Wednesday 13 March 2013

Ununtrium

Ununtrium 


Ununtrium is the temporary name of a chemical element with the temporary symbol Uut and atomic number 113. It is an extremely radioactive synthetic element (an element that can be created in a laboratory but is not found in nature); the most stable known isotope, ununtrium-286, has a half-life of 20 seconds. Ununtrium was first created in 2003 by the Joint Institute for Nuclear Research in Dubna, Russia.

In the periodic table, it is a p-block transactinide element. It is a member of the 7th period and is placed in the boron group, although no chemical experiments have been carried out to confirm that it behaves as the heavier homologue to thallium in the boron group. Ununtrium is calculated to have some similar properties to its lighter homologues, boron, aluminium, gallium, indium, and thallium, although it should also show several major differences from them. Unlike all the other p-block elements, it is even predicted to show some transition metal character.

Discovery of Ununtrium

Research scientists at the Joint Institute for Nuclear Research in Dubna, Russia and the Lawrence Livermore National Laboratory (LLNL), California believed they had made element 113, ununtrium, in Dubna, Russia in 2003. The work was a collaboration between science teams led by Yuri Oganessian and Ken Moody.

The team gathered data indicating that element 113 had been made by alpha decay of element 115. Element 115 was synthesized by fusion of element 20 with element 95: calcium-48 with americium-243.

The experiment began on July 14, 2003, and ended on August 10, 2003. Calcium ions were formed into a beam in a cyclotron (a particle accelerator) and fired at a target layer of americium deposited on titanium foil. Four atoms of element 115 (ununpentium) may have been produced, which then decayed to element 113 (ununtrium). 

The researcher’s data indicates one atom of ununtrium-283 and three atoms of ununtrium-284 were made. 

In 2011, The International Union of Pure and Applied Chemistry (IUPAC) reviewed the work done in Dubna and at the LLNL, and did not accept the discovery of ununtrium.

The report stated, “the results are encouraging but do not meet the criteria for discovery because of the paucity of events, the lack of connections to known nuclides, and the absence of cross-bombardments.” 

As a result of its position in the periodic table, ununtrium would be expected to be classed as one of the “other metals” and to have similar properties to the metal thallium. Too little of the element has been synthesized for this to be confirmed.

The joint teams at JINR in Dubna and Lawrence Livermore in California have published evidence for the synthesis of elements 113, 114, 115, 116, 117 and 118.

IUPAC has accepted the discoveries of element 114 (ununquadium) and element 116 (ununhexium). It has not yet considered the evidence for the discovery of element 117 (ununseptium).

IUPAC requires stronger evidence before it will confirm the synthesis of element 113 (ununtrium), element 115 (ununpentium), or element 118 (ununoctium).

Appearance and Characteristics

Harmful effects:

Ununtrium is harmful due to its radioactivity.

Characteristics:
  • Ununtrium is a synthetic radioactive metal.

Uses of Ununtrium
  • Ununtrium is of research interest only.