Scientists have formally added two new
man-made elements to chemistry's periodic table, recognizing a pair of
fleeting elements forged in a particle accelerator and lasting just
milliseconds before decaying.
In 1990, Livermore's Ken Moody, left, and Ron Lougheed,
center, joined Academician Yuri Oganessian, head of the Flerov
Laboratory of Nuclear Reactions in Dubna, Russia, to toast the beginning
of what became a 21-year collaboration to create superheavy elements.
Lawrence Livermore National Laboratory
Elements 114 and 116—yet unnamed—were
first formed in 2004 and 2006, the result of a collaboration dating to
1990 by a team of Russian and U.S. scientists at the Joint Institute for
Nuclear Research in Dubna, near Moscow. The new elements have 114 and
116 protons, respectively, in their nuclei and are the heaviest
discovered so far.
Scientists have been
creating new elements since 1940, when neptunium and plutonium were
first forged at the University of California, Berkeley. As more elements
have been created, a pattern emerged: Each new element was radioactive,
slightly heavier than the one before, and in general, more unstable.
Eventually,
scientists hope to discover new elements that might be stable, easily
studied and, perhaps, offer commercially useful properties.
Two man-made elements, Nos. 114 and 116, were added to the
periodic table after a collaboration between Russian and U.S.
scientists that began in 1990 at this cyclotron in Dubna, Russia.
Lawrence Livermore National Laboratory
Atoms of the two new elements—created
in a clash of nuclear particles—lasted only milliseconds before
decaying into simpler and more stable substances, making them hard to
study and even harder to verify.
The
panel responsible for certifying claims of new elements took three years
to confirm the discoveries. Claims involving three other new
elements—113, 115 and 118—were rejected.
"We
have to take things one atom at a time," said Paul Karol, a nuclear
chemist at Carnegie Mellon University who is chairman of the
international panel.
Elements are pure
chemical materials from which all known matter is composed. They consist
of a single type of atom distinguished by the number of protons in its
nucleus, its atomic number. The periodic table arranges the elements
based on their atomic number and allows scientists to predict
as-yet-undiscovered elements.
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