Technetium

Symbol: Tc
Date of discovery: 1937
Name origin: Greek technêtos
Appearance: silvery-gray
Discoverer: Carlo Perrier/Emilio Segre
Obtained from: man-made

Melting point: 2430 K
Boiling point: 4538 K
Density[kg/m³]: 11500
Molar volume: 8.63 × 10^-6 m³/mol
Protons/Electrons: 43
Neutrons: 55
Shell structure: 2,8,18,13,1
Electron configuration: [Kr]4d65s1
Oxidation state: 4,6,7
Crystal structure: body hexagonal

This rare transition metal was discovered by C. Perrier and E. Segre in 1937 in a sample of molybdenum that had been bombarded with deutrons. Since its discovery, many searches for technetium in terrestrial matter have been done. In 1962, 99Tc was isolated as a spontaneous fission product of 238Ur. Technetium is found in the spectrum of S-, M-, and N-type stars, leading to new theories of the production of heavy elements in the stars. Technetium is a silver-gray metal and is the first element to be made artificially. It has 21 isotopes, all of which are radioactive, allowing for its use in medical radioactive isotope tests.