Editing Meitnerium (section)

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'''Meitnerium''' is a [[synthetic element|synthetic chemical element]]; it has [[Chemical symbol|symbol]] '''Mt''' and [[atomic number]] 109. It is an extremely [[radioactive]] synthetic element (an element not found in nature, but can be created in a laboratory). The most stable known isotope, meitnerium-278, has a [[half-life]] of 4.5 seconds, although the unconfirmed meitnerium-282 may have a longer half-life of 67 seconds. The element was first synthesized in August 1982 by the [[GSI Helmholtz Centre for Heavy Ion Research]] near [[Darmstadt]], Germany, and it was named after [[Lise Meitner]] in 1997. 

In the [[periodic table]], meitnerium is a [[d-block]] [[transactinide element]]. It is a member of the [[period 7 element|7th period]] and is placed in the [[group 9 element]]s, although no chemical experiments have yet been carried out to confirm that it behaves as the heavier [[Homologous series|homologue]] to [[iridium]] in group 9 as the seventh member of the 6d series of [[transition metal]]s. Meitnerium is calculated to have properties similar to its lighter homologues, [[cobalt]], [[rhodium]], and iridium.