Roentgenium is a chemical element with symbol Rg and atomic number 111. It is an extremely radioactive synthetic element (an element that can be created in a laboratory but is not found in nature); the most stable known isotope, roentgenium-282, has a half-life of 2.1 minutes. Roentgenium was first created in 1994 by the GSI Helmholtz Centre for Heavy Ion Research near Darmstadt, Germany.
The Edu Periodic Table, also known as the periodic table of chemical elements, is an interactive and modern display of the chemical elements. It is widely used in chemistry, physics, and other sciences, and is generally seen as an icon of chemistry.
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