Meitnerium (Mt)
Unknown properties · Radioactive · Synthetic
Meitnerium honours Lise Meitner, the physicist who co-discovered nuclear fission and was overlooked for the Nobel Prize. Only a few dozen atoms have ever been made.
Position on the periodic table
Atomic properties
| Atomic number | 109 |
|---|---|
| Atomic mass | 278 amu |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d7 |
| Noble gas shorthand | *[Rn] 5f14 6d7 7s2 |
| Electrons per shell | 2, 8, 18, 32, 32, 15, 2 |
| Valence electrons (outer shell) | 2 |
| Common oxidation states | None common |
| Electronegativity (Pauling) | Not available |
| Covalent radius (approx.) | Not available |
| First ionization energy | Not available |
| Electron affinity | Not available |
Physical properties
| State at 25 °C | Solid |
|---|---|
| Density | 37.4 g/cm³ |
| Melting point | Not available |
| Boiling point | Not available |
| Appearance | Not available |
| Radioactive | Yes |
| Origin | Synthetic (lab-made) |
Electron configuration of meitnerium
Meitnerium's ground-state electron configuration is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d7, usually shortened to *[Rn] 5f14 6d7 7s2. Its electrons occupy 7 shells (2, 8, 18, 32, 32, 15, 2), placing it in period 7 of the d-block. Explore it interactively in the electron configuration calculator.
Uses of meitnerium
- Fundamental research only
Biological role: None.
Occurrence: Entirely synthetic.
History and discovery
Discovered: 1982 — Gesellschaft für Schwerionenforschung. Name origin: Named after Lise Meitner.
First created at GSI Darmstadt in 1982 by fusing iron nuclei with bismuth.
Safety notes
Radioactive; exists for milliseconds to seconds.
Educational context only — always follow your school's laboratory rules and never handle chemicals without proper supervision. See our disclaimer.
Practice questions
Quick practice: Meitnerium
1. What is the chemical symbol of Meitnerium?
2. What is the atomic number of Meitnerium?
3. Which category does Meitnerium belong to?
4. What is the state of Meitnerium at room temperature?
5. Which period of the periodic table is Meitnerium in?
Meitnerium FAQs
What is the atomic number of meitnerium?
Meitnerium's atomic number is 109 — every meitnerium atom has 109 protons in its nucleus.
What is the symbol for meitnerium?
Mt. Named after Lise Meitner.
Is meitnerium a metal, nonmetal, or metalloid?
Meitnerium is classified as a unknown properties.
What state is meitnerium at room temperature?
At about 25 °C, meitnerium is a solid.
What is meitnerium used for?
Key uses include: fundamental research only.
Related elements
Keep working with this element
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