Periodic TableAll elementsMeitnerium
No. 109
Mt
278 u
Element · Unknown

Meitnerium

Meitnerium (鿏, symbol Mt) is chemical element number 109, an Unknown in period 7, group 9 of the periodic table, with a standard atomic weight of about 278. Named after Lise Meitner. Only a handful of atoms have ever been produced.

Period 7Group 9[Rn] 5f¹⁴ 6d⁷ 7s²

Properties

Atomic number109
SymbolMt
Atomic mass278 u
CategoryUnknown
Period7
Group9
Electron configuration[Rn] 5f¹⁴ 6d⁷ 7s²
Electronegativity
Covalent radius
Density37.4 g/cm³
Melting point
Boiling point
DiscoveryGSI, 1982

Overview

Named after Lise Meitner. Only a handful of atoms have ever been produced. Element 109, Meitnerium (Mt), is an Unknown found in period 7, group 9. Most of its properties still await further experimental confirmation.

With 2 electrons in its outermost shell, Meitnerium bonds accordingly; full configuration [Rn] 5f¹⁴ 6d⁷ 7s². Its physical state follows from its melting and boiling points; it has a density around 37.4 g/cm³.

Common applications range across Research. On the safety side, it carries a high hazard rating. It was first described by GSI in 1982. The periodic trends guide explains the underlying patterns.

Electron shells

Mt109

Electrons per shell: 2 · 8 · 18 · 32 · 32 · 15 · 2

Main uses

Hazard

HighRadioactive

Compounds containing Meitnerium

No compounds in this knowledge base contain Meitnerium yet.

Data sources

Atomic mass uses IUPAC (CIAAW) standard atomic weights; the covalent radius is from Cordero et al. (2008). Verify on the RSC Periodic Table, PubChem and Wikipedia. Educational reference only.