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Potassium,  19K
Potassium Spectrum.jpg
Potassium pearls unner paraffin ile. The lairge pearl measures 0.5 cm. Albo: spectral lines o potassium
General properties
Name, seembol potassium, K
Appearance sillery gray
Pronunciation /pˈtæsiəm/ po-TAS-ee-əm
Potassium in the periodic cairt
Hydrogen (diatomic nonmetal)
Helium (noble gas)
Lithium (alkali metal)
Beryllium (alkaline yird metal)
Boron (metalloid)
Carbon (polyatomic nonmetal)
Nitrogen (diatomic nonmetal)
Oxygen (diatomic nonmetal)
Fluorine (diatomic nonmetal)
Neon (noble gas)
Sodium (alkali metal)
Magnesium (alkaline yird metal)
Aluminium (post-transeetion metal)
Silicon (metalloid)
Phosphorus (polyatomic nonmetal)
Sulfur (polyatomic nonmetal)
Chlorine (diatomic nonmetal)
Argon (noble gas)
Potassium (alkali metal)
Calcium (alkaline yird metal)
Scandium (transeetion metal)
Titanium (transeetion metal)
Vanadium (transeetion metal)
Chromium (transeetion metal)
Manganese (transeetion metal)
Airn (transeetion metal)
Cobalt (transeetion metal)
Nickel (transeetion metal)
Capper (transeetion metal)
Zinc (transeetion metal)
Gallium (post-transeetion metal)
Germanium (metalloid)
Arsenic (metalloid)
Selenium (polyatomic nonmetal)
Bromine (diatomic nonmetal)
Krypton (noble gas)
Rubidium (alkali metal)
Strontium (alkaline yird metal)
Yttrium (transeetion metal)
Zirconium (transeetion metal)
Niobium (transeetion metal)
Molybdenum (transeetion metal)
Technetium (transeetion metal)
Ruthenium (transeetion metal)
Rhodium (transeetion metal)
Palladium (transeetion metal)
Siller (transeetion metal)
Cadmium (transeetion metal)
Indium (post-transeetion metal)
Tin (post-transeetion metal)
Antimony (metalloid)
Tellurium (metalloid)
Iodine (diatomic nonmetal)
Xenon (noble gas)
Caesium (alkali metal)
Barium (alkaline yird metal)
Lanthanum (lanthanide)
Cerium (lanthanide)
Praseodymium (lanthanide)
Neodymium (lanthanide)
Promethium (lanthanide)
Samarium (lanthanide)
Europium (lanthanide)
Gadolinium (lanthanide)
Terbium (lanthanide)
Dysprosium (lanthanide)
Holmium (lanthanide)
Erbium (lanthanide)
Thulium (lanthanide)
Ytterbium (lanthanide)
Lutetium (lanthanide)
Hafnium (transeetion metal)
Tantalum (transeetion metal)
Tungsten (transeetion metal)
Rhenium (transeetion metal)
Osmium (transeetion metal)
Iridium (transeetion metal)
Platinum (transeetion metal)
Gold (transeetion metal)
Mercur (transeetion metal)
Thallium (post-transeetion metal)
Leid (post-transeetion metal)
Bismuth (post-transeetion metal)
Polonium (post-transeetion metal)
Astatine (metalloid)
Radon (noble gas)
Francium (alkali metal)
Radium (alkaline yird metal)
Actinium (actinide)
Thorium (actinide)
Protactinium (actinide)
Uranium (actinide)
Neptunium (actinide)
Plutonium (actinide)
Americium (actinide)
Curium (actinide)
Berkelium (actinide)
Californium (actinide)
Einsteinium (actinide)
Fermium (actinide)
Mendelevium (actinide)
Nobelium (actinide)
Lawrencium (actinide)
Rutherfordium (transeetion metal)
Dubnium (transeetion metal)
Seaborgium (transeetion metal)
Bohrium (transeetion metal)
Hassium (transeetion metal)
Meitnerium (unkent chemical properties)
Darmstadtium (unkent chemical properties)
Roentgenium (unkent chemical properties)
Copernicium (transeetion metal)
Ununtrium (unkent chemical properties)
Flerovium (post-transeetion metal)
Ununpentium (unkent chemical properties)
Livermorium (unkent chemical properties)
Ununseptium (unkent chemical properties)
Ununoctium (unkent chemical properties)


Atomic nummer (Z) 19
Group, block group 1 (alkali metals), s-block
Period period 4
Element category   alkali metal
Staundart atomic wicht (±) (Ar) 39.0983(1)
Electron configuration [Ar] 4s1
per shell
2, 8, 8, 1
Pheesical properties
Phase solid
Meltin pynt 336.7 K ​(63.5 °C, ​146.3 °F)
Bylin pynt 1032 K ​(759 °C, ​1398 °F)
Density near r.t. 0.862 g/cm3
when liquid, at m.p. 0.828 g/cm3
Creetical pynt 2223 K, 16[1] MPa
Heat o fusion 2.33 kJ/mol
Heat o vapourisation 76.9 kJ/mol
Molar heat capacity 29.6 J/(mol·K)
Atomic properties
Oxidation states 1, −1 ​strangly basic oxide
Electronegativity Pauling scale: 0.82
Ionisation energies
Atomic radius empirical: 227 pm
Covalent radius 203±12 pm
Van der Waals radius 275 pm
Creestal structur body-centred cubic (bcc)
Body-centered cubic crystal structur for potassium
Speed o soond thin rod 2000 m/s (at 20 °C)
Thermal expansion 83.3 µm/(m·K) (at 25 °C)
Thermal conductivity 102.5 W/(m·K)
Electrical resistivity 72 n Ω·m (at 20 °C)
Magnetic orderin paramagnetic[2]
Young's modulus 3.53 GPa
Shear modulus 1.3 GPa
Bouk modulus 3.1 GPa
Mohs haurdness 0.4
Brinell haurdness 0.363 MPa
CAS Nummer 7440-09-7
Diskivery Humphry Davy (1807)
First isolation Humphry Davy (1807)
Maist stable isotopes o potassium
iso NA hauf-life DM DE (MeV) DP
39K 93.26% 39K is stable wi 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 wi 22 neutrons
· references

Potassium is a chemical element wi seembol K (derived frae Neo-Latin, kalium) an atomic nummer 19. It wis first isolated frae potash, the ess o plants, frae which its name derives. In the periodic cairt, potassium is ane o the alkali metals. Aw o the alkali metals hae a single valence electron in the ooter electron shell, which is easily remuived tae creaut an ion wi a positive chairge – a cation, which combines wi anions tae form sauts. Potassium in naitur occurs anly in ionic sauts. Elemental potassium is a saft sillery-white alkali metal that oxidizes rapidly in air an reacts vigorously wi watter, generatin sufficient heat tae ignite hydrogen emittit in the reaction an burnin wi a lilac-colored flame. It is foond dissolved in sea watter (which is 0.04% potassium bi wecht[3][4]), an is pairt o mony meenerals.

Naiturally occurrin potassium is componed o three isotopes, o which 40
is radioactive. Traces o 40
are foond in aw potassium, an it is the maist common radioisotope in the human bouk.

Potassium is chemically very seemilar tae sodium, the previous element in group 1 o the periodic table. Thay hae a seemilar first ionisation energy, which allows for each atom tae gie up its sole outer electron. That thay are different elements that combine wi the same anions tae mak seemilar salts wis suspected in 1702,[5] an wis proven in 1807 uisin electrolysis.

Maist industrial applications o potassium exploit the heich solubility in watter o potassium compoonds, sic as potassium saips. Hivy crop production rapidly depletes the sile o potassium, an this can be remedied wi agricultural fertilizers containin potassium, accoontin for 95% o global potassium chemical production.[6]

Potassium ions are necessary for the function o aw livin cells. The transfer o potassium ions throu nerve cell membranes is necessary for normal nerve transmission; potassium depletion can result in numerous abnormalities, includin an abnormal hert rhythm an various electrocardiographic (ECG) abnormalities. Fresh fruits an vegetables are guid dietar soorces o potassium. The body responds tae the influx o dietar potassium, which raises serum potassium levels, wi a shift o potassium frae ootside tae inside cells an an increase in potassium excretion bi the neers.

References[eedit | eedit soorce]

  1. Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nt ed.). CRC Press. p. 4.122. ISBN 1439855110. 
  2. 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. 
  3. Webb, D. A. (Aprile 1939). "The Sodium and Potassium Content of Sea Water" (PDF). The Journal of Experimental Biology (2): 183. 
  4. Anthoni, J. (2006). "Detailed composition of seawater at 3.5% salinity". seafriends.org.nz. Retrieved 2011-09-23. 
  5. Marggraf, Andreas Siegmund (1761). Chymische Schriften. p. 167. 
  6. Greenwood, p. 73

Citit soorces

  • Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0-08-037941-9.