Meitnerium (Mt) – element 109
Meitnerium is a chemical element with the symbol Mt and atomic number 109. It is a unknown (probably transition metal) in group 9, period 7 of the periodic table (d-block), and is a solid at room temperature.
Meitnerium (Mt) has atomic number 109, atomic mass [278] and electron configuration *[Rn] 5f14 6d7 7s2.
Meitnerium facts
| Symbol | Mt |
|---|---|
| Atomic number | 109 |
| Atomic mass | [278] |
| Category | unknown (probably transition metal) |
| Group | group 9 |
| Period | 7 |
| Block | d-block |
| Phase at 20 °C | Solid |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d7 |
| Noble-gas notation | *[Rn] 5f14 6d7 7s2 |
| Electrons per shell | 2, 8, 18, 32, 32, 15, 2 |
Bohr model and shells
Meitnerium has 109 electrons in 7 shells: 2, 8, 18, 32, 32, 15, 2. Full configuration and noble-gas notation are in the table; work out any element or ion with the electron configuration calculator.
Physical and atomic properties
| Density | 37.4 g/cm³ |
|---|---|
| Discovered by | Gesellschaft für Schwerionenforschung |
Use the atomic mass in the molar mass calculator for any formula containing Mt.
Position in the periodic table
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Frequently asked questions
What is the atomic mass of meitnerium?
The atomic mass of meitnerium is [278] (mass number of its longest-lived isotope, since it has no stable isotope).
What is the electron configuration of meitnerium?
Meitnerium has 109 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 6d⁷, or *[Rn] 5f¹⁴ 6d⁷ 7s² in noble-gas notation. Electrons per shell: 2, 8, 18, 32, 32, 15, 2.
Is meitnerium a metal?
Yes. Meitnerium is a unknown (probably transition metal).
Where is meitnerium on the periodic table?
Meitnerium is in group 9, period 7, in the d-block.
Data: Periodic-Table-JSON (CC BY-SA 3.0); standard atomic weights from IUPAC (abridged). Values in brackets are the mass number of the longest-lived isotope.