Oganesson
Definition and meaning of Oganesson in chemistry.
![Oganesson element card: symbol Og, atomic number 118, atomic mass [294], electron configuration [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁶, Noble gas, group 18, period 7.](/assets/images/terms/oganesson-chemical-element.webp)
Oganesson is a highly radioactive, human-made element with the symbol Og and atomic number 118. It is the heaviest element that scientists officially recognize on the periodic table today. This synthetic element sits in the final column of the table, ending period 7.
In more detail
Oganesson sits with the noble gases in group 18 at the end of the periodic table. However, its massive nucleus alters its electron structure through relativistic effects. Instead of forming neat shells, its electrons smear out into a uniform, cloud-like shape.
This unique layout makes oganesson much more reactive than other noble gases. Computer models suggest it can bond easily with highly reactive elements like fluorine and chlorine. This chemical behavior is very different from helium, neon, or argon.
Furthermore, oganesson is expected to be a solid semiconductor at room temperature rather than a gas. A semiconductor is a material that conducts electricity under some conditions but not others. A common student misconception is that oganesson is a gas that does not react.
In reality, scientists expect it to be a reactive solid because of its heavy size. Oganesson is also extremely radioactive and decays in less than a millisecond. Its short life means scientists must study it one single atom at a time. The element completes the seventh row and represents the current limit of atomic discovery.
Key facts
| Field | General Chemistry |
|---|---|
| Symbol | Og |
| Atomic number | 118 |
| Atomic mass | [294] u |
| Category | Noble-Gas |
| Most stable isotope | Oganesson-294 |
Scientists produce oganesson only for advanced research using a high-energy particle accelerator called a cyclotron. Inside this machine, they shoot a beam of calcium-48 ions at a californium-249 target. This collision fuses the nuclei to create one atom of the new element. Because oganesson decays so quickly, scientists must identify it by tracking its breakdown products.
Frequently asked questions
Why is oganesson placed in group 18?
It is placed in group 18 because it continues the electron configuration pattern of the noble gas column.
Can oganesson form chemical compounds?
Yes, theories suggest it can form compounds with fluorine and chlorine due to its highly active outer electrons.
Has anyone seen oganesson with their eyes?
No, scientists have only created a few atoms, and they decay in less than a thousandth of a second.
Related terms
Sources & references
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