Meitnerium
[Rn] 5f¹⁴ 6d⁷ 7s² · 2 · 8 · 18 · 32 · 32 · 15 · 2
An element named after Lise Meitner, the physicist who explained nuclear fission and was passed over for the Nobel Prize that went to her collaborator Otto Hahn.
3D model
Bohr model: nucleus and electron shells from the real configuration. Valence electrons are highlighted.
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Atomic properties
- Atomic number
- 109
- Atomic mass
- 278 а.е.м. ≈
- Electron configuration
- [Rn] 5f¹⁴ 6d⁷ 7s²
- Electrons per shell
- 2 · 8 · 18 · 32 · 32 · 15 · 2
- Block
- d-block
- Group
- Cobalt group
- Period
- 7
- Electronegativity (Pauling)
- no data
- Electronegativity (Allen)
- no data
- Atomic radius
- no data
- Covalent radius
- 129 pm
- Van der Waals radius
- no data
- Ionisation energy 1
- 800 kJ/mol ≈
- Electron affinity
- no data
- Common oxidation states
- +3
- Oxidation states
- +3
Physical properties
- State at 25 °C
- unknown
- Density
- 27.5 g/cm³ ≈
- Melting point
- no data
- Boiling point
- no data
- Speed of sound
- no data
Thermal properties
- Heat of fusion
- no data
- Heat of vaporisation
- no data
- Specific heat capacity
- no data
- Thermal conductivity
- no data
Mechanical properties
- Young's modulus
- no data
- Shear modulus
- no data
- Bulk modulus
- no data
- Poisson ratio
- no data
- Mohs hardness
- no data
- Brinell hardness
- no data
Electrical and magnetic properties
- Electrical resistivity
- no data
- Magnetic ordering
- no data
- Curie point
- no data
- Néel point
- no data
- Superconducting point
- no data
Crystal structure
- Crystal structure
- face-centred cubic (fcc) ≈
- Lattice constants
- no data
Abundance
- In the crust
- 0 mg/kg
- In the ocean
- 0 mg/L
- In the universe
- 0 mg/kg
- In the human body
- 0 mg/kg
Isotopes
| Isotope | Abundance | Half-life | Decay mode |
|---|---|---|---|
| 278Mt | — | 4.5 s | α |
| 282Mt | — | 1.12 min | α |
Meitnerium-282, half-life about a minute, is the longest-lived known isotope. Meitnerium's chemistry has never been studied.
Discovery
- Year of discovery
- 1982
- Discovered by
- Peter Armbruster, Gottfried Münzenberg and colleagues
- Where
- Darmstadt, Germany
- Origin of the name
- after Lise Meitner, who explained nuclear fission
History
Münzenberg and Armbruster synthesised element 109 at Darmstadt in 1982. The first experiment produced a single atom after two weeks of bombardment.
Where it occurs
Absent from nature.
How it is produced
By nuclear fusion: bismuth-209 bombarded with iron-58 ions. It is made one atom at a time.
Role in living things
No biological role.
Safety
Only single atoms are ever handled.
Uses
Fundamental research
Curiosities
- Lise Meitner explained the mechanism of nuclear fission, but the 1944 Nobel Prize went to Hahn alone.
- The first meitnerium atom was registered on 29 August 1982, after two weeks of continuous bombardment.
- Meitnerium is one of the few elements named after a woman, along with curium.
- Meitnerium's chemical properties have never been measured; every figure is calculated.