Oganesson (symbol Og, atomic number 118) is the heaviest known element, a synthetic noble gas named after Yuri Oganessian. It is classified as a noble gas and sits in group 18, period 7 of the periodic table.
Overview
Oganesson is the chemical element with atomic number 118 and the symbol Og. With a standard atomic weight of [294], it is a noble gas. In the periodic table it occupies group 18 and period 7, and under standard conditions it is normally a solid. Oganesson is the heaviest known element, a synthetic noble gas named after Yuri Oganessian.
Atomic structure
An atom of Oganesson has 118 protons in its nucleus and, when neutral, 118 electrons arranged in the configuration [Rn] 5f14 6d10 7s2 7p6. Oganesson has no stable isotope; the value [294] refers to the mass number of its most stable or most commonly produced isotope.
Discovery and place in the table
Oganesson was discovered in 2002 by Joint Institute for Nuclear Research, LLNL. It follows Tennessine (Ts) and is, so far, the heaviest element ever produced.
| Atomic number | 118 |
|---|---|
| Symbol | Og |
| Atomic mass | [294] |
| Category | Noble gas |
| Group | 18 |
| Period | 7 |
| Electron configuration | [Rn] 5f14 6d10 7s2 7p6 |
| Phase at STP | Solid |
| Discovered | 2002 (Joint Institute for Nuclear Research, LLNL) |