The new finding will appear in the October issue of the journal Physical Review C. But it isn't time to officially add the new element to the periodic table quite yet.
Before that can happen, the discovery needs to be confirmed. It's particularly important in this case because research into element 118 has a checkered history.
In 1999 a team from Lawrence Berkeley National Laboratory, in Berkeley, California, announced that it had created element 118, only to retract the claim when it was discovered that one of the scientists had faked some data.
"Because of the previous history on this subject, one has to be very cautious in drawing conclusions until the result is confirmed," said George Bertsch, a physicist at the University of Washington in Seattle who was not involved in the experiment.
Stoyer agrees. "We saw something interesting, and the way we've interpreted it, it's element 118," he said. "But you need someone else to duplicate it. A fundamental tenet of science is reproducibility."
But it might be a while before the experiment is repeated. "You're working with californium 249, which is fairly radioactive," Stoyer said. "Not many labs in the world either want to work with it or have the capabilities to work with it."
Island of Stability?
Element 118 and most other elements heavier than uranium are highly unstable, decaying far too quickly for scientists to study how they behave.
So researchers are seeking a theoretical "island of stability"—a group of super-heavy elements that might hang around long enough to allow their properties to be looked at in detail.
One island of stability exists for uranium and thorium, which persist in nature for long periods of time even though their neighbors on the periodic table decay very quickly.
Nobody is quite sure, however, what precise combination of protons and neutrons are needed for the next island of stability.
Stoyer thinks that it might require 120 to 126 protons and about 184 neutrons.
But Bertsch, of the University of Washington, thinks that the new discovery, if confirmed, may show that scientists have already overshot the ideal number of protons.
"The interesting thing is that one is seeing the [element] lifetimes go down as one is making [elements] heavier by adding protons," he said.
Unfortunately, he added, "the island requires many more neutrons than one is able to do with these experiments. So one can't actually see it if one is just skirting by the edge."
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