Alphabetical Index
Browse by Elements
Keyword Search
ASTM Electrolytes
Macro Etchants
Micro Etchants
Named Etchants
New Etchants
Al and Al Alloys
Cu and Cu Alloys
Fe and Fe Alloys
Ni and Ni Alloys
Carbide Etchants
Fluoride Etchants
Nitride Etchants
Other Etchants
Oxide Etchants
Phosphide Etchants
Single Crystal Etchants
Thin Film Etchants
Wafer Etchants
Help
Home
Rubidium
Symbol: Rb
Atomic Number: 37
Atomic Weight: 85.4678
Element Classification: Alkali Metal
Discovered By: R. Bunsen, G. Kirchoff
Discovery Date: 1861 (Germany)
Name Origin: Latin: rubidus (deep red); the color its salts impart to flames.
Density (g/cc): 1.532
Melting Point (°K): 312.2
Boiling Point (°K): 961
Appearance: Soft, silvery-white, highly reactive metal
Atomic Radius (pm): 248
Atomic Volume (cc/mol): 55.9
Covalent Radius (pm): 216
Ionic Radius: 147 (+1e)
Specific Heat (@20°C J/g mol): 0.360
Fusion Heat (kJ/mol): 2.20
Evaporation Heat (kJ/mol): 75.8
Thermal Conductivity (@25°C W/m K):
Debye Temperature (°K): n/a
Pauling Negativity Number: 0.82
First Ionizing Energy (kJ/mol): 402.8
Oxidation States: 1
Electronic Configuration: [Kr] 5s1
Lattice Structure: Body-Centered Cubic (BCC)
Lattice Constant (Å): 5.590
Lattice C/A Ratio: n/a
Mineral Hardness [no units]: 0.3
Brinell Hardness [/MN m-2]: 0.216