Symbol K Atomic radius: pm 227 Fusion: kJ/Mole 2.33
Name Potassium Ionic radius: pm (+1)151 Boiling point: C 759
Atomic number 19 Electron affinity 0.50 Melting point: C 64
Atomic weight 39.10 1st  ion potential 4.34 Specific Heat Cap: J/(g K) 0.76
Classification Alkali metal Natural form Solid Thermal Cond: W/(cm K) 1.03
Configuration [Ar]4s1 Crystal structure BCC Electrical Cond 0.139
Oxidation states 1 Density 0.89 Abundance: mg/kg-crust 20,900
Electronegativity 0.82 Vaporization: kJ/Mole 77.5    
Potassium was the first metal to be isolated by electrolysis, by Sir Humphrey Davy, when he discovered the element in 1807. Uses - fertilizer, low sodium salt, glass, soap, detergents, fireworks