Meitnerium (Mt)

Isotopes of Meitnerium 

Meitnerium is a synthetic element (an element not found in nature but that can be created in a laboratory). It was discovered in 1982 by Peter Armbruster, Gottfried Münzenber and their co-workers at Gesellschaft für Schwerionenforschung (GSI — Institute for Heavy Ion Research) in Darmstadt, Germany. Its name originates with Lise Meitner, the Austrian physicist.

Meitnerium is the seventh member of the 6d series of transition metals. Since element 112 (copernicium) has been shown to be a transition metal, it is expected that all the elements from 104 to 112 would form a fourth transition metal series, with meitnerium as part of the platinum group metals. Calculations on its ionization potentials and atomic and ionic radii are similar to those of its lighter homologue iridium, thus implying that meitnerium's basic properties will resemble those of the other group 9 elements: cobalt, rhodium and iridium.

Meitnerium is expected to be a solid under normal conditions and assume a face-centered cubic crystal structure, similarly to its lighter congener, iridium. It should be a very heavy metal with a density of around 37.4 g/cm³, which would be the second-highest of any of the 118 known elements, second only to that predicted for its neighbor hassium (41 g/cm³).

Properties of Meitnerium