Potassi (K)

chemical element with symbol K and atomic number 19

Atomic Number	19
Atomic Weight	39.0983
Rhif màs	39

Group	1
Period	4
Block	s

Proton	19 p⁺
Niwtron	20 n⁰
Electron	19 e^-

Nodwedd Ffisegol

Atomic Radius	220 pm 234 pm
molar volume	45.3 cm³/mol
covalent radius	196 pm 193 pm 207 pm 203 pm
Metallic Radius	203 pm 235 pm
ionic radius	137 pm 138 pm 146 pm 151 pm 155 pm 159 pm 164 pm
Crystal Radius	151 pm 152 pm 160 pm 165 pm 169 pm 173 pm 178 pm
Van der Waals radius	280 pm 275 pm 275 pm 309 pm 381.2 pm
density	0.89 g/cm³ 828 kg/m³

Nodwedd Gemegol

egni

proton affinity
electron affinity	0.50147 eV/particle
ionization energy	4.34066354 eV/particle 31.625 eV/particle 45.8031 eV/particle 60.917 eV/particle 82.66 eV/particle 99.4 eV/particle 117.56 eV/particle 154.87 eV/particle 175.8174 eV/particle 503.67 eV/particle 565.6 eV/particle 631 eV/particle 714.71 eV/particle 786.26 eV/particle 860.92 eV/particle 967.66 eV/particle 1,034.541 eV/particle 4,610.86998 eV/particle 4,934.0482 eV/particle

enthalpy of vaporization	2.33 kJ/mol
enthalpy of fusion	102.5 kJ/mol
standard enthalpy of formation	89 kJ/mol
Electron

plisgyn yr electron	2, 8, 8, 1

valence electron	1 ⓘ

trefn yr electronnau	[Ar] 4s¹ⓘ 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹

Cyflwr ocsidiad	-1, 1
Electronegatifedd	4.34 eV/particle 0.0981896 0.82
Electrophilicity Index	0.7633848415985606 eV/particle
cyflwr sylfaenol mater

cyflwr mater	Solid
gaseous state of matter
Boiling Point	1,032.15 K
Melting Point	336.65 K
critical pressure	16 MPa
critical temperature	2,223.15 K
triple point
appearance
lliw	Silver #ff1493 #8f40d4 #8f40d4
appearance	silvery gray
Mynegrif plygiant
nodwedd ffisegol gwrthrych
Thermal Conductivity	79 W/(m K)
thermal expansion
molar heat capacity	29.6 J/(mol K)
Specific Heat Capacity	0.757 J/(g⋅K)
heat capacity ratio
electrical properties
type	Conductor
dargludedd trydanol	14 MS/m
Gwrthedd	0.00000007000000000002 Ω*m
superconductivity
magnetism
type	paramagnetic
magnetic susceptibility (Mass)	0.0000000067 m³/Kg
magnetic susceptibility (Molar)	0.000000000262 m³/mol
magnetic susceptibility (Volume)	0.00000574
magnetic ordering
Curie temperature
Néel temperature
strwythur
Crystal Structure	Body Centered Cubic (BCC)
lattice constant	5.23 Å
Lattice Angles	π/2, π/2, π/2
nodwedd mecanyddol deunyddiau
hardness	0.363 MPa 0.4 MPa
bulk modulus	3.1 GPa
shear modulus	1.3 GPa
Young's modulus
Poisson's ratio
speed of sound	2,000 m/s
classification
Category	Alkali metals, Alkali metals
CAS Group	IA
IUPAC Group	IA
Glawe Number	10
Mendeleev Number	3
Pettifor Number	10
Geochemical Class	alkali metal
Goldschmidt classification	litophile

other

Gas Basicity
polarizability	289.7 ± 0.3 a₀
C6 Dispersion Coefficient	3,923 a₀ 3,910 a₀
allotrope
Neutron cross section	2.1
Neutron Mass Absorption	0.0018
quantum number	2S1/2
space group	229 (Im_3m)

Isotopes of Potassium

Stable Isotopes	2
Unstable Isotopes	27
Natural Isotopes	3

³¹K

Rhif màs	31
neutron number	12
Relative Atomic Mass	31.03678 ± 0.000322 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes
spin	3/2
nuclear quadrupole moment
dyddiad darganfod	2019
parity	+

decay mode	intensity
3p	100%

³²K

Rhif màs	32
neutron number	13
Relative Atomic Mass	32.023607 ± 0.000429 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes
spin	1
nuclear quadrupole moment
dyddiad darganfod
parity	+

decay mode	intensity
p (proton emission)

³³K

Rhif màs	33
neutron number	14
Relative Atomic Mass	33.008095 ± 0.000215 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes
spin	3/2
nuclear quadrupole moment
dyddiad darganfod
parity	+

decay mode	intensity
p (proton emission)

³⁴K

Rhif màs	34
neutron number	15
Relative Atomic Mass	33.99869 ± 0.00021 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes
spin	1
nuclear quadrupole moment
dyddiad darganfod
parity	+

decay mode	intensity
p (proton emission)

³⁵K

Rhif màs	35
neutron number	16
Relative Atomic Mass	34.988005406 ± 0.00000055 Da
g-factor	0.26133333333333 ± 0.0046666666666667
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	175.2 ± 1.9 ms
spin	3/2
nuclear quadrupole moment
dyddiad darganfod	1976
parity	+

decay mode	intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺ p (β⁺-delayed proton emission)	0.37%

³⁶K

Rhif màs	36
neutron number	17
Relative Atomic Mass	35.981301887 ± 0.000000349 Da
g-factor	0.274 ± 0.0005
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	341 ± 3 ms
spin	2
nuclear quadrupole moment
dyddiad darganfod	1967
parity	+

decay mode	intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺ p (β⁺-delayed proton emission)	0.048%
β⁺α (β⁺-delayed α emission)	0.0034%

³⁷K

Rhif màs	37
neutron number	18
Relative Atomic Mass	36.97337589 ± 0.0000001 Da
g-factor	0.13547333333333 ± 0.00004
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	1.23651 ± 0.00094 s
spin	3/2
nuclear quadrupole moment	0.109 ± 0.004
dyddiad darganfod	1958
parity	+

decay mode	intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

³⁸K

Rhif màs	38
neutron number	19
Relative Atomic Mass	37.969081114 ± 0.000000209 Da
g-factor	0.457 ± 0.002
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	7.651 ± 0.019 m
spin	3
nuclear quadrupole moment
dyddiad darganfod	1937
parity	+

decay mode	intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

³⁹K

Rhif màs	39
neutron number	20
Relative Atomic Mass	38.96370648482 ± 0.00000000489 Da
g-factor	0.26098 ± 0.0000053333333333333
natural abundance	93.2581 ± 0.0044
Dadfeilio ymbelydrol	stable isotope
Hanner oes	Not Radioactive ☢️
spin	3/2
nuclear quadrupole moment	0.0603 ± 0.0006
dyddiad darganfod	1921
parity	+

⁴⁰K

Rhif màs	40
neutron number	21
Relative Atomic Mass	39.963998165 ± 0.00000006 Da
g-factor
natural abundance	0.0117 ± 0.0001
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	1.248 ± 0.003 Gy
spin	4
nuclear quadrupole moment	-0.075 ± 0.0008
dyddiad darganfod	1935
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	89.28%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	10.72%

⁴¹K

Rhif màs	41
neutron number	22
Relative Atomic Mass	40.96182525611 ± 0.00000000403 Da
g-factor	0.143248 ± 0.0000033333333333333
natural abundance	6.7302 ± 0.0044
Dadfeilio ymbelydrol	stable isotope
Hanner oes	Not Radioactive ☢️
spin	3/2
nuclear quadrupole moment	0.0734 ± 0.0007
dyddiad darganfod	1921
parity	+

⁴²K

Rhif màs	42
neutron number	23
Relative Atomic Mass	41.962402305 ± 0.000000113 Da
g-factor	-0.57125 ± 0.0003
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	12.355 ± 0.007 h
spin	2
nuclear quadrupole moment
dyddiad darganfod	1935
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	100%

⁴³K

Rhif màs	43
neutron number	24
Relative Atomic Mass	42.960734701 ± 0.00000044 Da
g-factor	0.10886666666667 ± 0.00053333333333333
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	22.3 ± 0.1 h
spin	3/2
nuclear quadrupole moment
dyddiad darganfod	1949
parity	+

decay mode	intensity
β⁻ (β⁻ decay)	100%

⁴⁴K

Rhif màs	44
neutron number	25
Relative Atomic Mass	43.961586984 ± 0.00000045 Da
g-factor	-0.428 ± 0.002
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	22.13 ± 0.19 m
spin	2
nuclear quadrupole moment
dyddiad darganfod	1954
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	100%

⁴⁵K

Rhif màs	45
neutron number	26
Relative Atomic Mass	44.960691491 ± 0.00000056 Da
g-factor	0.1156 ± 0.00053333333333333
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	17.8 ± 0.6 m
spin	3/2
nuclear quadrupole moment
dyddiad darganfod	1964
parity	+

decay mode	intensity
β⁻ (β⁻ decay)	100%

⁴⁶K

Rhif màs	46
neutron number	27
Relative Atomic Mass	45.961981584 ± 0.00000078 Da
g-factor	-0.5255 ± 0.003
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	96.3 ± 0.08 s
spin	2
nuclear quadrupole moment
dyddiad darganfod	1965
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	100%

⁴⁷K

Rhif màs	47
neutron number	28
Relative Atomic Mass	46.961661612 ± 0.0000015 Da
g-factor	3.866 ± 0.018
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	17.38 ± 0.03 s
spin	1/2
nuclear quadrupole moment	0
dyddiad darganfod	1964
parity	+

decay mode	intensity
β⁻ (β⁻ decay)	100%

⁴⁸K

Rhif màs	48
neutron number	29
Relative Atomic Mass	47.965341184 ± 0.00000083 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	6.83 ± 0.14 s
spin	1
nuclear quadrupole moment
dyddiad darganfod	1972
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	1.14%

⁴⁹K

Rhif màs	49
neutron number	30
Relative Atomic Mass	48.968210753 ± 0.00000086 Da
g-factor	2.6772 ± 0.0016
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	1.26 ± 0.05 s
spin	1/2
nuclear quadrupole moment	0
dyddiad darganfod	1972
parity	+

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	86%

⁵⁰K

Rhif màs	50
neutron number	31
Relative Atomic Mass	49.972380015 ± 0.0000083 Da
g-factor	0
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	472 ± 4 ms
spin	0
nuclear quadrupole moment	0
dyddiad darganfod	1972
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	28.6%
2n (2-neutron emission)

⁵¹K

Rhif màs	51
neutron number	32
Relative Atomic Mass	50.975828664 ± 0.000014 Da
g-factor	0.342 ± 0.0013333333333333
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	365 ± 5 ms
spin	3/2
nuclear quadrupole moment
dyddiad darganfod	1983
parity	+

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	65%
2n (2-neutron emission)

⁵²K

Rhif màs	52
neutron number	33
Relative Atomic Mass	51.981602 ± 0.000036 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	110 ± 4 ms
spin	2
nuclear quadrupole moment
dyddiad darganfod	1983
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	72.2%
2n (2-neutron emission)	2.3%

⁵³K

Rhif màs	53
neutron number	34
Relative Atomic Mass	52.9868 ± 0.00012 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	30 ± 5 ms
spin	3/2
nuclear quadrupole moment
dyddiad darganfod	1983
parity	+

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	64%
2n (2-neutron emission)	10%

⁵⁴K

Rhif màs	54
neutron number	35
Relative Atomic Mass	53.994471 ± 0.000429 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	10 ± 5 ms
spin	2
nuclear quadrupole moment
dyddiad darganfod	1983
parity	-

decay mode	intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)
2n (2-neutron emission)

⁵⁵K

Rhif màs	55
neutron number	36
Relative Atomic Mass	55.000505 ± 0.000537 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes
spin	3/2
nuclear quadrupole moment
dyddiad darganfod	2009
parity	+

decay mode	intensity
β⁻ (β⁻ decay)
β⁻ n (β⁻-delayed neutron emission)
2n (2-neutron emission)

⁵⁶K

Rhif màs	56
neutron number	37
Relative Atomic Mass	56.008567 ± 0.000644 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes
spin	2
nuclear quadrupole moment
dyddiad darganfod	2009
parity	-

decay mode	intensity
β⁻ (β⁻ decay)
β⁻ n (β⁻-delayed neutron emission)
2n (2-neutron emission)

⁵⁷K

Rhif màs	57
neutron number	38
Relative Atomic Mass	57.015169 ± 0.000644 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes
spin	3/2
nuclear quadrupole moment
dyddiad darganfod	2018
parity	+

decay mode	intensity
β⁻ (β⁻ decay)
β⁻ n (β⁻-delayed neutron emission)
2n (2-neutron emission)

⁵⁸K

Rhif màs	58
neutron number	39
Relative Atomic Mass	58.023543 ± 0.000751 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes
spin	2
nuclear quadrupole moment
dyddiad darganfod	2019
parity	-

decay mode	intensity
β⁻ (β⁻ decay)
β⁻ n (β⁻-delayed neutron emission)
2n (2-neutron emission)

⁵⁹K

Rhif màs	59
neutron number	40
Relative Atomic Mass	59.030864 ± 0.000859 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes
spin	3/2
nuclear quadrupole moment
dyddiad darganfod	2018
parity	+

decay mode	intensity
β⁻ (β⁻ decay)
β⁻ n (β⁻-delayed neutron emission)
2n (2-neutron emission)

hanes

darganfyddwr neu ddyfeisiwr	Sir Humphrey Davy
man darganfod	England
dyddiad darganfod	1807
geirdarddiad	English: pot ash; symbol from Latin: kalium, (alkali).
ynganiad	pe-TASS-i-em (Saesneg)

source

Abundance
Abundance in Earth's crust	20,900 mg/kg
natural abundance (cefnfor)	399 mg/L
natural abundance (corff dynol)	0.2 %
natural abundance (Awyrfaen)	0.07 %
natural abundance (Haul)	0.0004 %
Abundance in Universe	0.0003 %

Nuclear Screening Constants

1	s	0.5105
2	p	3.9728
2	s	5.9938
3	p	11.2744
3	s	10.3201
4	s	15.5048

Potassi on ChemicalAid

Australian Educational Vocabulary ID	scot/3560
Brockhaus Enzyklopädie online ID	kalium
ChEBI ID	26216
ChemSpider ID	4575326
Cod yr ATC	A12BA
DSSTOX compound identifier	DTXCID70820696
DSSTox substance ID	DTXSID9049748
Den Store Danske ID	kalium
Dynodwr Drugbank (Alberta)	14500
ECHA Substance Infocard ID	100.028.290
Encyclopedia of China ID (Second Edition)	211021
EuroVoc ID	2568
French Vikidia ID	Potassium
GND	4139553-0
Golden ID	Potassium-GEEZJ
Great Russian Encyclopedia Online ID	2035525
InChI	InChI=1S/K
InChIKey	ZLMJMSJWJFRBEC-UHFFFAOYSA-N
Krugosvet article	nauka_i_tehnika/himiya/KALI.html
Latvian National Encyclopedia Online ID	133174
NDF-RT	N0000146069
Namuwiki ID	칼륨
National Library of Israel J9U ID	987007529540605171
OmegaWiki Defined Meaning	7255
OpenAlex ID	C517785266
Open Food Facts ingredient ID	potassium
PubChem CID	5462222
Rhif Cofrestru CAS	7440-09-7
RxNorm ID	8588
Spanish Vikidia ID	Potasio
Store medisinske leksikon ID	kalium
Store medisinske leksikon ID	kalium_-_fysiologi
Store norske leksikon ID	kalium
UMLS CUI	C0032821
UNII	RWP5GA015D
USGS Thesaurus ID	1543
WordNet 3.1 Synset ID	14674986-n
ZVG number	8150
dynodwr AAT	300212821
dynodwr BnF	121440770
dynodwr Encyclopædia Britannica Online	science/potassium
dynodwr Encyclopædia Universalis	potassium
dynodwr Freebase	/m/025s7j4
dynodwr Gran Enciclopèdia Catalana	0133931
dynodwr HSDB	698
dynodwr ICSC	0716
dynodwr KBpedia	Potassium
dynodwr KEGG	C00238
dynodwr LCAuth	sh85105593
dynodwr MeSH	D011188
dynodwr NDL	00565080
dynodwr NE.se	kalium
dynodwr NKC	ph705338
dynodwr PSH	5746
dynodwr Quora	Potassium
dynodwr Treccani	potassio
dynodwr YSO	11555
dynodwr yn thesawrws y BNCF	22579

Potassi (K)

Nodwedd Ffisegol

Nodwedd Gemegol

other

Isotopes of Potassium

31K

32K

33K

34K

35K

36K

37K

38K

39K

40K

41K

42K

43K

44K

45K

46K

47K

48K

49K

50K

51K

52K

53K

54K

55K

56K

57K

58K

59K

hanes

source

Nuclear Screening Constants

³¹K

³²K

³³K

³⁴K

³⁵K

³⁶K

³⁷K

³⁸K

³⁹K

⁴⁰K

⁴¹K

⁴²K

⁴³K

⁴⁴K

⁴⁵K

⁴⁶K

⁴⁷K

⁴⁸K

⁴⁹K

⁵⁰K

⁵¹K

⁵²K

⁵³K

⁵⁴K

⁵⁵K

⁵⁶K

⁵⁷K

⁵⁸K

⁵⁹K