Electronic data		Thermal data		Steric data
Shells: 2,8,8,1 Orbitals: [Ar] 4s1 Electronegativity: 0.9, 0.8 1. Ionization potential: 4.3407 eV 2. Ionization potential: 31.625 eV 3. Ionization potential: 45.72 eV Oxidation states: 1 Electrical conductivity: 0.139 10^6		Melting point: 63.25 °C Boiling point: 759.9 °C Specific heat: 0.75 J/gK Heat of fusion: 2.334 kJ/mol Heat of vaporization: 79.870 kJ/mol Thermal conductivity: 1.024 W/cmK		Atomic radius: 2.77 Å Ionic radius: 1.51 Å () Covalent radius: 2.03 Å Atomic volume: 45.46 cm³/mol Density (293 K): 0.862 g/cm³ Crystal structure: Cubic: Body centered

Legend     Pocket calculator

Nuclide	Abundance [%]	Mass	Spin	Halflife	Decay mode	Decay tree
39K	93.22	38.9637	3/2	--	stable	--
40K	0.118	39.974	4	1.28E09y	-,+	View
41K	6.77	40.9618	3/2	--	stable	--
42K	0	41.963	2	12.36h	-	View
43K	0	43	3/2	22.3h	-	View

Legend

Name origin:	English: pot ash; symbol from Latin: kalium, (alkali)
Description:	Soft, waxy, silver-white metal. Eighth most abundant element in the earth's crust (20,900 ppm). Occurs only in compounds.
Discovered by:	Sir Humphrey Davy
Year:	1807
Place:	England
Sources:	Found in minerals like carnallite [(KMgCl3).6H2O] & sylvite (potassium chloride, KCL). Pure metal is produced by the reaction of hot potassium chloride and sodium vapors in a special retort.
Use(s):	Used as potash in making glass & soap. Also as saltpeter, potassium nitrate (KNO3) to make explosives and to color fireworks in mauve. Formerly called kalium (K). Vital to function of nerve and muscle tissures.