Wednesday 13 March 2013

Flerovium

Flerovium 


Flerovium is the radioactive chemical element with the symbol Fl and atomic number 114. The element is named after Russian physicist Georgy Flyorov, the founder of the Joint Institute for Nuclear Research in Dubna, Russia, where the element was discovered. The name was adopted by IUPAC on May 30, 2012.

About 80 decays of atoms of flerovium have been observed to date, 50 directly and 30 from the decay of the heavier elements livermorium and ununoctium. All decays have been assigned to the five neighbouring isotopes with mass numbers 285–289. The longest-lived isotope currently known is 289Fl with a half-life of ~2.6 s, although there is evidence for a nuclear isomer, 289bFl, with a half-life of ~66 s, that would be one of the longest-lived nuclei in the superheavy element region.

Chemical studies performed in 2007–2008 indicate that flerovium is unexpectedly volatile for a group 14 element; in preliminary results it even seemed to exhibit noble-gas-like properties due to relativistic effects.


Discovery of Flerovium / Ununquadium

Element 114, flerovium, was first made in Dubna, Russia in 1998.

The work was a collaboration between science teams at the Joint Institute for Nuclear Research in Dubna and the Lawrence Livermore National Laboratory (LLNL) in California led by Yuri Oganessian and Ken Moody.

Subsequently the team made element 114 on a number of occasions; cumulatively this provided enough evidence for IUPAC to announce in June 2011 its acceptance of element 114′s discovery.

Flerovium was made by a fusion reaction of element 20 with element 94: calcium-48 with plutonium-244.

Calcium ions were formed into a beam in the U400 cyclotron (a particle accelerator) at Dubna, accelerating to reach 10% of the speed of light before hitting the plutonium target.


The experiment was run for 6 months. In the first 40 days, 5 x 1018 calcium ions were fired at the plutonium, resulting in the formation of a single atom of flerovium-289, which existed for 30.4 seconds before decaying.

Later, two atoms of flerovium-288 were made, allowing an approximate half-life of 2 seconds to be estimated for this isotope.

As a result of its position in Group 14 of the periodic table we might expect flerovium to be one of the ‘other metals’ with properties similar to lead with possible oxidation states of +2 and +4. Too little flerovium has been synthesized for its properties to be assessed with certainty.

Element 114′s electron configuration is [Rn] 5f14 6d10 7s2 7p2. As a result of relativistic effects, element 114 has three outer p orbitals with different symmetries: p1/2 (m=1/2), p3/2 (m=1/2), p3/2 (m=3/2). (In lighter elements the three p orbitals px, py, pz are symmetrical.)

So, how does the filled 7p1/2 subshell influence the chemical properties of flerovium? Significant spin-orbit splitting between the spherical 7p1/2 and distorted 7p3/2 orbitals meant estimates ranged from chemical inertness (a solid version of noble gas behavior) to lead-like behavior. Initial results indicate ununquadium may exhibit noble gas-like behavior.

Ununquadium (Uuq) was element 114′s temporary name until an official name was chosen by IUPAC. IUPAC has now recommended that element 114 should be named flerovium. Although this name has not yet been given final approval, there is little doubt that this will be the name chosen for element 114.

The name flerovium is in accordance with the wishes of the deputy director of Russia’s Joint Institute for Nuclear Research (JINR) who wanted element 114′s name to be derived from Flerov, in honor of George Flerov, the Russian nuclear physicist.

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 (flerovium/ununquadium) and element 116 (livermorium/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:

Flerovium / Ununquadium is harmful due to its radioactivity.

Characteristics:

  • Flerovium / Ununquadium is a synthetic radioactive metal and has only been produced in minute amounts.

Uses of Flerovium

  • Flerovium is of research interest only.