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Element 19 - Potassium (K) sound

From potash, an impure form of potassium carbonate known to the ancients; symbol K from its Latin name kalium, discovered 1807. Seventh most abundant element in the earth's crust. Its radioactivity, though mild, may be one natural cause of genetic mutation in man.

Properties

Atomic Number: 19
Atomic Weight: 39.0983
Electron Configuration (at ground state): 1s22s22p63s23p64s1
Oxidation States (Bold most stable): +1
Boiling Point (K): 1033
Melting Point (K): 336.8
Density (at 300K -- g/cm3): 0.86
Atomic Volume (at 300K -- cm3/mol) 45.30
Number of stable isotopes: 2
Number of natural radioactive isotopes: 1
Mass Number (Bold naturally occurring) -- Half-Life -- Disintigration Type: 40 -- 1.28 x 109 years -- orbital electron capture
42 -- 12.36 hours -- beta particle (electron) emission
Covalent Radius (Å): 2.03
Atomic Radius (Å): 2.35
First Ionization Potential (V): 4.341
Electronegativity (Pauling's): 0.82
Specific Heat Capacity (at 300K -- J g-1 K-1): 0.757
Heat of Vaporization (kJ/mol): 76.9
Heat of Fusion (kJ/mol): 2.33
Electrical Conductivity (at 293K for polycrystalline material -- 106 (ohms)-1 cm-1): 16.4
Thermal Conductivity (at 300K -- W m-1 K-1): 102.5
Crystal Structure: Cubic, body centered
Acid-Base Properties: Very basic