The symbol of a human hand reflects the fact that the element is created artificially, and its name means ‘artificial’.

Fact Box

Uses

The gamma-ray emitting technetium-99m (metastable) is widely used for medical diagnostic studies. Several chemical forms are used to image different parts of the body.

Technetium is a remarkable corrosion inhibitor for steel, and adding very small amounts can provide excellent protection. This use is limited to closed systems as technetium is radioactive.

History

Technetium long tantalised chemists because it could not be found. We now know that all its isotopes are radioactive and any mineral deposits of the element had long disappeared from the Earth’s crust. (The longest lived isotope has a half life of 4 million years.) Even so, some technetium atoms are produced as uranium undergoes nuclear fission and there is about 1 milligram of technetium in a tonne of uranium. Claims in the 1920s to have found this element, or at least to have observed its spectrum, cannot be entirely discounted.