Technetium

Technetium (symbol: Tc) is a chemical element with atomic number 43. It is a transition metal with a silvery-gray appearance. All of its isotopes are radioactive, making it the lightest element to have no stable isotope.

Because its isotopes decay rapidly, technetium is extremely rare in nature. Small amounts can be found in uranium ore, where it is produced by natural fission. Most technetium used is produced in nuclear reactors or particle bombardment equipment.

Discovery

Position 43 on the periodic table remained empty for a long time; many scientists claimed to have found the element, but their claims were never confirmed. In 1937, it was isolated from a sample from Palermo, Italy, using material from a particle accelerator in the United States. The name comes from the Greek word technetos, meaning 'made by art' or 'artificial'.

Properties

Technetium belongs to the same group as manganese and rhenium. It has a high melting point and is known to adopt various oxidation states. When added in small amounts to ordinary steel, it greatly reduces corrosion, though this application is limited by its radioactivity.

Isotopes and medical use

The Tc-99m isotope is one of the most widely used agents in nuclear medical imaging. It emits gamma radiation that decays very quickly, allowing doctors to visualize the function of bones, heart, kidneys, and glands while keeping the patient's radiation exposure low. It is produced from a Tc-99m generator, which is derived from molybdenum-99.