Chemicool

K

19

39.0983
Potassium
General | States | Energies | Oxidation & Electrons |Appearance & Characteristics
Reactions | Other Forms |Radius | Conductivity | Abundance
Encyclopedia Britannica articles

General
Name Potassium Symbol K
atomic number 19 Atomic weight 39.0983
Density @ 293 K 0.862 g/cm3 Atomic volume 45.46 cm3/mol
Group Alkali Met. discovered 1807

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

Reactions
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
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Other Forms
number of isotopes 3 hydride(s) KH
oxide(s) K2O chloride(s) KCl

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

Abundance
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
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