What Is Oganesson?
Oganesson is a chemical element with the symbol Og and atomic number 118, classified as a noble gas in Group 18.
The heaviest known element and only synthetic noble gas. Named after physicist Yuri Oganessian.
As a noble gas in Period 7 and Group 18 (Noble Gases), oganesson's placement on the table reflects its electron configuration of [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁶, which governs its bonding behavior and the type of compounds it typically forms.
Position on the Periodic Table
Oganesson is located in Period 7, the bottom row of the standard periodic table, consisting largely of radioactive and synthetic elements.
Within that row, oganesson sits in Group 18 (Noble Gases), alongside elements that share a similar number of valence electrons and, by extension, similar chemical behavior.
This position is not arbitrary — the periodic table was deliberately organized so that an element's row and column reveal its expected reactivity, bonding pattern, and physical state at a glance.
Physical & Chemical Properties
Oganesson has an atomic mass of (294) u and a density of ~7 g/cm³.
Oganesson's outer electron shell is completely filled, leaving it with almost no tendency to bond with other elements under ordinary conditions.
Electron Configuration Explained
Oganesson's electron configuration is [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁶, describing how its electrons are distributed across shells and subshells around the nucleus.
Reading the configuration in order shows electrons filling shells of increasing energy, following the standard Aufbau principle that explains how atomic structure builds up across the periodic table.
The outermost (valence) electrons shown in this configuration are what ultimately determine oganesson's chemical reactivity and the type of bonds it forms with other elements.
History & Discovery
Oganesson was formally discovered in 2002, Oganessian, identified through the careful isolation and analytical techniques typical of that era's chemical research.
Many elements from this period were anticipated by Dmitri Mendeleev's periodic table, which successfully predicted gaps corresponding to undiscovered elements well before laboratory instruments existed to confirm them directly.
What Is Oganesson Used For?
Oganesson's specific properties make it useful in several applications, including:
- Research only
- Nuclear physics
- Scientific study
- No practical uses
- Academic research
These uses reflect oganesson's underlying classification as a noble gas, since the same properties that define its category in chemistry also determine where it becomes practically useful.
Fun Facts About Oganesson
- Oganesson completes period 7 — it may not behave as a noble gas due to relativistic effects.
- Oganesson is element number 118 on the periodic table, in Period 7 and Group 18.
- Its standard atomic mass is (294) u, calculated from the natural abundance of its isotopes.
Frequently Asked Questions
What is Oganesson's atomic number?
Oganesson has atomic number 118.
What is Oganesson's chemical symbol?
Oganesson's symbol is Og.
What group and period is Oganesson in?
Oganesson is in Period 7, Group 18 (Noble Gases).
What is Oganesson's atomic mass?
Oganesson's standard atomic mass is (294) u.