Technetium

related topics
{acid, form, water}
{disease, patient, cell}
{math, energy, light}
{day, year, event}
{specie, animal, plant}
{work, book, publish}
{company, market, business}
{line, north, south}
{system, computer, user}
{math, number, function}

Technetium (play /tɛkˈnʃiəm/ tek-NEE-shee-əm) is the chemical element with atomic number 43 and symbol Tc. It is the lowest atomic number element without any stable isotopes; every form of it is radioactive. Nearly all technetium is produced synthetically and only minute amounts are found in nature. Naturally occurring technetium occurs as a spontaneous fission product in uranium ore or by neutron capture in molybdenum ores. The chemical properties of this silvery gray, crystalline transition metal are intermediate between rhenium and manganese.

Many of technetium's properties were predicted by Dmitri Mendeleev before the element was discovered. Mendeleev noted a gap in his periodic table and gave the undiscovered element the provisional name ekamanganese (Em). In 1937 technetium (specifically the technetium-97 isotope) became the first predominantly artificial element to be produced, hence its name (from the Greek τεχνητός, meaning "artificial").

Its short-lived gamma ray-emitting nuclear isomertechnetium-99m—is used in nuclear medicine for a wide variety of diagnostic tests. Technetium-99 is used as a gamma ray-free source of beta particles. Long-lived technetium isotopes produced commercially are by-products of fission of uranium-235 in nuclear reactors and are extracted from nuclear fuel rods. Because no isotope of technetium has a half-life longer than 4.2 million years (technetium-98), its detection in red giants in 1952, which are billions of years old, helped bolster the theory that stars can produce heavier elements.

Full article ▸

related documents
Iron
Ruthenium
Sodium
Distillation
Glycolysis
Biochemistry
Chemistry
Iron ore
Radon
Alcohol
Carbon nanotube
Ethylene
Dubnium
Explosive material
Azeotrope
Hydrogen peroxide
Ligand
Cement
Silicon
Titanium
Ultraviolet
Seaborgium
Hydrochloric acid
Radioactive waste
Metallic bond
Calcium carbonate
Lawrencium
Inorganic chemistry
Incandescent light bulb
Adenosine triphosphate