Discovery date : 1982
Discovered by: Peter Armbruster, Gottfried Münzenberg and colleagues
Origin of the name: Meitnerium is named for the Austrian physicist Lise Meitner.
Allotropes :
~>MEITNERIUM is a synthetic chemical element with symbol Mt and atomic number 109. It is an extremely radioactive synthetic element.
| FACT BOX | |||
| Group | 9 | Melting point | Unknown |
| Period | 7 | Boiling point | Unknown |
| Block | d | Density (g cm−3) | Unknown |
| Atomic number | 109 | Relaive atomic mass | [278] |
| State at 20°C | Solid | Key isotopes | 276Mt |
| Electron configuration | [Rn] 5f146d77s2 | CAS number | 54038-01-6 |
| ChemSpider ID | - | ChemSpider is a free chemical structure database | |
There are 7 isotopes of meitnerium with mass numbers in the range 266 to 279. The longest lived is isotope 278 with a half-life of 8 seconds. Meitnerium was first made in 1982 at the German nuclear research facility, the Gesellschaft für Schwerionenforschung (GSI), by a group headed by Peter Armbruster and Gottfried Münzenberg. They bombarded a target of bismuth with accelerated iron ions. After a week, a single atom of element 109, isotope 266, was detected. This underwent radioactive decay after 5 milliseconds.