← Periodic Table
43Tc98.000
Technetium
Transition MetalTechnetium (/tɛkˈniːʃiəm/) is a chemical element with symbol Tc and atomic number 43. It is the element with the lowest atomic number in the periodic table that has no stable isotopes:every form of it is radioactive. Nearly all technetium is produced synthetically, and only minute amounts are found in nature.
Phase: SolidAppearance: shiny gray metal
2, 8, 18, 13, 2
Physical Properties
Atomic Mass98 u
Density11 g/cm³
Melting Point2430 K
Boiling Point4538 K
Molar Heat24.27 J/(mol·K)
Period5
PhaseSolid
Chemical Properties
Electron Configuration1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d5
Semantic Config[Kr] 4d5 5s2
Shells2, 8, 18, 13, 2
Electron Affinity53 kJ/mol
Electronegativity1.9
Ionization Energies
IE1: 702 kJ/molIE2: 1470 kJ/molIE3: 2850 kJ/mol
Discovery
Discovered byEmilio Segrè