Russian scientists add new element to periodic table

[Susan Gawarecki <loc@icx.net>]

Russian scientists add new element to periodic table 

By DAVID KINNEY 

(July 15, 1999 2:44 a.m. EDT http://www.nandotimes.com) - Physicists in
Russia have created a new, super-heavy element that lasted a
surprisingly long 30 seconds before disintegrating, according to
a report in Thursday's issue of the journal Nature. Using an atom
smasher to bombard plutonium with calcium ions, the physicists
created an element with an atomic weight of 114. 

The newest addition to the periodic table has yet to be named. 

Ninety-four elements exist in nature. Scientists have spent 60
years creating elements in the lab, registering 21 so far. But
some of the more recent elements were so unstable that they
disintegrated in milliseconds. 

For decades, physicists have theorized the existence of
super-heavy manmade elements with a much longer life. These
elements would make up an "island of stability." 

In the study, researchers at the Joint Institute for Nuclear
Research in Dubna, Russia, reported creating two atoms of
element 114 that lasted for as long as 30 seconds before
flickering out. This, they say, is proof the island exists. 

The discovery, and more recent creations of even heavier
elements, have no practical applications as far as today's
scientists know. 

But for academics, it's thrilling. The study of super-heavies could
shed light on supernovas and origins of the universe. And
chemists are interested in how they bond with compounds. 

The new manmade elements are numbered according to how
many protons are in their nuclei, not by their order of discovery.
Numbers 95 through 112 were created between 1944 and
1996. In the past year, scientists have created not just 114, but
also 116 and 118. The ones in between have not yet been
created. 

For decades, scientists thought one isotope, or version, of
element 114 - with 114 protons and 184 neutrons - would be
very stable because its nucleus would have a full complement of
neutrons and protons. No more could be squeezed inside. 

Late last year, the Dubna scientists made an isotope of element
114 with 175 neutrons. In March, the lab created another 114
isotope, but it had only 173 neutrons and was therefore less
stable than the first one they created. 

This year, another major lab trying to create elements, Lawrence
Berkeley National Laboratory in California, forged the heaviest
element yet, 118, and when it decayed, it morphed into element
116, then an isotope of 114 with even fewer neutrons than
Dubna's. It lasted for milliseconds. 

These three types of 114 are just off the "island of stability,"
scientists say, because they are all short of the 184 neutrons
needed. But physicists say they are in "shallow water," and that's
proof enough. 

If they can create a 114 isotope with 184 neutrons, they would
reach real stability: perhaps a life measured in years. 

One physicist, Albert Ghiorso of Lawrence Berkeley, said he is
skeptical the Russians really did create such an element. He
said that with their setup, it is too difficult to pinpoint a single
atom among all the collision byproducts. 

But Neil Rowley, of the Institute for Subatomic Research in
France, is convinced the Dubna observations are real.
"Everything behaves the way it ought to," he said. 
-- 
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Oak Ridge Reservation Local Oversight Committee, Inc.
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