
1H 2He
3Li 4Be 5B 6C 7N 8O 9F 10Ne
11Na 12Mg 13Al 14Si 15P 16S 17Cl 18Ar
19K 20Ca 21Sc 22Ti 23V 24Cr 25Mn 26Fe 27Co 28Ni 29Cu 30Zn 31Ga 32Ge 33As 34Se 35Br 36Kr
37Rb 38Sr 39Y 40Zr 41Nb 42Mo 43Tc 44Ru 45Rh 46Pd 47Ag 48Cd 49In 50Sn 51Sb 52Te 53I 54Xe
55Cs 56Ba 57La 72Hf 73Ta 74W 75Re 76Os 77Ir 78Pt 79Au 80Hg 81Tl 82Pb 83Bi 84Po 85At 86Rn
87Fr 88Ra 89Ac 104Rd 105Db 106Sg 107Bh 108Hs 109Mt 110Ds 111Rg 112Cn 113Nh 114Fl 115Mc 116Lv 117Ts 118Og
58Ce 59Pr 60Nd 61Pm 62Sm 63Eu 64Gd 65Tb 66Dy 67Ho 68Er 69Tm 70Yb 71Lu
90Th 91Pa 92U 93Np 94Pu 95Am 96Cm 97Bk 98Cf 99Es 100Fm 101Md 102No 103Lr
Default Categories CPK Electronegativity Atomic Radius Lowest Oxidation Highest Oxidation Crustal Abundance Goldschmidt Mineral Species
Molybdenum << Technetium >> Ruthenium

Spotted a mistake/omission? - These pages are a work in progress, so please send all comments/corrections to Thank you.

Constants and physical property data from:

David R. Lide (ed.), CRC Handbook of Chemistry and Physics, 85th Edition. CRC Press. Boca Raton, Florida (2005).
Kaye and Laby Tables of Physical & Chemical Constants (2005). Section 3.1.3, Abundances of the elements
A. Earnshaw, N. Greenwood, Chemistry of the Elements, 2nd edition, Butterworth-Heinemann, (1997)
Thomas J. Ahrens (ed.), Global Earth Physics : A Handbook of Physical Constants, American Geophysical Union (1995)
L.B. Railsback, An Earth Scientist's Periodic Table of the Elements and Their Ions : Geology 31:9 p737-740 (2003)
Emsley, J. Nature's Building Blocks: An A-Z Guide to the Elements. New York: Oxford University Press (2001)
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