chemical element wi atomic number 43 an seembol Tc / From Wikipedia, the free encyclopedia
Technetium is the chemical element wi atomic number 43 an seembol Tc. It is the lawest atomic number element wioot ony stable isotopes; every fairm o it is radioactive. Nearly aw technetium is produced synthetically, an anly minute amoonts are foond in naitur. Naiturally occurrin technetium occurs as a spontaneous fission product in uranium ore or bi neutron capture in molybdenum ores. The chemical properties o this sillery gray, crystalline transeetion metal are intermediate atween rhenium an manganese.
Mony o technetium's properties wur predictit bi Dmitri Mendeleev afore the element wis discovered. Mendeleev notit a gap in his periodic table an gae the undiscovered element the provisional name ekamanganese (Em). In 1937, technetium (specifically the technetium-97 isotope) acame the first predominantly airtificial element tae be produced, hence its name (frae the Greek[τεχνητός]error: {{lang}}: text has italic markup (help), meanin "airtificial").
Its short-lived gamma ray-emitting nuclear isomer—technetium-99m—is uised in nuclear medicine for a wide variety o diagnostic tests. Technetium-99 is uised as a gamma ray-free soorce o beta pairticles. Lang-lived technetium isotopes produced commercially are bi-products o fission o uranium-235 in nuclear reactors an are extractit frae nuclear fuel rods. Acause na isotope o technetium haes a hauf-life langer than 4.2million years (technetium-98), its detection in 1952 in red giants, which are billions o year auld, helped bolster the theory that starns can produce hivier elements.