   #copyright

Bohrium

2007 Schools Wikipedia Selection. Related subjects: Chemical elements


              107              seaborgium ← bohrium → hassium
              Re
             ↑
             Bh
             ↓
             (Ups)

                                  Periodic Table - Extended Periodic Table

                                                                   General
                                     Name, Symbol, Number bohrium, Bh, 107
                                         Chemical series transition metals
                                              Group, Period, Block 7, 7, d
                                      Appearance unknown, probably silvery
                                                    white or metallic gray
                                                   Atomic mass (272) g/mol
                       Electron configuration perhaps [Rn] 5f^14 6d^5 7s^2
                                                  (guess based on rhenium)
                               Electrons per shell 2, 8, 18, 32, 32, 13, 2
                                                  Phase presumably a solid
                                            CAS registry number 54037-14-8
                                                                References

   Bohrium ( IPA: /ˈbɔː(h)riəm/), also called eka-rhenium, is a chemical
   element in the periodic table that has the symbol Bh and atomic number
   107. It is a synthetic element whose most stable isotope, Bh-272, has a
   half-life of 10 seconds.

History

   It was synthesized in 1976 by a Soviet team led by Y. Oganessian at the
   Joint Institute for Nuclear Research at Dubna, who produced isotope
   ^261Bh with a half-life of 1-2 ms (later data gave a half life of
   around 10 ms). They did this by bombarding bismuth-204 with heavy
   nuclei of chromium-54.

   In 1981 a German research team led by Peter Armbruster and Gottfried
   Münzenberg at the Gesellschaft für Schwerionenforschung (Institute for
   Heavy Ion Research) in Darmstadt were also able to confirm the Soviet
   team's results and produce bohrium, this time the longer-lived Bh-262.

   The Germans suggested the name nielsbohrium to honour the Danish
   physicist Niels Bohr. The Soviets had suggested this name be given to
   element 105 (dubnium).

   There was an element naming controversy as to what the elements from
   101 to 109 were to be called; thus IUPAC adopted unnilseptium ( IPA:
   /ˌjuːnɪlˈsɛptiəm/, symbol Uns) as a temporary, systematic element name
   for this element. In 1994 a committee of IUPAC recommended that element
   107 be named bohrium. While this conforms to the names of other
   elements honoring individuals, where only the surname is taken, it was
   opposed by many who were concerned that it could be confused with
   boron. Despite this, the name bohrium for element 107 was recognized
   internationally in 1997.

   Retrieved from " http://en.wikipedia.org/wiki/Bohrium"
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   with only minor checks and changes (see www.wikipedia.org for details
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