Technetium (Tc)

From Wikipedia, the free encyclopediaTechnetium (/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.

Technetium in the periodic table

SymbolTc
Atomic number43
Group7
Period5
Blockd
Element categoryTransition Metal

Physical properties

Phase at STPSolid
Density11 g/cm3
Atomic weight98 u
Melting point2430 K
2156.85 °C
3914.33 °F
Boiling point4538 K
4264.85 °C
7708.73 °F

Atomära egenskaper

Electronegativity (Pauling Scale)1.9
Electron affinity53 kJ/mol
Ionization energies
1702 kJ/mol
2 1470 kJ/mol
3 2850 kJ/mol

Electron configuration

Electron configuration1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d5 5s2
Electrons per shell2, 8, 18, 13, 2

History

Discovered1937
Discovered byCarlo Perrier
Emilio Segrè