Potasyo

Potassium, ₁₉K

Potassium pearls (in paraffin oil, ~5 mm each)
Potassium
Bigkas	/pəˈtæsiəm/ ​(pə-TASS-ee-əm)
Appearance	silvery white, faint bluish-purple hue when exposed to air
Standard atomic weight Ar°(K)
	39.0983±0.0001 39.098±0.001 (pinaikli)
Potassium sa talahanayang peryodiko
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 argon ← potassium → calcium
Atomikong bilang (Z)	19
Group	1
Period	4
Block	s-block
Electron configuration	[Ar] 4s1
Electrons per shell	2, 8, 8, 1
Physical properties
Phase at STP	solido
Melting point	336.7 K ​(63.5 °C, ​146.3 °F)
Boiling point	1030.793 K ​(757.643 °C, ​1395.757 °F)
Density (at 20° C)	0.8590 g/cm3
when liquid (at m.p.)	0.82948 g/cm3
Critical point	2223 K, 16 MPa
Heat of fusion	2.33 kJ/mol
Heat of vaporization	76.9 kJ/mol
Molar heat capacity	29.6 J/(mol·K)
Atomic properties
Oxidation states	−1, +1 (isang matapang na panimulang oksido)
Electronegativity	Pauling scale: 0.82
Ionization energies	1st: 418.8 kJ/mol 2nd: 3052 kJ/mol 3rd: 4420 kJ/mol (more)
Atomic radius	empirical: 227 pm
Covalent radius	203±12 pm
Van der Waals radius	275 pm
Mga linyang espektral ng potassium
Other properties
Natural occurrence	primordiyal
Crystal structure	​body-centered cubic (bcc) (cI2)
Lattice constant	a = 532.69 pm (at 20 °C)
Thermal expansion	77.37×10−6/K (at 20 °C)
Thermal conductivity	102.5 W/(m⋅K)
Electrical resistivity	72 nΩ⋅m (at 20 °C)
Magnetic ordering	paramagnetic
Molar magnetic susceptibility	+20.8×10−6 cm3/mol (298 K)
Young's modulus	3.53 GPa
Shear modulus	1.3 GPa
Bulk modulus	3.1 GPa
Speed of sound thin rod	2000 m/s (at 20 °C)
Mohs hardness	0.4
Brinell hardness	0.363 MPa
CAS Number	7440-09-7
History
Discovery and first isolation	Humphry Davy (1807)
Symbol	"K": mula sa Bagong Latin na 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

Ang potasyo o potasyum (Kastila: potasio, Ingles: potassium, may sagisag na K na mula sa kalium [huwag ikalito sa kalyo], may atomikong bilang na 19, atomikong timbang na 39.102, punto ng pagkatunaw na 63.65 °C, punto ng pagkulong 774 °C, espesipikong grabidad na 0.862, at balensyang 1) ay isang elementong metalikong ginagamit sa paggawa ng mga asing kailangang maisangkap sa abono at sabon. Katangian nito ang pagiging katulad ng pilak, may kalambutan, at madaling sumabog. Si Humphry Davy ang nakatuklas nito noong 1807.