Infobox pòtásíọ̀mù

Potassium, 19K
Potassium pearls (in paraffin oil, ~5 mm each)
Potassium
Pípè /pəˈtæsiəm/ (pə-TAS-ee-əm)
Ìhànsójúsilvery gray
Ìwúwo átọ̀mù Ar, std(K)39.0983(1)[1]
Potassium ní orí tábìlì àyè
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
Nọ́mbà átọ̀mù (Z)19
Ẹgbẹ́group 1: H and alkali metals
Àyèàyè 4
Àdìpọ̀Àdìpọ̀-s
Ẹ̀ka ẹ́límẹ́ntì  Alkali metal
Ìtò ẹ̀lẹ́ktrọ́nù[Ar] 4s1
Iye ẹ̀lẹ́ktrọ́nù lórí ìpele kọ̀ọ̀kan2, 8, 8, 1
Àwọn ohun ìní ara
Ìfarahàn at STPsolid
Ìgbà ìyọ́336.7 K ​(63.5 °C, ​146.3 °F)
Ígbà ìhó1032 K ​(759 °C, ​1398 °F)
Kíki (near r.t.)0.862 g/cm3
when liquid (at m.p.)0.828 g/cm3
Critical point2223 K, 16[2] MPa
Heat of fusion2.33 kJ/mol
Heat of 76.9 kJ/mol
Molar heat capacity29.6 J/(mol·K)
Atomic properties
Oxidation states−1, +1 Àdàkọ:Infobox element/symbol-to-oxidation-state/comment
ElectronegativityPauling scale: 0.82
energies
Atomic radiusempirical: 227 pm
Covalent radius203±12 pm
Van der Waals radius275 pm
Color lines in a spectral range
Color lines in a spectral range
Spectral lines of potassium
Other properties
Natural occurrenceprimordial
Crystal structure ​(bcc)
Body-centered cubic crystal structure for potassium
Speed of sound thin rod2000 m/s (at 20 °C)
Thermal expansion83.3 µm/(m·K) (at 25 °C)
Thermal conductivity102.5 W/(m·K)
Electrical resistivity72 n Ω·m (at 20 °C)
Magnetic orderingparamagnetic[3]
Young's modulus3.53 GPa
Shear modulus1.3 GPa
Bulk modulus3.1 GPa
Mohs hardness0.4
Brinell hardness0.363 MPa
CAS Number7440-09-7
History
DiscoveryHumphry Davy (1807)
First isolationHumphry Davy (1807)
Main isotopes of potassium
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct
39K 93.26% 39K is stable with 20 neutrons
40K 0.012% 1.248(3)×109 y β 1.311 40Ca
ε 1.505 40Ar
β+ 1.505 40Ar
41K 6.73% 41K is stable with 22 neutrons
Àdàkọ:Category-inline
| references


  1. Meija, Juris; Coplen, Tyler B.; Berglund, Michael; Brand, Willi A.; De Bièvre, Paul; Gröning, Manfred; Holden, Norman E.; Irrgeher, Johanna et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry 88 (3): 265–91. doi:10.1515/pac-2015-0305. 
  2. Àdàkọ:RubberBible92nd
  3. Magnetic susceptibility of the elements and inorganic compounds, in Àdàkọ:RubberBible86th