Superheavy element forged in lab is a first.
Scientists around the world are on a quest to find all the elements possible in the universe. Everything is made of elements, so understanding elements is a way of understanding all the matter around us. Some of these elements, hydrogen or oxygen for example, can be easily found on Earth. Others, especially atoms that are heavier than uranium, are hard to study. They have to be made in the lab and, even then, usually decay, or break down into other smaller atoms, right after they’re created.
Recently, a team of physicists from Russia and the United States created a never-before-seen superheavy element in the laboratory. Right now, it’s known simply as “element 117” or “ununseptium.” The experiment was led by Yuri Oganessian, a physicist at the Joint Institute for Nuclear Research in Dubna, Russia.
Sigurd Hofmann, a nuclear physicist in Darmstadt, Germany, told Science News that the results are “convincing.”
Those names for the element are not official. A new element doesn’t receive an official name until more teams of scientists can also make it in the laboratory. This stage of the scientific process, called verification, is important to make sure that the original experiment was not a fluke. Verification can take a long time. In February of this year, for example, element 112 finally received the official name “Copernicium,” and it had been first identified in 1996.
At the center of every atom is a nucleus, and inside the nucleus are particles called neutrons and protons. Each element has a characteristic number of protons, and inside an atom of the newly created element are 117 protons, which is why it is called “element 117.”
This illustration shows the newly found element that formed when berkelium atoms were bombarded by calcium atoms. See an animation of the bombardment.
|From animation by Kwei-Yu Chu/Lawrence Livermore National Laboratory|
The new element was created at the Joint Institute for Nuclear Research in a machine called a cyclotron. A cyclotron may sound like a roller coaster — and for atoms, it is a wild ride. A cyclotron smashes together different kinds of elements at super-high speeds, and scientists watch to see what happens just after the crash.
In this case, the scientists used a cyclotron to bombard atoms of berkelium with atoms of calcium. Specifically, an isotope, or variation, of berkelium (berkelium-249) was bombarded with an isotope of calcium, calcium-48. The calcium isotope had 28 neutrons compared with calcium’s usual 20. Add that to the usual 20 protons in calcium, and you have calcium-48.
Berkelium is a heavy element that does not occur in nature — it also had to be created in a laboratory. In fact, berkelium was created in a laboratory in Tennessee, then transported around the world to Russia for this experiment.
And what an experiment it was: For 150 days, the scientists smashed calcium-48 atoms into berkelium-249 atoms, and at the end of the experiment the team had created exactly six atoms of element 117, according to the Oak Ridge National Laboratory, where some of the other scientists on the project work. And for all that work, those six atoms didn’t last very long: After a tiny fraction of a second, they had all decayed.
A heavy atom decays when its nucleus breaks apart, and the heavy atom breaks down into smaller atoms, each having fewer protons in their nuclei than were in the original hefty atom.
It may seem like the researchers went through a lot of work for six rare atoms that quickly vanished, but the scientists are excited. They’ve been looking for element 117 for some time — both elements 116 and 118 have already been made in a laboratory, but until now no one had seen element 117.
Almost all heavy elements decay quickly, but scientists are excited because superheavy elements such as 116, 117 and 118 don’t vanish as quickly as other superheavies. Scientists have been hoping to find a group of these atoms together. Such a group would be a step toward finding an “island of stability” on the Periodic Table, and element 117 may be part of the group.
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