Technetium

Technetium (Tc)

Radioactive metallic transition element. Can be detected in some stars and the fission products of uranium. First made by Perrier and Segre by bombarding molybdenum with deutrons, giving them Tc-97. Tc-99 is the most stable isotope with a half-life of 2.6*10^6 years. Sixteen isotopes are known. Organic technetium compounds are used in bone imaging. Chemical properties are intermediate between rhenium and manganese.
Atomic Number43
Atomic Weight97.90721
Mass Number85
Group7
Period5
Blockd
Protons43 p+
Neutrons42 n0
Electrons43 e-
Technetium-sample.jpg Electron shell 043 technetium.png Animated Bohr Model Enhanced Bohr Model Bohr Model Orbital Diagram

Properties

Atomic Radius
135 pm
Atomic Volume
Covalent Radius
128 pm
Metallic Radius
127 pm
Ionic Radius
64.5 pm
Crystal Radius
78.5 pm
Van der Waals radius
216 pm
Density
Boiling Point
5,150 K
Melting Point
2,445 K
Electrons per shell2, 8, 18, 13, 2
Electronegativity
2.1
Electrophilicity
1.1191961031633 eV/particle
Proton Affinity
Electron Affinity
Ionization Potential
7.119381 eV/particle
Heat of Vaporization
585 kJ/mol
Heat of Fusion
23.8 kJ/mol
Heat of Formation
678 kJ/mol
Molar Heat Capacity
Specific Heat Capacity
Thermal Conductivity
50.6 W/(m K)
Gas Basicity
Dipole Polarizability
79 a₀
C6 Dispersion Coefficient
Oxidation States-3, -1, 1, 2, 3, 4, 5, 6, 7
Color
Silver
Crystal StructureSimple Hexagonal (HEX)
Lattice Constant
2.74 Å
Bulk Modulus
Electrical Resistivity
Electron Configuration[Kr] 4d5 5s2
Magnetic Ordering
Magnetic Susceptibility
PhaseSolid
Poisson Ratio
Shear Modulus
Young's Modulus
Allotropes
Alternate Names
Adiabatic Index
Appearance
Electric Conductivity
Critical Pressure
Critical Temperature
Curie Point
Electrical
Hardness
Magnetic Susceptibility
Magnetic
Neel Point
Neutron Cross Section
Neutron Mass Absorption
Gas Phase
Quantum Numbers
Refractive Index
Space Group
Speed of Sound
Superconducting Point
Thermal Expansion
Valence Electrons
Classification
CategoryTransition metals, Transition metals
CAS GroupVIIA
IUPAC GroupVIIB
Glawe Number59
Mendeleev Number56
Pettifor Number58
Geochemical Class
Goldschmidt Classsynthetic
Radioactivity
RadioactiveYes ☢️
Decay Mode
Half-Life
Lifetime
Abundance
Abundance in Earth's crust
Abundance in Oceans
Abundance in Human Body
Abundance in Meteor
Abundance in Sun
Abundance in Universena

Isotopes of Technetium

Stable Isotopes
Unstable Isotopes
85Tc 86Tc 87Tc 88Tc 89Tc 90Tc 91Tc 92Tc 93Tc 94Tc 95Tc 96Tc 97Tc 98Tc 99Tc 100Tc 101Tc 102Tc 103Tc 104Tc 105Tc 106Tc 107Tc 108Tc 109Tc 110Tc 111Tc 112Tc 113Tc 114Tc 115Tc 116Tc 117Tc 118Tc

History

Element 43 was predicted on the basis of the periodic table, and was erroneously reported as having been discovered in 1925, at which time it was named masurium. The element was actually discovered by Carlo Perrier and Emilio Segrè in 1937. It was also found in a sample of molybdenum sent by Ernest Lawrence that was bombarded by deuterons in the Berkeley cyclotron. From the Greek word technetos, artificial

DiscoverersCarlo Perrier, Émillo Segrè
Discovery LocationItaly
Discovery Year1937
Name OriginGreek: technêtos (artificial).
Technetium is harmful due to its radioactivity
Technetium was the first element to be produced artificially

Uses

Technetium is used in nuclear medicine to carry out a number of medical tests, mainly relating to imaging and functional studies of internal bodily organs like bone scan. It is also used industrially for equipment calibration following its approval as a standard beta emitter. Mild carbon steels may be effectively protected by minute quantities of technetium, but this corrosion protection is limited to closed systems because of technetium's radioactivity. Added to iron in quantities as low as 55 part-per-million transforms the iron into a corrosion-resistant alloy.

Sources

Made first by bombarding molybdenum with deuterons (heavy hydrogen) in a cyclotron.