Technetium was the first element to be made artificially. In 1937 the Italian mineralogist Carlo Perrier and the physicist Emilio Segre in Palermo analysed a piece of molybdenum foil that had been used in the cyclotron of Ernest Lawrence at Berkeley, who had sent it to Sicily at Segre's request. The foil was radioactive, and they showed that it contained a new element that filled the gap at number 43 in the periodic table, which Dmitri Mendeleev had predicted. The name comes from the Greek technetos, meaning artificial. All isotopes of technetium are radioactive, and only traces are found in nature. One isotope, technetium-99m, is the most widely used radioactive tracer in nuclear medicine, employed in millions of diagnostic scans every year.
Before and after
- December 1936Paracuellos massacres
- from 5 December 1936 to 9 October 1991Kazakh Soviet Socialist Republic
- 10 December 1936Death of Luigi Pirandello
- 17 December 1936Birth of Pope Francis
- 1937Discovery of technetium
- 1937Guernica
- 1937Nanjing Massacre
- 1937Publication of Of Mice and Men
- 1937Jahn–Teller effect
More in Science & technology
- 1923Brønsted–Lowry acid–base theory
- 1933Karl Jansky detects radio waves from the Milky Way
- 4 March 1936First flight of LZ 129 Hindenburg
- 1 February 1942Launch of Voice of America
- October 1943Streptomycin, the first antibiotic that works against tuberculosis, is discovered
- 1944Avery, MacLeod and McCarty show that DNA carries genes
The era
This moment belongs to the Modern era (1914 CE to 1945 CE), world wars and a changing world. You can also browse everything in the 20th century.