Oganesson (Og)
Oganesson (Og) is a synthetic element with atomic number 118, making it the heaviest element on the periodic table. Discovered in 2006 through collaborative efforts at Russian and American research facilities, oganesson is classified as a transuranium element, meaning it has an atomic number greater than uranium (92). It occupies Group 18 of the periodic table, known for its noble gases, and is the only synthetic member of this group. The element has a very short half-life of 0.89 milliseconds, and its most stable isotope, oganesson-294, decays rapidly, primarily through alpha decay.
Due to the limited production—only three atoms of oganesson have been created so far—its physical and chemical properties remain largely unknown. It is theorized to exist as a gas at standard conditions, but definitive physical characteristics like melting and boiling points remain unmeasured. The production of oganesson is labor-intensive and primarily conducted in research institutions, and as of now, it does not have any practical applications beyond basic scientific inquiry. Understanding oganesson further requires more extensive experimentation to discover its potential characteristics and uses.
Subject Terms
Oganesson (Og)
- Element Symbol: Og
- Atomic Number: 118
- Atomic Mass: [294]
- Group # in Periodic Table: 18
- Group Name: No information
- Period in Periodic Table: 7
- Block of Periodic Table: p-block
- Discovered by: Joint Institute for Nuclear Research, Lawrence Livermore National Laboratory (2006)
Oganesson is the heaviest synthetic element in the periodic table. Its chemical symbol is Og, its atomic number is 118, and its relative atomic weight is 294. In the periodic table, it is located in Period 7 of Group 18, falling right after the element tennessine. The electronic configuration for oganesson is [Rn] 5f146d107s27p6, where Rn stands for the element radon. Oganesson is a transuranium element and occupies position 118 in the periodic table. Hence, it is also known as element 118 and eka-radon. A transuranium element is one with atomic number higher than 92, the atomic number for uranium. All transuranium elements are artificially made except for plutonium isotopes 244 and 239. Oganesson is the only synthetic member of Group 18. All the other elements—noble gases—of Group 18 are naturally occurring.
Ununoctium and its symbol, Uuo, were the temporary name and symbol given by the International Union of Pure and Applied Chemistry (IUPAC). The IUPAC derived the name "ununoctium" from the Latin equivalent one-one-eight, where un means "one" and oct means "eight," words that represent its atomic number. In January 2016, the IUPAC confirmed the existence of the element and, in June, approved its co-discoverers' proposal of oganesson and the symbol, Og, in honor of Yuri Oganessian (b. 1933), the discoverer of superheavy elements.
The creation of oganesson was declared on October 16, 2006, by scientists working together at two facilities: the Joint Institute for Nuclear Research (JINR) in Dubna, Russia, and the US Department of Energy’s Lawrence Livermore National Laboratory. Using a cyclotron, the team bombarded the isotope californium-249 with ions of calcium-48. A cyclotron is a machine used to accelerate charged particles to create particles with high energies. This process produced oganesson-294 plus three free neutrons. This isotope had a half-life of a mere 0.89 milliseconds. During the bombardment process, the californium target was irradiated at an energy level of 245 million electron volts (MeV), and the procedure created a total of 1.6 × 1019 calcium ions over the course of 1,080 hours. But only three atoms of oganesson were produced.
In 1999, scientists working at the Lawrence Berkeley National Laboratory in California attempted to make element 118 and announced that they had succeeded. They created element 118 by bombarding the atoms of two elements: lead-208 and krypton-86. In 2002, however, the team withdrew its claim after its findings were rejected by the IUPAC.
Physical Properties
Oganesson is an artificially made element, which means it can be created only in laboratories. Thus, little is known about the physical properties because of the extremely short half-life and also because less than a handful of oganesson atoms have been created as of mid-2016. The standard state of an element is defined as its state at 298 kelvins (K), or 25 degrees Celsius. It is theorized that it is a gas at this temperature. The melting point, boiling point, and density are unknown.
Chemical Properties
Studying the physical and chemical properties of oganesson has been challenging insofar as only three atoms have ever been produced, and they decayed within fractions of seconds. Nonetheless, its most stable isotope is oganesson-294, with a half-life of 0.89 milliseconds. Oganesson decays to another transuranium element—namely, livermorium-290—by emitting an alpha particle nearly a millisecond after oganesson’s creation. Alpha decay is a process of radioactive decay in which an unstable radioactive element loses two protons and two neutrons. These two protons and two neutrons are together known as an alpha particle. An alpha particle looks similar to a helium atom, which also has two neutrons and two protons. During the process of alpha decay, a larger unstable nucleus attempts to turn into a smaller more stable nucleus.
The periodic table is divided into elements that are metals, nonmetals, and metalloids. The nonmetals are additionally classified into two groups: halogens and noble gases. Due to its position in the periodic table, oganesson is a noble gas and a nonmetal. The heaviest element of the noble gases, it is positioned under the elements helium, neon, argon, krypton, xenon, and radon. Because it falls right below radon, oganesson is expected to reflect radon’s chemical properties.
Applications
Oganesson can only be produced in research centers. The scientists who produce the element need to devote many days to make only a few atoms of oganesson. As a result, manufacturing the element on a large-scale is a difficult, arduous process. The short half-life makes it difficult to study its chemical and physical characteristics. Hence, as of 2016, oganesson has no uses outside basic research. More atoms need to be produced to understand the element’s properties and its potential uses.
Bibliography
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