Rubidium was discovered in 1861 by German chemists Robert Bunsen (1811-99) and Gustav Kirchhoff (1824-87), in the mineral lepidolite through the use of a spectroscope.
Name: Rubidium
Symbol: Rb
Atomic number: 37
Atomic weight: 85.468
State: solid
Group, period, block: 1, 5, s
Color: grey white
Classification: alkali metal
Electron configuration: 5s1
2,8,18,8,1
Physical properties
Density: 1.532 g/cm-3
Melting point: 312.46 K,39.31 °C,102.76 °F
Boiling point: 961 K,688 °C,1270 °F
Atomic properties
Oxidation states: 1
Electronegativity: 0.82 (Pauling scale)
Ionization energies: 1st: 403 kJ·mol-1
Covalent radius: 220±9 pm
Van der Waals radius: 303 pm
- Rb
Electron Configuration
Isotopes
There are two naturally occurring isotopes of rubidium exist, 85Rb, and 87Rb.