A brittle metalloid used since antiquity as eye cosmetic, and now as a flame retardant.
- Atomic number
- 51
- Atomic mass
- 121.76 u
- Phase
- Solid
- Electron configuration
- [Kr] 4d¹⁰ 5s² 5p³
- Melting point
- 903.78 K · 630.6 °C
- Boiling point
- 1,860 K · 1,586.9 °C
- Density
- 6.697 g/cm³
- Electronegativity
- 2.05
- Period / Group
- 5 / 15
- Discovery year
- Ancient