Meitnerium was first produced at GSI in Germany by bombarding bismuth with accelerated iron nuclei. The evidence came from a detected atom and its radioactive decay. This provides a concrete example of identifying an element without collecting a visible piece of material.
FROM ELEMENT TO APPLICATION
AN ELEMENT IN CONTEXT
Why does correlating meitnerium events matter when signals are scarce?
Meitnerium nuclei in synthesis and decay experiments
FOLLOW THIS RELATIONSHIP
Distinguish an event from identity
A detector signal is an observation before it becomes an elemental assignment. In meitnerium research, the interpretation must connect sparse events with a proposed nuclear history.
Explore the model (optional)
MtFORM → INTERACTION → CONSEQUENCE
Follow the explanation in either direction. These are authored steps, not a physical clock.
Optional: check your understanding
USE THE EXPLANATION
What most strengthens a nuclear assignment from scarce signals?
Atomic identity, reference properties and structure models
INTERACTIVE 3D109 visible sites
An electron censusDrag to rotate · scroll or pinch to zoom
[Rn] 5f14 6d7 7s2. Grouping electrons by principal shell connects the neutral-atom configuration to periodic-table patterns.
What this representation means
A three-dimensional counting diagram. Dots are count markers, not measured electron positions; spherical placement and spacing are arbitrary. There are no electron trajectories here. Orbitals describe quantum states.
For superheavy elements, this configuration is a theoretical assignment. It does not establish measured bulk chemistry or a material state.
Loading reference properties…
HISTORY & HUMAN DISCOVERY
Lise Meitner honored in a newly identified nucleus
Meitnerium was first identified at GSI in 1982, before the discovery of hassium despite its higher atomic number. The order reflects which nuclear reactions and patterns were experimentally accessible. Its name honors Lise Meitner, whose work included protactinium and the interpretation of nuclear . International adoption in 1997 separated the naming milestone from the original event that established element 109.
1982
Discovery
GSI identifies element 109 through nuclear decay evidence.
1997
Name adopted
Meitnerium, Mt, becomes the internationally agreed name.
Meitnerium is produced artificially and observed as extremely scarce radioactive atoms. No natural occurrence as a material resource is established. Its experimental existence is supported by nuclear evidence, while a macroscopic metal sample remains unavailable. This distinction prevents a periodic-table illustration from being mistaken for a photographed specimen.
The configuration and expected relationship to iridium are predictions for this superheavy element. Ordinary compound chemistry and bulk physical properties have not been experimentally established. Calculations include relativistic effects because a simple extension of lighter group 9 behavior may miss important changes in electronic energies and bonding.
Each section links its supporting references. Descriptions and diagrams were authored for this atlas. Source checks completed. Source checks dated 2026-09-06.
CITE THIS PAGE
Family labels and the group-3 layout are teaching conventions. A table position does not establish an unknown bulk property. Electronic configurations refer to neutral atoms; ions and material environments require their own account.
Read each reference property together with its units, conditions and the reference information below.
Not yet recorded: electron affinity, second ionization energy, ground-state term symbol, van der waals radius, thermal conductivity, specific heat capacity, electrical resistivity, crystal structure, lattice parameter a, space group, abundance in seawater, abundance in the universe, annual production, supply-risk listing, hazard classification, biological role, cas registry number, pubchem cid, wikidata item. These families are declared and awaiting an ingestion run against the source each names; they are listed here rather than shown as empty rows.
Physical
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Phase at 20 °C
Not recorded
293.15 K, 101.325 kPa
Melting point
Not recorded
at standard pressure unless noted
Boiling point
Not recorded
101.325 kPa
Density
Not recorded
solids and liquids at 293 K; gases at 273 K and 101.325 kPa
Atomic and electronic
Intended reference: Pauling electronegativity scale · Widely tabulated; original in The Nature of the Chemical Bond
Electronegativity
Not recorded
Pauling scale
First ionization energy
Not recorded
gas-phase neutral atom, ground state
Covalent radius
Not recorded
single-bond covalent radius
Common oxidation states
Not recorded
states met in ordinary compounds; not exhaustive
Occurrence and identity
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Abundance in the crust
Not recorded
upper continental crust, mass fraction
Has stable isotopes
Noderived
Discovery year in CE
1982 CEderived
WHERE IT SITS AMONG ITS NEIGHBORS
Electronegativity across period 7
Ra 0.9 Pauling · Radium
Electronegativity across period 7. Exact values.
Ra
0.9
Ac
1.1
Th
1.3
Pa
1.5
U
1.38
Np
1.36
Pu
1.28
Am
1.13
Cm
1.28
Bk
1.3
Cf
1.3
Es
1.3
Fm
1.3
Md
1.3
No
1.3
Lr
1.3
Electronegativity down group 9
Co 1.88 Pauling · Cobalt
Electronegativity down group 9. Exact values.
Co
1.88
Rh
2.28
Ir
2.2
The trend uses the same reference-property values as the periodic table. Elements with no recorded value are left out of the line rather than drawn at zero.
