Oganesson in the context of "Synthetic element"

An inert gas is a gas that does not readily undergo chemical reactions with other chemical substances and therefore does not readily form chemical compounds. Though inert gases have a variety of applications, they are generally used to prevent unwanted chemical reactions with the oxygen (oxidation) and moisture (hydrolysis) in the air from degrading a sample. Generally, nitrogen, carbon dioxide, and all noble gases except oganesson (helium, neon, argon, krypton, xenon, and radon) are considered inert gases. The term inert gas is context-dependent because several of the inert gases, including nitrogen and carbon dioxide, can be made to react under certain conditions.

Purified argon gas is the most commonly used inert gas due to its high natural abundance (78.3% N₂, 1% Ar in air) and low relative cost.

The noble gases (historically the inert gases, sometimes referred to as aerogens) are the members of group 18 of the periodic table: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn) and, in some cases, oganesson (Og). Under standard conditions, the first six of these elements are odorless, colorless, monatomic gases with very low chemical reactivity and cryogenic boiling points. The properties of oganesson are uncertain.

The intermolecular force between noble gas atoms is the very weak London dispersion force, so their boiling points are all cryogenic, below 165 K (−108 °C; −163 °F).

Yuri Tsolakovich Oganessian (born 14 April 1933) is an Armenian and Russian nuclear physicist who is best known as a researcher of superheavy elements. He has led the discovery of multiple chemical elements. He succeeded Georgy Flyorov as director of the Flyorov Laboratory of Nuclear Reactions at the Joint Institute for Nuclear Research in 1989 and is now its scientific director. The heaviest known element, oganesson, is named after him, only the second time that an element was named after a living person (the other is seaborgium).

A period 7 element is one of the chemical elements in the seventh row (or period) of the periodic table of the chemical elements. The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behavior of the elements as their atomic number increases: a new row is begun when chemical behavior begins to repeat, meaning that elements with similar behavior fall into the same vertical columns. The seventh period contains 32 elements, tied for the most with period 6, beginning with francium and ending with oganesson, the heaviest element currently discovered. As a rule, period 7 elements fill their 7s shells first, then their 5f, 6d, and 7p shells in that order, but there are exceptions, such as uranium.

Oganesson (₁₁₈Og) is a synthetic element created in particle accelerators, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first and only isotope to be synthesized was Og in 2002 and 2005; it has a half-life of 0.7 milliseconds.