Element (109)

Element 109, chemical element; for physical constants see Periodic Table. Peter J. Armbruster and his co-workers in West Germany at the Heavy Ion Research Laboratory (GSI) at Darmstadt produced element 109 and confirmed its existence by four independent measurements on Aug. 29, 1982. It was produced by bombarding bismuth-209 with iron-58 nuclei. The recoiling product atom was separated by a newly developed velocity filter. The new element decayed by consecutive alpha-particle emissions to element 107 in 5 ms and then to element 105 in 22 ms. element 105 became element 104 by electron capture and this decayed by spontaneous fission.