Meitnerium
transition metalProperties
| Property | Value |
|---|---|
| Atomic Mass | 278 amu |
| Category | transition metal |
| Group | 9 |
| Period | 7 |
| Electron Configuration | [Rn] 5f14 6d7 7s2 |
| Oxidation States | 9, 8, 6, 4, 3, 1 |
| Discovered By | Peter Armbruster, Gottfried Munzenberg, GSI Helmholtzzentrum (1982) |
About Meitnerium
Meitnerium is element 109, named after Lise Meitner — the physicist who worked out the theory of nuclear fission in 1939 and watched Otto Hahn collect the Nobel Prize for the chemistry side of the same discovery. Putting her name on a transactinide was a long-overdue correction to that omission. The first atom was made at GSI in Darmstadt in 1982 by firing iron-58 ions at a bismuth-209 target; cold fusion gave them exactly one detection, surviving about 5 milliseconds before alpha decay. The longest-lived known isotope, Mt-278, hangs on for about 4.5 seconds. No one has run a chemistry experiment on Mt — half-lives that short, combined with single-atom production rates, leave nothing to react with. Sitting under iridium in group 9, the predictions are for a very dense (~28 g/cm³), high-melting noble metal, but the same relativistic effects that scrambled lawrencium's electron configuration are expected to bend Mt's chemistry away from a clean iridium analog.
Fun Fact
Meitnerium honors Lise Meitner, who first explained nuclear fission in 1939 — despite this monumental contribution, she was passed over for the Nobel Prize, making the naming of element 109 after her a poetic, if delayed, form of scientific justice.
Common Uses
- Cold-fusion synthesis target for testing Pb/Bi-projectile reactions
- Decay-chain anchor for confirming bohrium and other neighbors
- Probing relativistic shifts in 6d-block configurations
- Cross-section data for shell-stabilization models
- No commercial applications