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technetium (Tc)




A radioactive metallic element in group VIIB of the periodic table; a translation element. Technetium does not occur naturally on Earth but was discovered in 1937 by Emilio Segré and Carlo Perrier in bombarded molybdenum – the first element to be made artificially. It is now recovered from the fission products of nuclear reactors. Technetium is chemically very like rhenium.


atomic number 43
relative atomic mass 99
relative density 11.5
melting point 2,140°C (3,884°F)
boiling point 5,030°C (9,086°F)


Related category

   • INORGANIC CHEMISTRY