Unknown
Meitnerium
A synthetic element with chemical properties still unconfirmed.
Atomic #109Mass[278]Blockd-blockPeriod7Group9
Mt109 · [278]
3D Atom Explorer
Inside the Meitnerium atom
Switch between Bohr and Quantum Cloud modes to compare a simple teaching model with a more realistic probability-based view, and follow the guided tour to explore the Meitnerium atom step by step.
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Electron configuration
[Rn] 5f14 6d7 7s2
A neutral Meitnerium atom has 109 electrons (equal to its proton count). Choosing a different isotope above changes only the neutron count.
Shell distribution
Shell 12 e⁻Shell 28 e⁻Shell 318 e⁻Shell 432 e⁻Shell 532 e⁻Shell 615 e⁻Shell 72 e⁻
Electrons fill inner shells before outer ones; the outermost (valence) shell drives the element's chemistry.
Properties
Physical & atomic properties
- State (room temp)
- Unknown
- Melting point
- —
- Boiling point
- —
- Density
- —
- Electronegativity
- —
- Atomic radius
- —
- 1st ionization energy
- 800 kJ/mol
- Category
- Unknown
History
Discovery & naming
- Discovered
- 1982
- Discovered by
- GSI Darmstadt team
- Origin of name
- Physicist Lise Meitner.
Notable uses
Scientific research only.
Cosmic origin
Where Meitnerium comes from
Human synthesis
Synthetic and so short-lived that its bulk properties have never been measured.
Simplified origin map — many elements form through more than one astrophysical pathway.
Summary
- Atomic number
- 109
- Atomic mass
- [278]
- Category
- Unknown
- Group · Period
- 9 · 7
- Block
- d-block
- Shells
- 2 · 8 · 18 · 32 · 32 · 15 · 2