Chemical data for K - Potassium |


Atomic Number: 19
Atomic Weight: 39.0983
Element Type: Alkali Metal
Crystal Structure: Cubic Face Centered
Melting Point: 63.38°C = 146.084°F = 336.53 K
Boiling Point: 759.0°C = 1398.2°F = 1032.15 K
Critical Temp: °C = °F = K
Atomic Radius: 2.77 Å (Å = Angstrom = 10-10 m)
Covalent Radius: 2.03 Å
Electronegativity: 0.82


(English, potash - pot ashes; L.. kalium, Arab qali, alkali) Discovered in 1807 byDavy, who obtained it from caustic potash (KOH); this was the first metal isolated byelectrolysis.


The metal is the seventh most abundant and makes up about 2.4% by weight of the earth'scrust. Most potassium minerals are insoluble and the metal is obtained from them only withgreat difficulty.

Certain minerals, however, such as sylvite, carnallite, langbeinite, and polyhalite arefound in ancientlake and sea beds and form rather extensive deposits from which potassiumand its salts can readily be obtained. Potash is mined in Germany, New Mexico, California,Utah, and elsewhere. Large deposits of potash, found at a depth of some 3000 ft inSaskatchewan, promise to be important in coming years.

Potassium is also found in the ocean, but is present only in relatively small amounts,compared to Sodium.