Physicists spot element 111.Santa brought a team of research physicists in Darmstadt, Germany, an early Christmas gift: element 111. On Dec. 20, 1994, scientists at GSI GSI - Gensym Standard Interface , the center for heavy ion heavy ion n. 1. The nucleus of a heavy element. When such nuclei are caused to collide at high velocities, new elements are created. 2. research, announced that they had detected three atoms of the new element. With 111 protons and 161 neutrons, this lab-made element has the highest atomic number atomic number, often represented by the symbol Z, the number of protons in the nucleus of an atom, as well as the number of electrons in the neutral atom. Atoms with the same atomic number make up a chemical element. seen so far. To create element 111, the physicists bombarded bismuth bismuth (bĭz`məth) [Ger. Weisse Masse=white mass], metallic chemical element; symbol Bi; at. no. 83; at. wt. 208.9804; m.p. 271.3°C;; b.p. about 1,560°C;; sp. gr. 9.75 at 20°C;; valence +3 or +5. atoms, which have 83 protons, with a beam of nickel atoms, which contain 28 protons. Signals from three atoms of element 111 appeared for less than two-thousandths of a second. The atoms then decayed into lighter elements. During decay, one of the atoms gave rise to a daughter element 109, with an atomic mass atomic mass, the mass of a single atom, usually expressed in atomic mass units of 268, and a granddaughter element 107, with a mass of 264. Scientists had never before observed these two isotopes. The discovery of element 111 caps a remarkable season for the Darmstadt lab, which in November found element 110 (SN: 11/26/94, p.356). "They used the same system to discover element 111 that they used for element 110," says Albert Ghiorso, a physicist at the Lawrence Berkeley (Calif.) Laboratory. "They just changed the target from lead to bismuth, adjusted the energy level, and lo and behold, there it was." |
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