Seaborgium - chemistry.

Seaborgium - chemistry. Seaborgium, symbol Sg, chemical element with the atomic number 106. Seaborgium is produced artificially by nuclear fusion (in which an element with larger atoms is produced by fusing two smaller atoms from other elements). Each seaborgium atom contains a large nucleus, or central mass, containing positively charged particles called protons and neutral particles called neutrons. The large number of particles in the nucleus makes the atom unstable and causes the atom to split apart into smaller components soon after it is created. The International Union of Pure and Applied Chemistry named element 106 seaborgium (Sg) to honor Nobel Laureate Glenn T. Seaborg, who codiscovered plutonium and nine other transuranium elements. Seaborgium, which was temporarily called unnilhexium, is the first element that was named for a living person. Seaborgium has the atomic number 106, which means that each Sg atom contains 106 protons in the nucleus. Scientists have created several isotopes of seaborgium, or forms of the element that contain different numbers of neutrons in the nucleus. For example, seaborgium-263 contains 106 protons and 157 neutrons (106 protons + 157 neutrons = atomic mass 263). Similarly, seaborgium-265 contains 106 protons and 159 neutrons. Seaborgium was first created and identified in 1974 by a team of researchers at the Lawrence Berkeley National Laboratory in the United States. The scientists made seaborgium by the nuclear fusion of the smaller elements californium (Cf) and oxygen (O). Scientists at the Joint Institute of Nuclear Research in Dubna, Russia, also produced seaborgium at nearly the same time in 1974. Because the seaborgium nucleus contains so many particles, the atom is unstable and undergoes spontaneous fission, a process in which the atom quickly breaks into smaller "daughter" components. When the atom splits, it releases energy in the form of electromagnetic waves and electrically charged bits of matter. This energy is known as radiation (see Radioactivity). The Berkeley scientists discovered seaborgium-263, an isotope with a lifespan of about 1 second. A joint research effort between American and Russian scientists produced the most stable isotopes of element 106, seaborgium-265 and seaborgium-266, with a lifespan of about 32 seconds and 40 seconds, respectively. The most stable isotope of this element is the seaborgium-266. Seaborgium belongs to Group 6 (VIb) on the periodic table, which also contains the naturally occurring (nonradioactive) elements chromium (Cr), molybdenum (Mo), and tungsten (W) (see Chemical Element). Both chromium and molybdenum are important trace elements (elements that are vital for health but occur in the body in very small amounts) and are key components of certain proteins and enzymes. Because elements in the same group, or column, on the periodic table often share similar properties (a pattern known as the periodic law), scientists expected seaborgium to share properties with other Group 6 elements. Supporting this expectation, scientists have found that seaborgium forms the chemical complex, SgO2Cl2, with chlorine and oxygen. This complex is analogous to complexes that molybdenum and tungsten form with chlorine and oxygen. Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.