Technetium

Technetium is a radioactive chemical element that has the chemical symbol Tc and has the atomic number 43. It is the lightest synthetic element.

Chemistry of Technetium

The color of technetium is silvery-grey and is a crystaline metal. In chemistry it is placed in a group of metal elements named the transition metals. The chemistry of technetium is similar to rhenium and manganese.

The isotope ^99mTc is used in nuclear medicine. It is used for many diagnostic tests. It has a short half-life. ⁹⁹Tc is used as a source of beta particles without emitting gamma rays. The ion that has oxygen and technetium bonded together (TcO₄^-) is named the pertechnetate ion. The pertechnetate ion could be used as to prevent anodic corrosion in steel.

History

Before the element was found, many of the properties of element 43 were predicted by Dmitri Mendeleev. Mendeleev noticed a gap in his periodic table and named the element in the gap eka-manganese. In 1937 the technetium isotope ⁹⁷Tc was the first element to be artificially produced. This was the reason why he named it Technetium as in Greek, τεχνητος means "artificial". Most technetium made on Earth is a by-product of fission of uranium-235 in nuclear reactors. It is extracted from nuclear fuel rods. On earth, technetium occurs naturally only in uranium ores as a product of spontaneous fission. The amount of technetium in the ore is very small but has been measured. The longest half-life of Technetium is 4.2 million years (⁹⁸Tc). This means that its detection in red giants in 1952 helped support the theory that stars can produce heavier elements.