Template:Infobox potassium

Potassium, ₁₉K

Potassium pearls (in paraffin oil, ~5 mm each)
Potassium
Pronunciation	/pəˈtæsiəm/ ​(pə-TASS-ee-əm)
Appearance	silvery gray
Standard atomic weight Ar, std(K)	39.0983(1)
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 argon ← potassium → calcium
Atomic number (Z)	19
Group	group 1: hydrogen and alkali metals
Period	period 4
Block	s-block
Element category	s-block
Electron configuration	[Ar] 4s1
Electrons per shell	2, 8, 8, 1
Physical properties
Phase at STP	solid
Melting point	336.7 K ​(63.5 °C, ​146.3 °F)
Boiling point	1032 K ​(759 °C, ​1398 °F)
Density (near r.t.)	0.89 g/cm3
when liquid (at m.p.)	0.828 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 (a strongly basic oxide)
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
Spectral lines of potassium
Other properties
Natural occurrence	primordial
Crystal structure	​body-centered cubic (bcc)
Speed of sound 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 nΩ·m (at 20 °C)
Magnetic ordering	paramagnetic
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
Mohs hardness	0.4
Brinell hardness	0.363 MPa
CAS Number	7440-09-7
History
Discovery and first isolation	Humphry Davy (1807)
Main isotopes of potassium
Iso­tope Abun­dance Physics:Half-life (t1/2) Decay mode Pro­duct 39K 93.258% stable 40K 0.012% 1.248×109 y β− 40Ca ε 40Ar β+ 40Ar 41K 6.730% stable

K data m.p. cat
	in	calc from C	diff	report	ref
C	63.5	—	—
K	336.7	336.6	0.1
F	146.3	146.3	0
max precision	1
WD
input	C: 63.5, K: 336.7, F: 146.3
comment

K data b.p. cat
	in	calc from C	diff	report	ref
C	759	—	—
K	1032	1032	0
F	1398	1398	0
max precision	0
WD
input	C: 759, K: 1032, F: 1398
comment

PTChemistry:potassium

Ar ← i'box Ar	iso19K  infobox  isobox	→ Ca i'box Ca
Commons  Wikidata:Q703  Wiktionary Indexes in PT: § below · Page

[]  Data sets read by {{Infobox element}}
Name and identifiers
Top image (caption, alt)
Pronunciation
Category (enwiki)
Standard atomic weight
most stable isotope
Natural occurrence
Phase at STP
Chemistry:Oxidation states
Spectral lines image
Physics:Electron configuration (cmt, ref)
Term symbol * (cmt, ref)
Wikidata *
* Not used in {{Infobox element}} (2019-02-03) See also {{Infobox element/symbol-to--navbox}}

References

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