Potassium

Potassium Element Properties

p18
Ar
Argon
s19
K
Potassium
s20
Ca
Calcium
General
NamePotassium
SymbolK
Number19
Group Number1
GroupAlkali metals
Blocks
Density0.862 g/cm3
Atomic Weight39.0983 g/mol
Atomic Volume45.46 cm3/mol
Discover1807


States
StateSolid
Melting Point336.53 K
Boiling Point1032 K
Triple Point336.35 K
Critical PointNil
Heat of Fusion2.334 kJ/mol
Heat of Vaporization79.870 kJ/mol


Energies
First Ionization Energy418.8 kJ/mole
Second Ionization Energy3051.3 kJ/mole
Third Ionization Energy4411.3 kJ/mole
Electronegativity0.82
Electron Affinity48.385 kJ/mole
Specific Heat0.75 J/gK
Heat Atomization90 kJ/mole atoms


Oxidation and Electrons
Shells2,8,8,1
Electron Configuration[Ar] 4s1
Minimum Oxidation Number0
Maximum Oxidation Number1
Minimum Common Oxidation Number0
Maximum Common Oxidation Number1


Appearance and Characteristics
Crystal Structurecubic body centered
Characteristicssoft
Colorsilvery-white
Usesfertilizer, low-Na salt
Hardness0.5 mohs
ToxicityNone


Reactions
Reaction with Airvigorous, =>KO2
Reaction with 6M HClvigorous, =>H2, KCl
Reaction with 15M HNO3vigorous, =>H2, NOx, KNO3
Reaction with 6M NaOHvigorous, =>H2, KOH


Other Forms
Number of Isotopes3
HydrideKH
OxideK2O
ChlorideKCl


Radius
Atomic Radius227 pm
Ionic Radius (1+ ion)152 pm
Ionic Radius (1- ion)Nil
Ionic Radius (2+ ion)Nil
Ionic Radius (2- ion)Nil
Ionic Radius (3+ ion)Nil


Conductivity
Thermal Conductivity102.5 J/m-sec-deg
Electrical Conductivity138.9 1/mohm-cm
Polarizability43.4 A3


Abundance
SourceSylvite, carnallite (misc)
Relation Abundance Solar System3.576 log
Abundance Earth's Crust4.3 log


p18
Ar
Argon
s19
K
Potassium
s20
Ca
Calcium