Rubidium
Alkali Metal
Rubidium (Rb) is a chemical element with atomic number 37, classified as a alkali metal. At room temperature it is a solid. It was discovered in 1861 by Robert Bunsen, Gustav Kirchhoff.
Properties
- Atomic number
- 37
- Atomic mass
- 85.468 u
- Category
- Alkali Metal
- Group
- 1
- Period
- 5
- Block
- s-block
- Electron configuration
- [Kr] 5s¹
- Phase at STP
- Solid
- Density
- 1.532 g/cm³
- Melting point
- 312.46 K (39.3 °C)
- Boiling point
- 961 K (687.9 °C)
- Electronegativity
- 0.82
- Atomic radius
- 265 pm
- Ionization energy
- 4.177 eV
- Discovery
- 1861 · Robert Bunsen, Gustav Kirchhoff
Common uses
Atomic clocks, medical imaging, research, photocells
Did you know?
So reactive it ignites spontaneously in air and creates atomic clocks.