General | States | Energies | Oxidation & Electrons |Appearance & Characteristics
Reactions | Other Forms |Radius | Conductivity | Abundance
Encyclopedia Britannica articles


Name Technetium Symbol Tc
atomic number 43 Atomic weight 98.9062
Density @ 293 K 11.5 g/cm3 Atomic volume 8.5 cm3/mol
Group Trans. Met. discovered 1939


state (s, l, g) s
melting point 2445.2 K boiling point 4840 K
Heat of fusion 24.0 kJ/mol Heat of vaporization 660.0 kJ/mol
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1st ionization energy 702.4 kJ/mole electronegativity 1.9
2nd ionization energy 1472.4 kJ/mole electron affinity 53 kJ/mole
3rd ionization energy 2850.2 kJ/mole Specific heat 0.21 J/gK
heat atomization 677 kJ/mole atoms

Oxidation & Electrons

Shells 2,8,18,14,1 electron configuration [Kr] 4d5 5s2
minimum oxidation number -3 maximum oxidation number 7
min. common oxidation no. 0 max. common oxidation no. 7
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Appearance & Characteristics

structure hcp: hexagonal close pkd color silvery gray
uses medical imaging agents toxicity
hardness mohs characteristics Radioactive, man made


reaction with air mild, w/ht, = Tc2O7 reaction with 6M HCl none
reaction with 6M HCl none reaction with 15M HNO3 mild, = HTcO4
reaction with 6M NaOH
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Other Forms

number of isotopes 0 hydride(s) none
oxide(s) TcO2 Tc2O7 chloride(s) TcCl4


ionic radius (2- ion) pm ionic radius (1- ion) pm
atomic radius 136 pm ionic radius (1+ ion) pm
ionic radius (2+ ion) pm ionic radius (3+ ion) pm
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thermal conductivity 50.6 J/m-sec-deg electrical conductivity 1/mohm-cm
polarizability 11.4 A^3


source Synthetic (U fission) rel. abund. solar system log
abundance earth's crust log cost, pure $/100g
cost, bulk $/100g
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World Wide Web presentation of Chemicool Periodic Table is © Copyright 1996-99 by David D. Hsu. Some data were provided by and used with the permission of JCE Software and is owned and copyright by the Division of Chemical Education, Inc. Additional data were provided by Perkin-Elmer through Peter Lykos of IIT. The information may not be redistributed without the permission of David Hsu or JCE Software.