BY REBECCA JASULEVICZ
Any student who has ever taken a chemistry class is sure to know of the Periodic Table.
When Dmitri Mendeleev first published the Periodic Table in 1869, it contained 59 known elements and blank spaces for elements not yet discovered. Today, it contains 98 naturally occurring elements and 20 others that have either been synthesized in laboratories or have yet to be confirmed.
One such element is ununpentium, the recently synthesized element 115.
In 2004, Russian and American scientists claimed the discovery of element 115, but the International Union of Pure and Applied Chemistry (IUPAC) deemed the evidence to be insufficient for an official classification.
At the time, Sergei Dmitriev of the Flerov Laboratory of Nuclear Reactions in Dubna, Russia, had formally claimed discovery.
Swedish scientists of Lund University working at the G.S.I. Helmholtz Center for Heavy Ion Research in Darmstadt, Germany, have been attempting to synthesize ununpentium since its premature discovery.
New elements are typically created in laboratories when scientists bombard existing atoms with other particles. In this case, a thin film of americium-243 was assaulted with high-speed calcium-48 nuclei.
Professor Dirk Rudolph of Lund University led this work, and Rudolph said, “This was a very successful experiment and is one of the most important in the field in recent years.”
The scientists were able to synthesize one of the heaviest atoms in existence, though were only able to recognize its presence by the X-ray radiation and the gamma rays it emitted.
Though ununpentium was synthesized for these experiments, Professor Rudolph said, “There are speculations that in the course of stellar supernova explosions, the astrophysical rapid-neutron capture process may lead to super-heavy elements just at or just short of this neutron number 184.”
However, though the possibility for natural occurrence of ununpentium exists, it is highly unlikely that any human would be able to detect it before it decayed.
According to Professor Rudolph, “Based on the data from the 288-115 nuclei, this isotope has a half-life of 160 milliseconds.”
This means that half of the ununpentium decayed in 160 milliseconds, which would not have been as disheartening had the experiment created more than about thirty atoms.
The IUPAC, as well as the International Union of Pure and Applied Physics (IUPAP), still must review the study to determine whether the experiments meet the official criteria for discovery.
At this point, the element cannot be maintained for a long enough time for scientists to study its properties, though they plan to synthesize more of the unstable atom in future tests.
However, even if more is discovered about ununpentium, Professor Rudolph said, “Given the production rate – let’s say, two atoms per day – practical implications are far-fetched.”
The researchers of Lund University in Sweden hope that there is enough evidence to support the existence of ununpentium, and that it will now be allowed to join the Periodic Table officially.
Ununpentium is one step closer to being named a legitimate element, and if so, students will have one more element to memorize in chemistry class.
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