Technetium-99m (99mTc) is a metastable nuclear isomer of technetium-99, symbolized as 99mTc, that is used in tens of millions of medical diagnostic procedures annually, making it the most commonly used medical radioisotope in the world.
The first technetium-99m generator, 1958. A 99mTc pertechnetate solution is being eluted from 99Mo molybdate bound to a chromatographic substrate
A technetium injection contained in a shielded syringe
Technetium scintigraphy of a neck of a Graves' disease patient
Technetium is a chemical element; it has symbol Tc and atomic number 43. It is the lightest element whose isotopes are all radioactive. Technetium and promethium are the only radioactive elements whose neighbours in the sense of atomic number are both stable. All available technetium is produced as a synthetic element. Naturally occurring technetium is a spontaneous fission product in uranium ore and thorium ore, or the product of neutron capture in molybdenum ores. This silvery gray, crystalline transition metal lies between manganese and rhenium in group 7 of the periodic table, and its chemical properties are intermediate between those of both adjacent elements. The most common naturally occurring isotope is 99Tc, in traces only.
Technetium
Periodisches System der Elemente (1904–1945, now at the Gdańsk University of Technology): lack of elements: 84 polonium Po (though discovered as early as in 1898 by Maria Sklodowska-Curie), 85 astatine At (1940, in Berkeley), 87 francium Fr (1939, in France), 93 neptunium Np (1940, in Berkeley) and other actinides and lanthanides. Old symbols for: 18 argon Ar (here: A), 43 technetium Tc (Ma, masurium), 54 xenon Xe (X), 86 radon, Rn (Em, emanation)
Chloro-containing coordination complexes of technetium (99Tc) in various oxidation states: Tc(III), Tc(IV), Tc(V), and Tc(VI) represented.
The first technetium-99m generator, unshielded, 1958. A Tc-99m pertechnetate solution is being eluted from Mo-99 molybdate bound to a chromatographic substrate
