Sunday, June 3, 2012

Element 118

In 1998, Robert Smolanczuk published some calculations which suggested that it could be possible to produce element 118 by fusing lead with krypton. In 1999, Lawrence Berkeley National Laboratory (LBNL) scientists reported the successful production of element 118 (given the temporary name ununoctium and temporary chemical symbol Uuo) by fusing lead-208 and krypton-86: 


86
36
Kr
+ 208
82
Pb
293
118
Uuo
+ n

Unfortunately, researchers, including LBNL scientists, were unable to duplicate theses results, and in 2002 the director of the laboratory announced that the original claim of the discovery of element 118 (ununoctium) had been based on data that was fabricated by a researcher and was not based on the results of a scientific investigation.

In 2006, researchers at the Joint Institute for Nuclear Research (JINR) and Lawrence Livermore National Laboratory of California announced that they had indirectly detected several nuclei of ununoctium-294, produced by colliding californium-249 atoms and calcium-48 atoms:

249
98
Cf
+ 48
20
Ca
294
118
Uuo
+ 3n

However, in 2011 the International Union of Pure and Applied Chemistry (IUPAC) said the results did not meet the criteria for the announcement of the discovery of a new element.

Further Reading
Isotopes 
History of the Periodic Table

Suggested Study Questions
  1. Give the atomic number for each of the following isotopes:
    • calcium-48
    • krypton-86
    • lead-208 
    • californium-249
    • ununoctium-294
  2. Give the mass number for each of the following isotopes:
    • calcium-48
    • krypton-86
    • lead-208 
    • californium-249
    • ununoctium-294
  3. Give the number of protons in the nucleus of each of the following isotopes:
    • calcium-48
    • krypton-86
    • lead-208 
    • californium-249
    • ununoctium-294
  4. Give the number of neutrons in the nucleus of each of the following isotopes:
    • calcium-48
    • krypton-86
    • lead-208 
    • californium-249
    • ununoctium-294
  5. It has been suggested that element 120 with a mass number of 302, and the temporary name unbinilium and temporary symbol Ubn, could be produced by bombarding plutonium-244 with iron-58. Write a possible equation for this reaction.
  6. It has also been suggested that element 120 (unbinilium, Ubn) with a mass number of 302 could be produced by fusing uranium-238 and nickel-64. Write a possible equation for this reaction.
  7. If unbinilium-302 were to be produced by fusing californium-248 with another atom, what would be the most likely element to use? Justify your answer by writing an equation for the equation.
  8. What is the most likely product of the reaction in which californium-249 atoms are fused with titanium-50 atoms? Justify your answer by writing an equation for this reaction.
  9. Based on your understanding of the arrangements of elements within the Periodic Table, which group do you think ununoctium would belong to? What would you predict the physical and chemical properties of ununoctium to be?
  10. Before 1979, element 118 had been known as eka-emanation or eka-radon because radium "emanation" is an old name for the element radon, so-called because Friedrich Ernst Dorn first noticed that radium compounds emanate, or emit, a radioactive gas, and "eka" was the prefix used by mendeleev when constructing his Periodic Table to denote an unknown element 1 place down in the same Group. Give the current names for the elements which were originally known as:
    • eka-caesium
    • eka-iodine
    • eka-boron
    • eka-aluminium
    • eka-manganese
    • eka-silicon

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