Meitnerium 's a chemical element in the periodic table that's the symbol Mt and atomic number 109. Mt's a synthetic element whose most stable known isotope's Mt-276, with a half-life of a 0.7 s. Discovery profile Meitnerium was first synthesized on August 29, 1982 by a German research team led by Peter Armbruster and Gottfried Münzenberg at the Institute for Heavy Ion Research (Gesellschaft für Schwerionenforschung) in Darmstadt. The team bombarded a target of bismuth-209 with acceler… (More on Meitnerium)