Rg
Roentgenium · element 111
Unknown, Probably Transition Metal · Solid at room temperature
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.
Key facts
Atomic mass
282 u
how heavy one atom is
Phase (room temp.)
Solid
Density
28.7 g/cm³
how tightly packed it is
Period
7
its row in the periodic table
Group
11
its column in the periodic table
Block
D-block
the neighbourhood it lives in
Electron configuration
*[Rn] 5f14 6d10 7s1
where its electrons live
Shells
2 · 8 · 18 · 32 · 32 · 17 · 2
electrons in each layer, inside to out
Discovered by
Gesellschaft für Schwerionenforschung
who found it
Source: Wikipedia