Atomic number: 109
Year discovered: 1982
Discovered by: Peter Armbruster, Gottfried Münzenber, and their co-workers at Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Germany.
- Lise Meitner (1878-1968) was a distinguished Austrian physicist, whose main personal achievement (among many others) was the explanation of the relation between beta and gamma rays.
- She was born in Vienna on November 7, 1878, the third of eight children of a Viennese lawyer.
- After receiving her doctorate, in 1906, she went to Berlin, in 1907, and joined the chemist Otto Hahn in research on radioactivity; she also studied under Max Planck and for a time was his assistant.
- During their three decades of joint work, she and Hahn discovered protactinium and several other radioactive substances.
- Lise Meitner, with her nephew Otto R. Frisch, after clarifying the physical characteristics of the division of a heavy atomic nucleus, proposed, early in 1939, the name “fission” for the process.
- In August, 1982, the first atom of the element meitnerium with atomic number 109 was detected at the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Germany.
- The isotope of element 109, that was discovered, has an atomic mass number of 266 (that is, 266 times heavier than hydrogen).
- The new element was produced by fusing an iron and a bismuth atom together in a reaction that produces a neutron.
- This was achieved by accelerating the iron atoms to high energy in the heavy ion accelerator UNILAC at GSI.
- Element meitnerium was formerly known as unnilennium (Une) which is the Latin equivalent for the number “109”.
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Information about other elements may be seen at this Chemical Elements List.
A special unit about words that include chemo-, chem- may be seen here.