111Rg[282]
Roentgenium
Unknown propertiesSuper-heavy elements made in labs a few atoms at a time. Their chemistry is still being studied.
[Rn] 5f¹⁴ 6d⁹ 7s²
- Atomic number
- 111
- Atomic mass
- [282]
- Protons
- 111
- Neutrons
- 171
- Electrons
- 111
- Shells
- 2, 8, 18, 32, 32, 17, 2
- State at 25 °C
- Unknown
- Position
- Group 11, period 7
Proton (+)Neutron (0)Electron (−)
Discovered byGSI Darmstadt, 1994Peter Armbruster: 6 elementsSigurd Hofmann: 3 elements
Named after Wilhelm Röntgen, who discovered X-rays.
Did you know?
- It sits below gold in the table.
- Only a few atoms have been made.
Where it's found
- Made only in laboratories, a few atoms at a time
What it's used for
- Scientific research only
Try it
There's no safe home experiment for Roentgenium. Explore it with the animated atom above instead.