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Unbibium

physical science Maturity 11-13 Next article →

Unbibium is a hypothetical chemical element that scientists have not yet created. It is also known as element 122 or eka-thorium. Because it has not been officially discovered, it uses the temporary IUPAC name unbibium and the symbol Ubb. In the periodic table, unbibium is expected to be the fourth element of the 8th period. It would also be the second element of a group called the superactinides.

Island of Stability derived from Zagrebaev
Island of Stability derived from Zagrebaev

Researchers often study superheavy elements to find the "island of stability." This is a theoretical region where certain isotopes might last much longer than others. Unbibium is expected to fall within this range. Specifically, the isotope 306Ubb might be more stable because it is predicted to have a magic number of 184 neutrons. A magic number occurs when a nucleus has a specific amount of particles that helps it stay together.

Island of Stability derived from Zagrebaev
Island of Stability derived from Zagrebaev

Creating unbibium is a massive scientific challenge. Most attempts use a process called fusion-evaporation. In this method, scientists fire a beam of heavy ions at a target material. In 1972, researchers at the Joint Institute for Nuclear Research tried to create it using hot fusion. In 1978, a team at the GSI Helmholtz Center bombarded an erbium target with xenon-136 ions. Neither experiment succeeded in detecting any unbibium atoms.

Superheavy decay modes predicted
Superheavy decay modes predicted

In 2000, the GSI Helmholtz Center performed a similar experiment with much higher sensitivity. They used a calcium-48 beam and a californium-249 target. Even with this improved method, they did not find the element. These results show that making such heavy elements requires even better technology. Scientists hope to eventually reach a sensitivity of 1 femtobarn to get better results.

Superheavy decay modes predicted
Superheavy decay modes predicted

There was once a famous claim regarding unbibium in nature. In 2008, physicist Amnon Marinov claimed to find unbibium-292 in natural thorium deposits. This would have been the first new natural element found in 69 years. However, the scientific community was very skeptical of this claim. Later experiments used accelerator mass spectrometry, which is 100 times more sensitive, and they found nothing.

IBA nuclear shells
IBA nuclear shells

Chemically, unbibium is expected to behave somewhat like cerium or thorium. However, strange physics called relativistic effects might change its behavior. These effects can alter how electrons are arranged around the nucleus. For example, its electron configuration might be [Og] 7d1 8s2 8p1 instead of what its position in the g-block suggests. This makes the chemistry of superheavy elements very difficult to predict.

IBA nuclear shells
IBA nuclear shells

Future attempts to find unbibium may require entirely new methods. Some scientists suggest using multi-nucleon transfer reactions instead of fusion-evaporation. This is because as elements get heavier, they tend to undergo spontaneous fission. Spontaneous fission is when a nucleus splits apart on its own. This process becomes much more common for elements starting around atomic number 122.

Superheavy decay modes predicted
Superheavy decay modes predicted

Currently, there are no immediate plans to synthesize unbibium. Most research facilities are focusing on discovering elements 119, 120, and 121 first. To find unbibium, scientists may need to use a chromium beam with a californium target. This specific reaction could help reach the predicted magic number of 184 neutrons. Until then, unbibium remains a fascinating mystery of the periodic table.

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File:Superheavy decay modes predicted.png
Superheavy decay modes predicted.png
File:Island of Stability derived from Zagrebaev.svg
Island of Stability derived from Zagrebaev.svg
File:IBA nuclear shells.svg
IBA nuclear shells.svg
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