109Mt277.154
Transition metal

Meitnerium

Meitnerium is a synthetic superheavy metal that exists only as individual atoms produced in particle accelerators, with no natural occurrence anywhere on Earth. It falls in group 9 of the periodic table, below iridium, and its rarity is extreme — across all experiments ever run, only a modest number of atoms have ever been detected. It was named in honor of physicist Lise Meitner, one of the scientists behind the discovery of nuclear fission.

Group · Period
9 · 7
At room temp
solid
Melts at
Not yet available
Density
Not yet available
Discovered
1982

Uses

Meitnerium has no practical, industrial or medical use of any kind. Every atom ever produced has decayed away within a fraction of a second, far too quickly to be gathered, measured in bulk, or put to any application. Its value lies entirely in fundamental research — each atom detected adds a small piece to physicists’ understanding of how far the periodic table can be extended and where nuclear stability breaks down.

History

Meitnerium was first synthesized in 1982 by researchers at the GSI Helmholtz Centre in Darmstadt, Germany, who fused accelerated nuclei with a target element and identified the resulting atoms through their radioactive decay chains. It was named meitnerium in honor of Lise Meitner, recognizing her central role in twentieth-century nuclear physics. The name was formally adopted by the International Union of Pure and Applied Chemistry in 1997, as part of the same agreement that settled naming disputes for several neighboring superheavy elements.

Fun facts

  • Meitnerium is named after Lise Meitner, the Austrian-Swedish physicist who helped explain nuclear fission but was famously overlooked for the Nobel Prize awarded for that work.
  • Meitnerium was one of the first elements ever named directly after a real woman scientist, rather than a place or a mythological figure.
  • Every known isotope of meitnerium decays within a fraction of a second, among the shortest-lived elements on the periodic table.

Frequently asked questions

Does meitnerium have any real-world use?

No — meitnerium has no commercial, industrial or medical application. It's produced purely to advance basic research into nuclear physics, a single atom at a time.

How is meitnerium made?

Meitnerium is created by accelerating a beam of nuclei to tremendous speed and firing it at a metal target, so that a beam nucleus and a target nucleus occasionally fuse together. Physicists confirm each new atom by tracing the unique sequence of radioactive decays it produces as it falls apart.

Who was meitnerium named after?

Meitnerium honors Lise Meitner, the physicist who helped provide the theoretical explanation for nuclear fission in the late 1930s — work for which her longtime collaborator Otto Hahn alone received the Nobel Prize in Chemistry, an omission many historians consider a significant injustice.

Isotopes

9 known isotopes

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IsotopeNatural abundanceHalf-lifeDecay modeMass excessBinding energy / nucleonDecay width
Mt-276 0.69 s Alpha decay (100%) 141,312 keV 7,250 keV 6.61 × 10-16 eV
Mt-278 4.5 s Alpha decay (100%), Spontaneous fission 145,767 keV 7,240 keV 1.01 × 10-16 eV
Mt-282 1.1 m Alpha decay (100%), Spontaneous fission (50%) 155,455 keV 7,218 keV 6.91 × 10-18 eV
Show all 9 isotopes
Mt-266 2.1 ms Alpha decay (75%), Spontaneous fission (25%) 127,672.68 keV 7,270.76 keV 2.17 × 10-13 eV
Mt-268 21 ms Alpha decay (100%) 129,151 keV 7,271 keV 2.17 × 10-14 eV
Mt-270 0.48 s Alpha decay (100%) 130,709 keV 7,271 keV 9.50 × 10-16 eV
Mt-274 0.44 s Alpha decay (100%), Spontaneous fission 137,249 keV 7,259 keV 1.04 × 10-15 eV
Mt-275 20 ms Alpha decay (100%), Spontaneous fission (25%) 138,767 keV 7,257 keV 2.28 × 10-14 eV
Mt-277 4 ms Spontaneous fission (100%), Alpha decay (20%) 143,008 keV 7,247 keV 1.14 × 10-13 eV