|
Proposed Name
| Atomic Number: |
109 |
| Atomic Symbol: |
Mt |
| Atomic Weight: |
265 |
| Electron Configuration: |
[Rn]7s25f146d7 |
History
On August 29, 1982, physicists at the Heavy Ion Research Laboratory, Darmstadt, West
Germany made and identified element 109 by bombing a target of Bi-209 with accelerated
nuclei of Fe-58. If the combined energy of two nuclei is sufficiently high, the repulsive
forces between the nuclei can be overcome.
In this experiment a week of target bombardment was required to produce a single fused
nucleus. 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 separated
from smaller, faster nuclei by a newly developed velocity filter. The time of flight to
the 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-energy
alpha 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 turn
decayed into other nuclides. This experiment demonstrated the feasibility of using fusion
techniques as a method of making new, heavy nuclei.
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