109MtMeitnerium278[Rn] 5f¹⁴ 6d⁷ 7s²
unknown probably transition metal
Meitnerium
Meitnerium is a chemical element with symbol Mt and atomic number 109. It is an extremely radioactive synthetic element (an element not found in nature that can be created in a laboratory). The most stable known isotope, meitnerium-278, has a half-life of 7.6 seconds.
A stylized shell model. Electrons are quantum objects, not particles following these literal paths. Sizes and motion are illustrative.
Electrons by shell
Electron configuration
5f14
6d7
7s2
86 is the [Rn] core total across six shells.
At a glance
- Atomic number
- 109
- Atomic mass
- 278 u
- Phase
- Solid
- Density
- 37.4 g/cm³
- Melting point
- Unavailable
- Boiling point
- Unavailable
- First ionization energy
- Unavailable
- Electronegativity
- Unavailable
- Electron affinity
- Unavailable
- Molar heat capacity
- Unavailable
- Period
- 7
- Appearance
- Unavailable
Conditions and isotopes affect measured properties. Some properties of short-lived elements are predicted. Electronegativity uses the Pauling scale.
Keep exploring
Explore the stories, imagery, and reference data in more depth. Properties with no value in the reference are marked unavailable.