Named "hidden", used to define the metre, and briefly the fictional weakness of a superhero.
- Atomic number
- 36
- Atomic mass
- 83.798 u
- Phase
- Gas
- Electron configuration
- [Ar] 3d¹⁰ 4s² 4p⁶
- Melting point
- 115.79 K · -157.4 °C
- Boiling point
- 119.93 K · -153.2 °C
- Density
- 0.004 g/cm³
- Electronegativity
- 3
- Period / Group
- 4 / 18
- Discovery year
- 1898