Meitnerium

Meitnerium (pronounced /maɪtˈnɜriəm/ ( listen) myet-NAIR-ee-əm) is a chemical element with the symbol Mt and atomic number 109. It is placed as the heaviest member of group 9 (or VIII) in the periodic table but a sufficiently stable isotope is not known at this time which would allow chemical experiments to confirm its position, unlike its lighter neighbours. It was first synthesized in 1982 and the most stable isotope known is Mt-276, with a hal... more

Meitnerium (pronounced /maɪtˈnɜriəm/ ( listen) myet-NAIR-ee-əm) is a chemical element with the symbol Mt and atomic number 109. It is placed as the heaviest member of group 9 (or VIII) in the periodic table but a sufficiently stable isotope is not known at this time which would allow chemical experiments to confirm its position, unlike its lighter neighbours. It was first synthesized in 1982 and the most stable isotope known is Mt-276, with a half-life of ~700 ms, although a possible isomer of the isotope Mt-270 has an apparent half-life ~1.1 s. 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 accelerated nuclei of iron-58 and detected a single atom of the isotope meitnerium-266: Historically, element 109 has been referred to as eka-iridium. The name meitnerium (Mt)... less