Roentgenium (Rg), element 111 – Learn Acer periodic table

Roentgenium

Transition metal, atomic number 111.

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.

Facts

Symbol Rg. Atomic mass 282.0 u. Group 11, period 7. Electron configuration [Rn] 5f14 6d10 7s1. Electrons per shell 2, 8, 18, 32, 32, 17, 2. State at room temperature: Solid. Melting point unknown, boiling point unknown. Discovered by Gesellschaft für Schwerionenforschung.

Element data from Wikipedia, CC BY-SA 3.0.