meitnerium

meitnerium mītnĭr´ēəm [key], artificially produced radioactive chemical element symbol Mt at. no. 109 mass number of most stable isotope 276 m.p., b.p., sp. gr., and valence unknown. Situated in Group 9 of the periodic table it is expected to have properties similar to those of iridium .

In 1982 a German research team led by P. Armbruster and G. Münzenberg at the Institute for Heavy Ion Research at Darmstadt bombarded bismuth-209 atoms with iron-58 ions. On the tenth day of the experiment, one atom was unambiguously identified as an isotope of element 109 with mass number 266 and a half-life of 3.4 msec. The Germans suggested the name meitnerium to honor the Austrian-Swedish physicist and mathematician Lise Meitner . This name was recognized internationally in 1997. The most stable isotope of meitnerium, meitnerium-276, has a half-life of 0.72 sec.

See also synthetic elements transuranium elements .

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

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The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.