The 117th chemical element in the periodic table was prepared

An international team of scientists from Russia and the USA, which includes two departments of the National Energy Laboratories and two universities, prepared the new superheavy element with atomic number 117. The life time of the new element, now prepared for the first time in the laboratory, verifies the assertion that superheavy elements are found in An "island" of stability in the periodic table.

"The discovery of the 117th element is the culmination of a decade-long journey aimed at expanding the periodic table and writing the next chapter in the study of heavy elements," said scientist Yuri Oganessian, one of the main researchers in the project.

The team confirmed the existence of element 117 from observation of decay patterns obtained following the bombardment of a radioactive berkelium target by calcium ions. The success of the experiment depended on the availability of special detection means at the particle accelerator facility in Dubna (near Moscow), in unique facilities for the production of ions and their separation in Oak Ridge (USA), and special capabilities for analyzing nuclear information at the Livermore Laboratory (in California, USA).

"This is a major breakthrough in science," says Livermore Laboratory Director George Miller. "The discovery of the new element provides new insights into the composition of the universe and is a testament to the power of science and technology of joint institutions."

"This collaboration, which led to the discovery of element 117, proves the high importance of joint work between scientists from different countries and institutions when they are faced with complex scientific challenges," adds one of the research partners.

The research journey, which lasted two years, began at the isotope facility in Oak Ridge with a 250-day irradiation to obtain 22 milligrams of berkelium. In the next step, 90 days were required to separate and purify the bercellium, another 150 days of bombarding the bercellium target with ions and in the last step the analysis of the information and the review of the results by the entire team. The whole process led to obtaining the target substance in raclium whose half-life was 320 days.

In the experiment, six atoms of element 117 were created. For each atom, the team looked at its alpha decay from atom 117 to 115 and from there to 113 and so on, until it eventually split into two lighter elements. In total, 11 new "neutron-rich" isotopes were created, which brings the researchers another step closer to the "island of stability" guaranteed for the super-heavy elements.

"Island of stability" is a concept in nuclear physics that refers to the possible existence of a region beyond the current periodic table where new superheavy elements containing special numbers of neutrons and protons will exhibit increased stability. Such an island would extend the periodic table to even heavier elements and support a longer isotopic lifetime to aid researchers in their experiments.

Element 117 was the only missing element in column 7 (the halogens) of the periodic table. On their way to the island of stability, the researchers initially skipped element 117 due to the difficulty of obtaining the target material in raclium. The decay patterns for the new isotopes observed in these experiments, the closest the researchers have ever come to an island of stability, support the general trend of increased stability in superheavy elements with larger numbers of neutrons in the nucleus. These findings support the existence of this island of stability.

"The findings fill the gap that existed and advance us increasingly from foundation 116 - on the edge of the island of stability," says one of the researchers.

The current discovery brings to six the number of new elements discovered by this team (113, 114, 115, 116, 117 and 118 - the heaviest element so far). This is the second new element discovered by the Oak Ridge team (61 and 117). In addition, this laboratory contributed to the discoveries of seven new elements in total.

Since 1940, 26 new elements have been added to the periodic table in addition to uranium. "These new elements expand our understanding of the universe and provide us with important tests of nuclear theories," notes one of the researchers. "The existence of an island of stability, a completely theoretical idea in the sixties of the last century, provides the possibility of further expansion of the periodic table accompanied by scientific breakthroughs in the physics and chemistry of heavy elements."

The research findings were published in the scientific journal Physical Review Letters.

Animation of the experiment

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