OPOpenPithMake curiosity visibleCHEMISTRY LAB / 02

The Periodic Table

118 elements, raised by their properties.

Click an element to view its atom · drag to orbit · right-drag or two fingers to pan · scroll to zoom

About Roentgenium

Roentgenium (German: [ʁœntˈɡeːni̯ʊm] ) is a synthetic chemical element; it has symbol Rg and atomic number 111. It is extremely radioactive and can only be created in a laboratory. The most stable known isotope, roentgenium-282, has a half-life of 130 seconds, although the unconfirmed roentgenium-286 may have a longer half-life of about 10.7 minutes. Roentgenium was first created in December 1994 by the GSI Helmholtz Centre for Heavy Ion Research near Darmstadt, Germany. It is named after the physicist Wilhelm Röntgen (also spelled Roentgen), who discovered X-rays. Only a few roentgenium atoms have ever been synthesized, and they have no practical application.

The text above is from the lead of the Wikipedia article “Roentgenium” (retrieved 2026-11-05), used under CC BY-SA 4.0. Read on Wikipedia · CC BY-SA 4.0

Data and notes

Column height is a linear display mapping; the shortest column is not zero. Data: PubChem, IAEA.

Solid columns are measured, frosted glass is predicted, empty frames have no value.

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