Crom (Cr)

chemical element with symbol Cr and atomic number 24

Atomic Number	24
Atomic Weight	51.9961
Rhif màs	52

Group	6
Period	4
Block	d

Proton	24 p⁺
Niwtron	28 n⁰
Electron	24 e^-

Nodwedd Ffisegol

Atomic Radius	140 pm 233 pm
molar volume	7.23 cm³/mol
covalent radius	122 pm 111 pm 103 pm 140 pm 139 pm
Metallic Radius	119 pm 128 pm
ionic radius	73 pm 80 pm 61.5 pm 41 pm 55 pm 34.5 pm 49 pm 57 pm 26 pm 44 pm
Crystal Radius	87 pm 94 pm 75.5 pm 55 pm 69 pm 48.5 pm 63 pm 71 pm 40 pm 58 pm
Van der Waals radius	205 pm 206 pm 225 pm 302.3 pm
density	7.15 g/cm³ 6,300 kg/m³

Nodwedd Gemegol

{ERROR}

egni

proton affinity	791.3 kJ/mol
electron affinity	0.666 eV/particle
ionization energy	6.76651 eV/particle 16.486305 eV/particle 30.96 eV/particle 49.16 eV/particle 69.46 eV/particle 90.635 eV/particle 160.29 eV/particle 184.76 eV/particle 209.54 eV/particle 244.52 eV/particle 270.8 eV/particle 296.74 eV/particle 354.66 eV/particle 384.163 eV/particle 1,011.62 eV/particle 1,097.2 eV/particle 1,188 eV/particle 1,294.8 eV/particle 1,394.5 eV/particle 1,495.1 eV/particle 1,634 eV/particle 1,721.183 eV/particle 7,481.8625 eV/particle 7,894.799 eV/particle

enthalpy of vaporization	342 kJ/mol
enthalpy of fusion	21 kJ/mol
standard enthalpy of formation	397.48 kJ/mol
Electron

plisgyn yr electron	2, 8, 13, 1

valence electron	1 ⓘ

trefn yr electronnau	[Ar] 3d⁵ 4s¹ⓘ 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹

Cyflwr ocsidiad	-4, -2, -1, 0, 1, 2, 3, 4, 5, 6
Electronegatifedd	9.77 eV/particle 0.1313053 1.66
Electrophilicity Index	1.1319177597467263 eV/particle
cyflwr sylfaenol mater

cyflwr mater
gaseous state of matter
Boiling Point	2,944.15 K
Melting Point	2,180.15 K
critical pressure
critical temperature
triple point
appearance
lliw	Black #808090 #8a99c7 #8a99c7
appearance	silvery metallic
Mynegrif plygiant
nodwedd ffisegol gwrthrych
Thermal Conductivity	93.9 W/(m K)
thermal expansion	0.0000049 1/K
molar heat capacity	23.35 J/(mol K)
Specific Heat Capacity	0.449 J/(g⋅K)
heat capacity ratio
electrical properties
type	Conductor
dargludedd trydanol	7.9 MS/m
Gwrthedd	0.00000013 Ω*m
superconductivity
magnetism
type	antiferromagnetic
magnetic susceptibility (Mass)	0.0000000445 m³/Kg
magnetic susceptibility (Molar)	0.000000002314 m³/mol
magnetic susceptibility (Volume)	0.0003177
magnetic ordering
Curie temperature
Néel temperature	393 K
strwythur
Crystal Structure	{ERROR}
lattice constant	2.88 Å
Lattice Angles	π/2, π/2, π/2
nodwedd mecanyddol deunyddiau
hardness	1,120 MPa 8.5 MPa 1,060 MPa
bulk modulus	160 GPa
shear modulus	115 GPa
Young's modulus	279 GPa
Poisson's ratio	0.21
speed of sound	5,940 m/s
classification
Category	Actinides, Transition metals
CAS Group	VIA
IUPAC Group	VIB
Glawe Number	55
Mendeleev Number	51
Pettifor Number	57
Geochemical Class	first series transition metal
Goldschmidt classification	litophile

other

Gas Basicity	768.4 kJ/mol
polarizability	83 ± 12 a₀
C6 Dispersion Coefficient	602 a₀ 709 a₀
allotrope
Neutron cross section	3.1
Neutron Mass Absorption	0.0021
quantum number	7S3
space group	229 (Im_3m)

Isotopes of Chromium

Stable Isotopes	3
Unstable Isotopes	27
Natural Isotopes	4

⁴¹Cr

Rhif màs	41
neutron number	17
Relative Atomic Mass	41.021911 ± 0.000429 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)

⁴²Cr

Rhif màs	42
neutron number	18
Relative Atomic Mass	42.007579 ± 0.000322 Da
g-factor	0
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	13.3 ± 1 ms
spin	0
nuclear quadrupole moment	0
dyddiad darganfod	1996
parity	+

decay mode	intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺ p (β⁺-delayed proton emission)	94.4%
2p (2-proton emission)

⁴³Cr

Rhif màs	43
neutron number	19
Relative Atomic Mass	42.997885 ± 0.000215 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	21.1 ± 0.3 ms
spin	3/2
nuclear quadrupole moment
dyddiad darganfod	1992
parity	+

decay mode	intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺ p (β⁺-delayed proton emission)	79.3%
2p (2-proton emission)	11.6%
3p	0.13%
β⁺α (β⁺-delayed α emission)

⁴⁴Cr

Rhif màs	44
neutron number	20
Relative Atomic Mass	43.985591 ± 0.000055 Da
g-factor	0
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	42.8 ± 0.6 ms
spin	0
nuclear quadrupole moment	0
dyddiad darganfod	1987
parity	+

decay mode	intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺ p (β⁺-delayed proton emission)	12%

⁴⁵Cr

Rhif màs	45
neutron number	21
Relative Atomic Mass	44.97905 ± 0.000038 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	60.9 ± 0.4 ms
spin	7/2
nuclear quadrupole moment
dyddiad darganfod	1974
parity	-

decay mode	intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺ p (β⁺-delayed proton emission)	34.4%

⁴⁶Cr

Rhif màs	46
neutron number	22
Relative Atomic Mass	45.968360969 ± 0.000012295 Da
g-factor	0
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	224.3 ± 1.3 ms
spin	0
nuclear quadrupole moment	0
dyddiad darganfod	1972
parity	+

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

⁴⁷Cr

Rhif màs	47
neutron number	23
Relative Atomic Mass	46.962894995 ± 0.000005578 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	461.6 ± 1.5 ms
spin	3/2
nuclear quadrupole moment
dyddiad darganfod	1972
parity	-

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

⁴⁸Cr

Rhif màs	48
neutron number	24
Relative Atomic Mass	47.954029431 ± 0.000007848 Da
g-factor	0
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	21.56 ± 0.03 h
spin	0
nuclear quadrupole moment	0
dyddiad darganfod	1952
parity	+

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

⁴⁹Cr

Rhif màs	49
neutron number	25
Relative Atomic Mass	48.95133372 ± 0.000002363 Da
g-factor	0.1904 ± 0.0012
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	42.3 ± 0.1 m
spin	5/2
nuclear quadrupole moment
dyddiad darganfod	1942
parity	-

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

⁵⁰Cr

Rhif màs	50
neutron number	26
Relative Atomic Mass	49.946042209 ± 0.0000001 Da
g-factor	0
natural abundance	4.345 ± 0.013
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes
spin	0
nuclear quadrupole moment	0
dyddiad darganfod	1930
parity	+

decay mode	intensity
2β⁺ (double β⁺ decay)

⁵¹Cr

Rhif màs	51
neutron number	27
Relative Atomic Mass	50.944765388 ± 0.000000178 Da
g-factor	0.26685714285714 ± 0.0014285714285714
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	27.7015 ± 0.0011 d
spin	7/2
nuclear quadrupole moment
dyddiad darganfod	1940
parity	-

decay mode	intensity
ϵ (electron capture)	100%

⁵²Cr

Rhif màs	52
neutron number	28
Relative Atomic Mass	51.940504714 ± 0.00000012 Da
g-factor	0
natural abundance	83.789 ± 0.018
Dadfeilio ymbelydrol	stable isotope
Hanner oes	Not Radioactive ☢️
spin	0
nuclear quadrupole moment	0
dyddiad darganfod	1923
parity	+

⁵³Cr

Rhif màs	53
neutron number	29
Relative Atomic Mass	52.940646304 ± 0.000000124 Da
g-factor
natural abundance	9.501 ± 0.017
Dadfeilio ymbelydrol	stable isotope
Hanner oes	Not Radioactive ☢️
spin	3/2
nuclear quadrupole moment	-0.15 ± 0.05
dyddiad darganfod	1930
parity	-

⁵⁴Cr

Rhif màs	54
neutron number	30
Relative Atomic Mass	53.938877359 ± 0.000000142 Da
g-factor	0
natural abundance	2.365 ± 0.007
Dadfeilio ymbelydrol	stable isotope
Hanner oes	Not Radioactive ☢️
spin	0
nuclear quadrupole moment	0
dyddiad darganfod	1930
parity	+

⁵⁵Cr

Rhif màs	55
neutron number	31
Relative Atomic Mass	54.940836637 ± 0.000000245 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	3.497 ± 0.003 m
spin	3/2
nuclear quadrupole moment
dyddiad darganfod	1952
parity	-

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

⁵⁶Cr

Rhif màs	56
neutron number	32
Relative Atomic Mass	55.940648977 ± 0.00000062 Da
g-factor	0
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	5.94 ± 0.1 m
spin	0
nuclear quadrupole moment	0
dyddiad darganfod	1960
parity	+

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

⁵⁷Cr

Rhif màs	57
neutron number	33
Relative Atomic Mass	56.943612112 ± 0.000002 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	21.1 ± 1 s
spin	3/2
nuclear quadrupole moment
dyddiad darganfod	1978
parity

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

⁵⁸Cr

Rhif màs	58
neutron number	34
Relative Atomic Mass	57.944184501 ± 0.0000032 Da
g-factor	0
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	7 ± 0.3 s
spin	0
nuclear quadrupole moment	0
dyddiad darganfod	1980
parity	+

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

⁵⁹Cr

Rhif màs	59
neutron number	35
Relative Atomic Mass	58.948345426 ± 0.00000072 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	1,050 ± 90 ms
spin	1/2
nuclear quadrupole moment	0
dyddiad darganfod	1980
parity	-

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

⁶⁰Cr

Rhif màs	60
neutron number	36
Relative Atomic Mass	59.949641656 ± 0.0000012 Da
g-factor	0
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	490 ± 10 ms
spin	0
nuclear quadrupole moment	0
dyddiad darganfod	1980
parity	+

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

⁶¹Cr

Rhif màs	61
neutron number	37
Relative Atomic Mass	60.95437813 ± 0.000002 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	243 ± 9 ms
spin	5/2
nuclear quadrupole moment
dyddiad darganfod	1985
parity	-

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

⁶²Cr

Rhif màs	62
neutron number	38
Relative Atomic Mass	61.95614292 ± 0.0000037 Da
g-factor	0
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	206 ± 12 ms
spin	0
nuclear quadrupole moment	0
dyddiad darganfod	1985
parity	+

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

⁶³Cr

Rhif màs	63
neutron number	39
Relative Atomic Mass	62.961161 ± 0.000078 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	129 ± 2 ms
spin	1/2
nuclear quadrupole moment	0
dyddiad darganfod	1992
parity	-

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

⁶⁴Cr

Rhif màs	64
neutron number	40
Relative Atomic Mass	63.963886 ± 0.000322 Da
g-factor	0
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	43 ± 1 ms
spin	0
nuclear quadrupole moment	0
dyddiad darganfod	1992
parity	+

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

⁶⁵Cr

Rhif màs	65
neutron number	41
Relative Atomic Mass	64.969608 ± 0.000215 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	27.5 ± 2.1 ms
spin	1/2
nuclear quadrupole moment	0
dyddiad darganfod	1997
parity	-

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

⁶⁶Cr

Rhif màs	66
neutron number	42
Relative Atomic Mass	65.973011 ± 0.000322 Da
g-factor	0
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes	23.8 ± 1.8 ms
spin	0
nuclear quadrupole moment	0
dyddiad darganfod	1997
parity	+

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

⁶⁷Cr

Rhif màs	67
neutron number	43
Relative Atomic Mass	66.979313 ± 0.000429 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes
spin	1/2
nuclear quadrupole moment	0
dyddiad darganfod	1997
parity	-

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

⁶⁸Cr

Rhif màs	68
neutron number	44
Relative Atomic Mass	67.983156 ± 0.000537 Da
g-factor	0
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes
spin	0
nuclear quadrupole moment	0
dyddiad darganfod	2009
parity	+

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

⁶⁹Cr

Rhif màs	69
neutron number	45
Relative Atomic Mass	68.989662 ± 0.000537 Da
g-factor
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes
spin	7/2
nuclear quadrupole moment
dyddiad darganfod	2013
parity	+

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

⁷⁰Cr

Rhif màs	70
neutron number	46
Relative Atomic Mass	69.993945 ± 0.000644 Da
g-factor	0
natural abundance
Dadfeilio ymbelydrol	☢️ elfen ymbelydrol
Hanner oes
spin	0
nuclear quadrupole moment	0
dyddiad darganfod	2013
parity	+

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

hanes

darganfyddwr neu ddyfeisiwr	Louis Vauquelin
man darganfod	France
dyddiad darganfod	1797
geirdarddiad	Greek: chrôma (color).
ynganiad	KROH-mi-em (Saesneg)

source

Abundance
Abundance in Earth's crust	102 mg/kg
natural abundance (cefnfor)	0.0003 mg/L
natural abundance (corff dynol)	0.000003 %
natural abundance (Awyrfaen)	0.3 %
natural abundance (Haul)	0.002 %
Abundance in Universe	0.0015 %

Nuclear Screening Constants

1	s	0.5862
2	p	3.9248
2	s	7.0162
3	d	14.2434
3	p	12.534
3	s	11.6322
4	s	18.8668

Crom on ChemicalAid

Crom (Cr)

Nodwedd Ffisegol

Nodwedd Gemegol

other

Isotopes of Chromium

41Cr

42Cr

43Cr

44Cr

45Cr

46Cr

47Cr

48Cr

49Cr

50Cr

51Cr

52Cr

53Cr

54Cr

55Cr

56Cr

57Cr

58Cr

59Cr

60Cr

61Cr

62Cr

63Cr

64Cr

65Cr

66Cr

67Cr

68Cr

69Cr

70Cr

hanes

source

Nuclear Screening Constants

⁴¹Cr

⁴²Cr

⁴³Cr

⁴⁴Cr

⁴⁵Cr

⁴⁶Cr

⁴⁷Cr

⁴⁸Cr

⁴⁹Cr

⁵⁰Cr

⁵¹Cr

⁵²Cr

⁵³Cr

⁵⁴Cr

⁵⁵Cr

⁵⁶Cr

⁵⁷Cr

⁵⁸Cr

⁵⁹Cr

⁶⁰Cr

⁶¹Cr

⁶²Cr

⁶³Cr

⁶⁴Cr

⁶⁵Cr

⁶⁶Cr

⁶⁷Cr

⁶⁸Cr

⁶⁹Cr

⁷⁰Cr