Technetium was the first element on the periodic table to be synthesised. It is rare, radioactive and has only a few uses, says Prof Allan Blackman in ep 83 of Elemental.

Dmitri Mendeleev predicted some of the properties of element 43, but it remained stubbornly undiscovered until l937.

The reason it was hard to discover is that the radioactive element doesn't really exist on Planet Earth.

Its great claim to fame is that it was the first element to be synthesised, hence its name, technetium, from the Greek tekhnetos, meaning 'artificial', says Professor Allan Blackman from the Auckland University of Technology, in episode 83 of Elemental.

Go to this episode on rnz.co.nz for more details