Element 109
Meitnerium (Mt)
Meitnerium (Mt) is element 109 of the periodic table, a element with unclassified properties in period 7, group 9 (d-block) with an atomic mass of 278 and is a solid at standard conditions.
At a glance
- Atomic number
- 109
- Symbol
- Mt
- Atomic mass
- 278 u
- Category
- Unclassified properties
- Period
- 7
- Group
- 9
- Block
- d-block
- Phase at STP
- solid
Electron structure
- Electron configuration
- 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p6 5f14 6d7 7s2
- Shorthand configuration
- [Rn] 5f14 6d7 7s2
- Electrons per shell
- 2, 8, 18, 32, 32, 15, 2
- Oxidation states
- +9
Physical properties
- Density
- 37.4 g/cm3
- Phase
- solid
Atomic properties
- Covalent radius
- 129 pm
- First ionization energy
- 800 kJ/mol
Notable isotopes
| Isotope | Mass | Abundance | Stability |
|---|---|---|---|
| Mt-278 | 278.15631 | — | Half-life 4.5 seconds |
Common uses
- Scientific research only
Discovery
- Year
- 1982
- Discovered by
- Peter Armbruster, Gottfried Münzenberg
- Country
- Germany