ChemiPlus Logo
Dictionary - Training


 General | States | Energies | Oxidation & Electrons | Appearance & Characteristics | Reactions | Other Forms Radius | Conductivity | Abundance


Name: Potassium Symbol: K
Group: Alkali Met. Atomic weight: 39.0983
Density @ 293 K: 0.862 g/cm3 Atomic volume: 45.46 cm3/mol
Group: Alkali Met. discovered: 1807


state (s, l, g): s
melting point: 336.5 K boiling point: 1038.7 K
Heat of fusion: 2.334 kJ/mol Heat of vaporization: 79.870 kJ/mol


1st ionization energy: 418.8 kJ/mole
electronegativity: 0.82 2nd ionization energy: 3051.3 kJ/mole
electron affinity: 48.385 kJ/mole 3rd ionization energy: 4411.3 kJ/mole
Specific heat: 0.75 J/gK heat atomization: 90 kJ/mole atoms

Oxidation & Electrons:

Shells: 2,8,8,1 electron configuration: [Ar] 4s1
minimum oxidation number: 0 maximum oxidation number: 1
min. common oxidation no.: 0 max. common oxidation no.: 1

Appearance & Characteristics:

structure: bcc: body-centered cubic color: silvery-white
uses: fertilizer, low-Na salt toxicity:
hardness: 0.5 mohs characteristics: soft


reaction with air: vigorous, =>KO2
reaction with 6M HCl: vigorous, =>H2, KCl reaction with 6M HCl: vigorous, =>H2, KCl
reaction with 15M HNO3: vigorous, =>H2, NOx, KNO3 reaction with 6M NaOH: vigorous, =>H2, KOH

Other Forms:

number of isotopes: 3 hydride(s): KH
oxide(s): K2O chloride(s): KCl


ionic radius (2- ion): pm ionic radius (1- ion): pm
atomic radius: 227 pm ionic radius (1+ ion): 152 pm
ionic radius (2+ ion): pm ionic radius (3+ ion): pm


thermal conductivity: 102.5 J/m-sec-deg
electrical conductivity: 138.9 1/mohm-cm polarizability: 43.4 A^3


source: Sylvite, carnallite (misc)
rel. abund. solar system: 3.576 log abundance earth's crust: 4.3 log
cost, pure: 85 $/100g cost, bulk: $/100g