Meitnerium (Mt): Electron Configuration and Properties
Meitnerium (Mt): Electron Configuration and Properties
Electron configuration [Rn] 7s2 5f14 6d7 · group 9 · period 7 · Ar [278]
Meitnerium data
- Atomic number
- 109
- Relative atomic mass
- [278]
- Group
- 9
- Period
- 7
- Block
- d
- Category
- Transition metal
- Electron configuration
- [Rn] 7s2 5f14 6d7
- Full configuration
- 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d7
- Electrons per shell
- 2, 8, 18, 32, 32, 15, 2 (K L M N O P Q)
- Valence electrons
- 9
- Electronegativity (Pauling)
- no data
- First ionisation energy
- no data
- Atomic radius (van der Waals)
- no data
- State at room temperature
- Solid
- Melting point
- no data
- Boiling point
- no data
- Density
- no data
- Common oxidation states
- +9, +8, +6, +4, +3, +1
- Discovered
- 1982
Source: PubChem (NIH, accessed 13 Nov 2026); atomic mass: IUPAC standard atomic weight.
Electron shell diagram
K 2 · L 8 · M 18 · N 32 · O 32 · P 15 · Q 2
Orbital diagram (outer electrons)
About meitnerium
With atomic number 109, meitnerium (Mt) has 109 protons in its nucleus and 109 electrons as a neutral atom. It is a transition metal in group 9, period 7, d-block. The element was discovered in 1982. It is named after Lise Meitner. Its bulk properties have never been measured because only a few atoms have been made; it is expected to be a solid at room temperature.
Meitnerium electron configuration
The electron configuration of meitnerium is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d7, or in short [Rn] 7s2 5f14 6d7. Its electrons occupy 7 shells: K = 2, L = 8, M = 18, N = 32, O = 32, P = 15, Q = 2. For transition metals, valence electrons are counted from the 7s and 6d subshells: 2 + 7 = 9, matching group 9. For this superheavy element the configuration is a theoretical prediction.
Filling order: 1s2(2) → 2s2(4) → 2p6(10) → 3s2(12) → 3p6(18) → 4s2(20) → 3d10(30) → 4p6(36) → 5s2(38) → 4d10(48) → 5p6(54) → 6s2(56) → 4f14(70) → 5d10(80) → 6p6(86) → 7s2(88) → 5f14(102) → 6d7(109)
Uses of meitnerium
Meitnerium has no practical use outside research, because it can only be made a few atoms at a time in particle accelerators.
Safety
Only a handful of meitnerium atoms have ever been made and they decay very quickly, so it is never handled in an ordinary laboratory.
Other elements in group 9
Frequently asked questions
What is the electron configuration of meitnerium?
The electron configuration of meitnerium (Mt, atomic number 109) is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d7, or [Rn] 7s2 5f14 6d7 in short. By shell: 2, 8, 18, 32, 32, 15, 2.
How many valence electrons does meitnerium have?
Meitnerium has 9 valence electrons.
Which group and period is meitnerium in?
Meitnerium is in group 9, period 7, d-block.
What is the atomic mass of meitnerium?
Meitnerium has no stable isotope, so the mass number of its longest-lived isotope, [278], is given.
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