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Element 37 - Rubidium (Rb) sound

From rubidus, or red (the color its salts impart to flames); discovered 1861. Rubidium, used in electric-eye cells, is also a potential space fuel. Like potassium, it is slightly radioactive, and has been used to locate brain tumors, as it collects in tumors but not in normal tissue.

Properties

Atomic Number: 37
Atomic Weight: 85.4678
Electron Configuration (at ground state): 1s22s22p63s23p63d104s24p65s1
Oxidation States (Bold most stable): +1
Boiling Point (K): 961
Melting Point (K): 312.63
Density (at 300K -- g/cm3): 1.532
Atomic Volume (at 300K -- cm3/mol) 55.9
Number of stable isotopes: 1
Number of natural radioactive isotopes: 1
Mass Number (Bold naturally occurring) -- Half-Life -- Disintigration Type: 86 -- 18.7 days -- beta particle (electron) emission
87 -- 4.8 x 1011 years -- beta particle (electron) emission
Covalent Radius (Å): 2.16
Atomic Radius (Å): 2.48
First Ionization Potential (V): 4.177
Electronegativity (Pauling's): 0.82
Specific Heat Capacity (at 300K -- J g-1 K-1): 0.363
Heat of Vaporization (kJ/mol): 69.2
Heat of Fusion (kJ/mol): 2.34
Electrical Conductivity (at 293K for polycrystalline material -- 106 (ohms)-1 cm-1): 47.8
Thermal Conductivity (at 300K -- W m-1 K-1): 58.2
Crystal Structure: Cubic, body centered
Acid-Base Properties: Very basic