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As the Chase For New Elements Slows, Scientists Focus on Deepening Their Understanding of the Superheavy Ones They Already Know (nature.com)
From a report: The quest to extend the periodic table is not over, but it is grinding to a halt. Since Russian chemist Dmitri Mendeleev published his periodic table 150 years ago, researchers have been adding elements to it at the average rate of one every two or three years. Having found all the elements that are stable enough to persist naturally, researchers started to create their own, and are now up to element 118, oganesson. Although they still hope to find more, they agree that prospects of venturing beyond element 120 are dim.
"We're reaching the area of diminishing returns in the synthesis of new elements, at least with our current level of technology," says Jacklyn Gates, who works on heavy-element chemistry at the Lawrence Berkeley National Laboratory in California. As a result, research on the edge of the periodic table is shifting focus. Rather than chasing new elements, scientists are going back to deepen their understanding of the superheavy ones -- roughly speaking, those with an atomic number above 100 -- that they have already made.
Studying the chemical properties of these elements could show whether the most massive ones obey the organizing principle of the table -- which sorts elements into groups with similar behaviours on the basis of periodically recurring patterns of chemical reactivity. And although the heaviest elements decay in less than the blink of an eye, researchers still hope that they might arrive at the fabled 'island of stability': a hypothesized region of element-land where some superheavy isotopes -- atoms that have the same number of protons in their nucleus, but differing numbers of neutrons -- might exist for minutes, days or even longer.
"We're reaching the area of diminishing returns in the synthesis of new elements, at least with our current level of technology," says Jacklyn Gates, who works on heavy-element chemistry at the Lawrence Berkeley National Laboratory in California. As a result, research on the edge of the periodic table is shifting focus. Rather than chasing new elements, scientists are going back to deepen their understanding of the superheavy ones -- roughly speaking, those with an atomic number above 100 -- that they have already made.
Studying the chemical properties of these elements could show whether the most massive ones obey the organizing principle of the table -- which sorts elements into groups with similar behaviours on the basis of periodically recurring patterns of chemical reactivity. And although the heaviest elements decay in less than the blink of an eye, researchers still hope that they might arrive at the fabled 'island of stability': a hypothesized region of element-land where some superheavy isotopes -- atoms that have the same number of protons in their nucleus, but differing numbers of neutrons -- might exist for minutes, days or even longer.
>> because they're approaching the size at which quantum
>> effects no longer
I don't think so - neutrons and protons are attracted together by the strong force, which is quite strong but weakens very rapidly with distance. Protons repel each other with their positive electrical charges. The electric charge is weaker than the strong, but weakens over distance more slowly. As God builds up nuclei by adding protons their mutually repulsive force is greater than the strong force because the protons on one side of the nucleus don't feel the distant protons' strong force, but they do feel the electric force. Neutrons stabilize the nucleus by adding more strong force without electric force, but again size matters, a proton at one extreme of a uranium nucleus feels almost no strong force from the other side so adding protons doesn't help. A friend that works in the weeds of this stuff told me that as a proton detaches from a radium atom and moves a nuclear radius away feels an electrical repulsion of something like 5 POUNDS from all the other protons and no attraction from the strong force. Zooom!