Atomic number 111
Roentgenium
Transition metal
No photo: here’s why
Roentgenium is a synthetic element made only in vanishingly small, intensely radioactive amounts - its atoms decay so quickly that no piece big enough to see or photograph has ever existed.
Quick facts
- Atomic mass
- 282.00
- Group
- 11
- Period
- 7
- State (STP)
- unknown
- Electronegativity
- –
- Common ox. states
- +3, +5
Properties
[Rn] 5f¹⁴ 6d⁹ 7s²
- Ionization energy
- –
- Electron affinity
- –
- Melting point
- –
- Boiling point
- –
How dangerous is it?
A purely synthetic element that has only ever existed as a few atoms for tiny fractions of a second before decaying away.
- RadioactiveImmediate
It is highly radioactive in theory, though its atoms last only moments and never build up.
Made and measured only inside accelerator labs using remotely controlled tools.
How it bonds· family overview
Roentgenium (Rg) is a synthetic super-heavy element produced one atom at a time. Its position predicts d-block transition-metal chemistry - multiple oxidation states, oxide and halide salts - but only a handful of atoms have ever existed, so the chemistry is largely inferred from group trends.
