Template:Infobox potassium

Potassium, 19K
Potassium pearls (in paraffin oil, ~5 mm each)
Potassium
Appearancesilvery white, faint bluish-purple hue when exposed to air
Standard atomic weight Ar°(K)
Potassium in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson
Na

K

Rb
argonpotassiumcalcium
Atomic number (Z)19
Groupgroup 1: hydrogen and alkali metals
Periodperiod 4
Block  s-block
Electron configuration[Ar] 4s1
Electrons per shell2, 8, 8, 1
Physical properties
Phase at STPsolid
Melting point336.7 K ​(63.5 °C, ​146.3 °F)
Boiling point1030.793 K ​(757.643 °C, ​1395.757 °F)[3]
Density (at 20° C)0.8590 g/cm3[4]
when liquid (at m.p.)0.82948 g/cm3[3]
Critical point2223 K, 16 MPa[5]
Heat of fusion2.33 kJ/mol
Heat of vaporization76.9 kJ/mol
Molar heat capacity29.6 J/(mol·K)
Atomic properties
Oxidation statescommon: +1
−1?
ElectronegativityPauling scale: 0.82
Ionization energies
  • 1st: 418.8 kJ/mol
  • 2nd: 3052 kJ/mol
  • 3rd: 4420 kJ/mol
  • (more)
Atomic radiusempirical: 227 pm
Covalent radius203±12 pm
Van der Waals radius275 pm
Color lines in a spectral range
Spectral lines of potassium
Other properties
Natural occurrenceprimordial
Crystal structurebody-centered cubic (bcc) (cI2)
Lattice constant
Body-centered cubic crystal structure for potassium
a = 532.69 pm (at 20 °C)[4]
Thermal expansion77.37×10−6/K (at 20 °C)[4]
Thermal conductivity102.5 W/(m⋅K)
Electrical resistivity72 nΩ⋅m (at 20 °C)
Magnetic orderingparamagnetic[6]
Molar magnetic susceptibility+20.8×10−6 cm3/mol (298 K)[7]
Young's modulus3.53 GPa
Shear modulus1.3 GPa
Bulk modulus3.1 GPa
Speed of sound thin rod2000 m/s (at 20 °C)
Mohs hardness0.4
Brinell hardness0.363 MPa
CAS Number7440-09-7
History
Discovery and first isolationHumphry Davy (1807)
Symbol"K": from New Latin kalium
Isotopes of potassium
Main isotopes Decay
abun­dance half-life (t1/2) mode pro­duct
39K 93.3% stable
40K 0.0120% 1.248×109 y β 40Ca
ε 40Ar
β+ 40Ar
41K 6.73% stable
 Category: Potassium
| references
K · Potassium
Ar ←

ibox Ar

iso
19
K  [e]
IB-K [e]
IBisos [e]
→ Ca

ibox Ca

indexes by PT (page)
child table, as reused in {IB-K}
Main isotopes of potassium
Main isotopes Decay
abun­dance half-life (t1/2) mode pro­duct
39K 93.3% stable
40K 0.0120% 1.248×109 y β 40Ca
ε 40Ar
β+ 40Ar
41K 6.73% stable
Data sets read by {{Infobox element}}
Name and identifiers
Symbol etymology (11 non-trivial)
Top image (caption, alt)
Pronunciation
Allotropes (overview)
Group (overview)
Period (overview)
Block (overview)
Natural occurrence
Phase at STP
Oxidation states
Spectral lines image
Electron configuration (cmt, ref)
Isotopes
Standard atomic weight
  most stable isotope
Wikidata
Wikidata *
* Not used in {{Infobox element}} (2023-01-01)
See also {{Index of data sets}} · Cat:data sets (46) · (this table: )

References

  1. ^ "Standard Atomic Weights: Potassium". CIAAW. 1979.
  2. ^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
  3. ^ a b Aitken, F.; Volino, F. (January 2022). "New equations of state describing both the dynamic viscosity and self-diffusion coefficient for potassium and thallium in their fluid phases". Physics of Fluids. 34 (1): 017112. doi:10.1063/5.0079944.
  4. ^ a b c Arblaster, John W. (2018). Selected Values of the Crystallographic Properties of Elements. Materials Park, Ohio: ASM International. ISBN 978-1-62708-155-9.
  5. ^ Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nd ed.). Boca Raton, FL: CRC Press. p. 4.122. ISBN 1-4398-5511-0.
  6. ^ Magnetic susceptibility of the elements and inorganic compounds, in Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.
  7. ^ Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.

One of these is a named reference. It may be cited in the containing article as

  • <ref name="CIAAW2013" /> for the source Atomic weights of the elements 2013 (from subtemplates used by {{Infobox element}})