Chemical data for Mt - Meitnerium |


Atomic Number: 109
Atomic Weight: -266.0
Element Type: Transition Metal
Crystal Structure:
Melting Point: °C = °F = K
Boiling Point: °C = °F = K
Critical Temp: °C = °F = K
Atomic Radius: Å (Å = Angstrom = 10-10 m)
Covalent Radius: Å


On August 29, 1982, physicists at the Heavy Ion Research Laboratory, Darmstadt, WestGermany made and identified element 109 by bombing a target of Bi-209 with acceleratednuclei of Fe-58. If the combined energy of two nuclei is sufficiently high, the repulsiveforces between the nuclei can be overcome.

In this experiment a week of target bombardment was required to produce a single fusednucleus. The team confirmed the existence of element 109 by four independent measurements.The newly formed atom recoiled from the target at predicted velocity and was separatedfrom smaller, faster nuclei by a newly developed velocity filter. The time of flight tothe detector and the striking energy were measured and found to match predicted values.

The nucleus of 266X started to decay 5 ms after striking the detector. A high-energyalpha particle was emitted, producing 267/107X. This in turn emitted an alpha particle,becoming 258/105Ha, which in turn captured an electron and became 258/104Rf. This in turndecayed into other nuclides. This experiment demonstrated the feasibility of using fusiontechniques as a method of making new, heavy nuclei.