| 释义 |
livermorium
liv·er·mo·ri·um L5222550 (lĭv′ər-môr′ē-əm)n. Symbol Lv An artificially produced radioactive element with atomic number 116 that has only been produced in trace amounts and has five observed isotopes with mass numbers ranging from 289 to 293. Its most stable isotope has a half-life of about 53 milliseconds. See Periodic Table.
[After the Lawrence Livermore National Laboratory located in Livermore, California, which collaborated in its discovery.]livermorium (lɪvəˈmɔːrɪəm) n (Elements & Compounds) a transuranic element produced by bombarding curium with calcium-20 ions. Symbol: Lv; atomic no: 116; atomic wt: 293 [C21: named after the Lawrence Livermore National Laboratory, California, scientists from which were involved in its discovery ]livermorium
livermorium, artificially produced radioactive chemical elementelement,
in chemistry, a substance that cannot be decomposed into simpler substances by chemical means. A substance such as a compound can be decomposed into its constituent elements by means of a chemical reaction, but no further simplification can be achieved.
..... Click the link for more information. ; symbol Lv; at. no. 116; mass number of most stable isotopeisotope
, in chemistry and physics, one of two or more atoms having the same atomic number but differing in atomic weight and mass number. The concept of isotope was introduced by F.
..... Click the link for more information. 292; m.p., b.p., sp. gr., and valence unknown. Situated in Group 16 of the periodic tableperiodic table,
chart of the elements arranged according to the periodic law discovered by Dmitri I. Mendeleev and revised by Henry G. J. Moseley. In the periodic table the elements are arranged in columns and rows according to increasing atomic number (see the table entitled
..... Click the link for more information. , it is expected to have properties similar to those of poloniumpolonium
, radioactive chemical element; symbol Po; at. no. 84; mass no. of most stable isotope 209; m.p. 254°C;; b.p. 962°C;; sp. gr. about 9.4; valence +2 or +4. Polonium is an extremely rare element found in uranium ores (about 0.1 gram per ton).
..... Click the link for more information. and telluriumtellurium
[Lat.,=earth], semimetallic chemical element; symbol Te; at. no. 52; at. wt. 127.60; m.p. 450°C;; b.p. 990°C;; sp. gr. 6.24 at 20°C;; valence −2, +4, or +6. Tellurium is a lustrous, brittle, crystalline, silver-white metalloid.
..... Click the link for more information. . In 1999 a research team at the Lawrence Berkeley National Laboratory in Calif. bombarded lead-208 atoms with high-energy krypton-86 ions to create, apparently, oganessonoganesson
, artificially produced radioactive chemical element; symbol Og; at. no. 118; mass number of most stable isotope 294; m.p., b.p., sp. gr., and valence unknown.
..... Click the link for more information. (element 118) atoms. The Og-293 isotope that they synthesized emitted an alpha particle to decay into Lv-289, which has a life-life of about 0.6 millisecond, which then emitted an alpha particle to decay into flerovium (element 114). Although the Berkeley laboratory retracted its claim for creating oganesson in 2001, other research teams subsequently created livermorium directly. In 2011 its creation was officially confirmed, based on work in 2004 and 2006 by Lawrence Livermore National Laboratory in Calif. and the Joint Institute for Nuclear Research in Dubna, Russia. Using isotopes provided by Livermore, the Dubna facility bombarded curium-245 with calcium-48 to produce Lv-291. The name livermorium, after the Livermore laboratory, was proposed (2011) for the element and adopted by the International Union of Pure and Applied Chemistry (IUPAC) in 2012. See also synthetic elementssynthetic elements,
in chemistry, radioactive elements that were not discovered occurring in nature but as artificially produced isotopes. They are technetium (at. no. 43), which was the first element to be synthesized, promethium (at. no. 61), astatine (at. no.
..... Click the link for more information. ; transactinide elementstransactinide elements
, in chemistry, elements with atomic numbers greater than that of lawrencium (at. no. 103), the last member of the actinide series. See transuranium elements.
..... Click the link for more information. ; transuranium elementstransuranium elements,
in chemistry, radioactive elements with atomic numbers greater than that of uranium (at. no. 92). All the transuranium elements of the actinide series were discovered as synthetic radioactive isotopes at the Univ.
..... Click the link for more information. . AcronymsSeeLV |