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Periodic Table/Meitnerium
109

Mt

278.000

Meitnerium

Meitneriyum

Unknown
Period 7
Group 9
Solid

Meitnerium is a synthetic transactinide element with atomic number 109. It is named after Lise Meitner and is studied mainly through nuclear decay, with predicted Group 9 chemistry related to iridium.

Atomic Number

109

Atomic Mass

278 g/mol

Electron Configuration

[Rn] 5f¹⁴ 6d⁷ 7s²

Shells

2 | 8 | 18 | 32 | 32 | 15 | 2

Electronegativity

Density

37.4 g/cm³

Melting Point

Boiling Point

Discovered By

GSI Darmstadt

History

Meitnerium was synthesized in 1982 at GSI Darmstadt by bombarding bismuth-209 with iron-58. It is named after Lise Meitner, whose work was central to understanding nuclear fission.

Isotopes

Meitnerium-278

Half-life: About 4.5-9 seconds. Among the longest-lived known meitnerium isotopes; values vary by nuclear data source.
Uses
  • Nuclear decay and superheavy element research
  • Theoretical Group 9 chemistry studies
  • Relativistic calculations comparing meitnerium with iridium
Biological Role

Meitnerium has no biological role. It is synthetic, radioactive and produced only atom by atom.

Interesting Facts
  • Meitnerium is one of the few elements named after a woman scientist.
  • No confirmed chemical compound of meitnerium has been experimentally characterized yet.
  • The element name is often seen as a delayed recognition of Lise Meitner’s contribution to nuclear fission science.
Study Notes
  • Meitnerium has atomic number 109 and symbol Mt.
  • Its calculated electron configuration is [Rn] 5f¹⁴ 6d⁷ 7s².
  • Meitnerium is predicted to be a Group 9 transactinide below iridium.
  • Remember Mt for Lise Meitner and nuclear fission history.
Meitnerium FAQ
What is the atomic number of meitnerium?

The atomic number of meitnerium is 109.

What is the electron configuration of meitnerium?

Meitnerium is commonly listed with the calculated electron configuration [Rn] 5f¹⁴ 6d⁷ 7s².

What is meitnerium used for?

Meitnerium has no commercial use; it is used only in nuclear physics and theoretical chemistry research.

Who is meitnerium named after?

Meitnerium is named after Lise Meitner.

Has meitnerium chemistry been studied experimentally?

Meitnerium chemistry has not yet been characterized in the way lighter transactinides such as hassium have been studied.


HassiumPeriodic TableDarmstadtium
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