Technetium

Technetium Element Properties

d42
Mo
Molybdenum
d43
Tc
Technetium
d44
Ru
Ruthenium
General
NameTechnetium
SymbolTc
Number43
Group Number7
GroupTransition metals
Blockd
Density11.5 g/cm3
Atomic Weight98.9062 g/mol
Atomic Volume8.5 cm3/mol
Discover1939


States
StateSolid
Melting Point2430 K
Boiling Point4538 K
Triple PointNil
Critical PointNil
Heat of Fusion33.29 kJ/mol
Heat of Vaporization585.2 kJ/mol


Energies
First Ionization Energy702.4 kJ/mole
Second Ionization Energy1472.4 kJ/mole
Third Ionization Energy2850.2 kJ/mole
Electronegativity1.9
Electron Affinity53 kJ/mole
Specific Heat0.21 J/gK
Heat Atomization677 kJ/mole atoms


Oxidation and Electrons
Shells2,8,18,14,1
Electron Configuration[Kr] 4d5 5s2
Minimum Oxidation Number-3
Maximum Oxidation Number7
Minimum Common Oxidation Number0
Maximum Common Oxidation Number7


Appearance and Characteristics
Crystal Structurehexagonal
CharacteristicsRadioactive, man made
Colorsilvery gray
Usesmedical imaging agents
Hardnessmohs
ToxicityNone


Reactions
Reaction with Airmild, w/ht, =>Tc2O7
Reaction with 6M HClNone
Reaction with 15M HNO3mild, =>HTcO4
Reaction with 6M NaOHNone


Other Forms
Number of Isotopes0
HydrideNone
OxideTcO2 Tc2O7
ChlorideTcCl4


Radius
Atomic Radius136 pm
Ionic Radius (1+ ion)Nil
Ionic Radius (1- ion)Nil
Ionic Radius (2+ ion)Nil
Ionic Radius (2- ion)Nil
Ionic Radius (3+ ion)Nil


Conductivity
Thermal Conductivity50.6 J/m-sec-deg
Electrical ConductivityNil
Polarizability11.4 A3


Abundance
SourceSynthetic (U fission)
Relation Abundance Solar SystemNil
Abundance Earth's CrustNil


d42
Mo
Molybdenum
d43
Tc
Technetium
d44
Ru
Ruthenium