Roentgenium (Rg)
"The X-Ray, a hero named for the discoverer of the invisible rays that let us see inside things."
A memorable persona to anchor Rg in your mind.
28.7
Grams per cm³
N/A
Celsius (°C)
N/A
Radius (pm)
Daily Life Link
Roentgenium has no everyday connection, used only in research.
Discovery & History
Year Discovered
1994
Discovered By
GSI Helmholtz Centre for Heavy Ion Research
Origin of Name
"The name roentgenium (Rg) was proposed by the GSI team in honour of the German physicist Wilhelm Conrad Röntgen, and was accepted as a permanent name on November 1, 2004"
Technical Properties
Atomic Mass
[280] u
Standard State
solid (expected)
Boiling Point
N/A
Electron Configuration
[Rn] 5f146d107s1
1st Ionization Energy
N/A
Electron Affinity
N/A
Oxidation States
"Roentgenium is a synthetic, highly radioactive element."
Did You Know?
It is named in honor of the German physicist Wilhelm Conrad Röntgen, who discovered X-rays in 1895.
Like darmstadtium, it was first created at the GSI in Germany in 1994 by bombarding a bismuth target with nickel ions.
It is a member of Group 11, placing it below the 'coinage metals' copper, silver, and gold. It is therefore predicted to be a noble metal.
Its most stable known isotope has a half-life of about 26 seconds.