The science behind new superheavy element

periodic-table_element 117

There are many skills which I willingly admit are beyond my grasp: Hitting a Major League curveball; reading a Papal bull in original Latin; and being able to sculpt human forms from marble are among talents I don’t see myself picking up anytime soon.

Another aptitude which I find myself decidedly deficient is the comprehension of physics inherent in the upper end of periodic table of elements.

Consider the following:

“(It) was recently announced that physicists have created one of the heaviest elements yet, an atom with 117 protons in its nucleus,” according to Scientific American. “This jumbo-sized atom sits on the outer reaches of the periodic table where bloated nuclei tend to become less and less stable. Element 117’s existence gives scientists hope, however, that they are getting closer to discovering a rumored ‘island of stability’ where nuclei with so-called magic numbers of protons and neutrons become long-lived.”

That’s the sort of egghead knowledge that you don’t pick up in Chemistry 101 (especially if you were noted for not paying attention).

Typically, elements heavier than uranium are not usually found in nature but can be produced in laboratories.

This effort comes with a caveat, however.

“The larger an atomic nucleus gets, the more its protons repel one another with their positive charges, making it, in general, less stable, or more radioactive,” the publication reported. “Element 117, for example, has a half-life of about 50 thousandths of a second, meaning that within that time about half of it will decay into a lighter element.”

At present, element 117 has the placeholder name of ununseptium, which will be used until it is formally accepted and added to the periodic table by the International Union of Pure and Applied Chemistry.

The creation of element 117 was no trifling matter as researchers smashed calcium nuclei (with 20 protons apiece) into a target of berkelium (97 protons per atom).

The experiment was exceedingly difficult because berkelium is difficult to obtain.

“We had to team up with the only place on the planet where berkelium can be produced and isolated in significant quantities,” said Christoph Düllmann, who led experiments by the GSI Helmholtz Center for Heavy Ion Research in Darmstadt, Germany. That place is the Oak Ridge National Laboratory in Tennessee, which has a nuclear reactor that can create the rare element with a half-life of 330 days.

It took Oak Ridge about two years to build up a large enough stock of berkelium for the experiment; when about 13 milligrams had accumulated, laboratory scientists shipped it to Germany for the next stage of the project.

“At GSI, researchers accelerated calcium ions to 10 percent light-speed and sent them colliding into the berkelium,” according to the publication. “If a calcium and berkelium nucleus collided head-on, occasionally the two nuclei would stick together, fusing to form a new element with a combined total of 117 protons.”

A well-done video demonstrating the process can be found in this story by RedOrbit.

It produced about one atom per week, Düllmann said. If all that weren’t difficult enough, the scientists were not able to observe element 117 directly. Instead, they searched for its “daughter products” after it radioactively decayed by emitting alpha particles – helium nuclei with two protons and two neutrons.

“The heavy nuclei makes an alpha decay to produce element 115, and this also decays by alpha decay,” says Jadambaa Khuyagbaatar of GSI, lead author of a paper reporting the results published May 1 in Physical Review Letters.

Element 117 was first created in 2010 by a U.S.–Russian team the Joint Institute for Nuclear Research in Dubna, Russia.


5 thoughts on “The science behind new superheavy element

  1. It may well be there are conditions under which such heavy elements can exist out there in the cosmos. To me it seems desperate to expand the periodic table upwards. Typical of humanity not content with a perfectly stable set of elements about which a small fraction of the chemistry is known they play around with half lives of a fifty thousandth of a second.

    • It does seem like an awful lot of work and expense for something that exists for barely any time at all, and would appear to serve no purpose. Sometimes, however, such seemingly quixotic exercises lead to real advances.

  2. Mr.Cotton,
    As you are aware my awesomeness has no limit whatsoever. My brilliance and my insight are a matter of record on the blogoshpere which spans the entire earth, YET Having just read this, I somehow feel I just became even smarter. Therefore the validity of element 117 can now be ruled upon. Go Science!

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