Krom (Cr)

chemical element with symbol Cr and atomic number 24

Atomic Number	24
Atomic Weight	51.9961
mass number	52

Group	6
Period	4
Block	d

proton	24 p⁺
neutron	28 n⁰
electron	24 e^-

Physical Property

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

Chemical Property

{ERROR}

energy

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

electron shell	2, 8, 13, 1

valence electron	1 ⓘ

electron configuration	[Ar] 3d⁵ 4s¹ⓘ 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹

oxidation number	-4, -2, -1, 0, 1, 2, 3, 4, 5, 6
electronegativity	9,77 eV/particle 0.1313053 1.66
Electrophilicity Index	1,1319177597467263 eV/particle
fundamental state of matter

phase of matter
gaseous state of matter
Boiling Point	2 944,15 K
Melting Point	2 180,15 K
critical pressure
critical temperature
triple point
appearance
color	Black #808090 #8a99c7 #8a99c7
appearance	silvery metallic
refractive index
thermodynamic material property
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
electrical conductivity	7,9 MS/m
electrical resistivity	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
structure
Crystal Structure	{ERROR}
lattice constant	2,88 Å
Lattice Angles	π/2, π/2, π/2
mechanical property
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

mass number	41
neutron number	17
Relative Atomic Mass	41,021911 ± 0,000429 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life
spin	3/2
nuclear quadrupole moment
time of discovery or invention
parity	+

decay mode	intensity
p (proton emission)

⁴²Cr

mass number	42
neutron number	18
Relative Atomic Mass	42,007579 ± 0,000322 Da
g-factor	0
natural abundance
radioactivity	☢️ radioactive element
half-life	13,3 ± 1 ms
spin	0
nuclear quadrupole moment	0
time of discovery or invention	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

mass number	43
neutron number	19
Relative Atomic Mass	42,997885 ± 0,000215 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	21,1 ± 0,3 ms
spin	3/2
nuclear quadrupole moment
time of discovery or invention	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

mass number	44
neutron number	20
Relative Atomic Mass	43,985591 ± 0,000055 Da
g-factor	0
natural abundance
radioactivity	☢️ radioactive element
half-life	42,8 ± 0,6 ms
spin	0
nuclear quadrupole moment	0
time of discovery or invention	1987
parity	+

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

⁴⁵Cr

mass number	45
neutron number	21
Relative Atomic Mass	44,97905 ± 0,000038 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	60,9 ± 0,4 ms
spin	7/2
nuclear quadrupole moment
time of discovery or invention	1974
parity	-

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

⁴⁶Cr

mass number	46
neutron number	22
Relative Atomic Mass	45,968360969 ± 0,000012295 Da
g-factor	0
natural abundance
radioactivity	☢️ radioactive element
half-life	224,3 ± 1,3 ms
spin	0
nuclear quadrupole moment	0
time of discovery or invention	1972
parity	+

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

⁴⁷Cr

mass number	47
neutron number	23
Relative Atomic Mass	46,962894995 ± 0,000005578 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	461,6 ± 1,5 ms
spin	3/2
nuclear quadrupole moment
time of discovery or invention	1972
parity	-

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

⁴⁸Cr

mass number	48
neutron number	24
Relative Atomic Mass	47,954029431 ± 0,000007848 Da
g-factor	0
natural abundance
radioactivity	☢️ radioactive element
half-life	21,56 ± 0,03 h
spin	0
nuclear quadrupole moment	0
time of discovery or invention	1952
parity	+

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

⁴⁹Cr

mass number	49
neutron number	25
Relative Atomic Mass	48,95133372 ± 0,000002363 Da
g-factor	0,1904 ± 0,0012
natural abundance
radioactivity	☢️ radioactive element
half-life	42,3 ± 0,1 m
spin	5/2
nuclear quadrupole moment
time of discovery or invention	1942
parity	-

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

⁵⁰Cr

mass number	50
neutron number	26
Relative Atomic Mass	49,946042209 ± 0,0000001 Da
g-factor	0
natural abundance	4,345 ± 0,013
radioactivity	☢️ radioactive element
half-life
spin	0
nuclear quadrupole moment	0
time of discovery or invention	1930
parity	+

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

⁵¹Cr

mass number	51
neutron number	27
Relative Atomic Mass	50,944765388 ± 0,000000178 Da
g-factor	0,26685714285714 ± 0,0014285714285714
natural abundance
radioactivity	☢️ radioactive element
half-life	27,7015 ± 0,0011 d
spin	7/2
nuclear quadrupole moment
time of discovery or invention	1940
parity	-

decay mode	intensity
ϵ (electron capture)	100%

⁵²Cr

mass number	52
neutron number	28
Relative Atomic Mass	51,940504714 ± 0,00000012 Da
g-factor	0
natural abundance	83,789 ± 0,018
radioactivity	stable isotope
half-life	Not Radioactive ☢️
spin	0
nuclear quadrupole moment	0
time of discovery or invention	1923
parity	+

⁵³Cr

mass number	53
neutron number	29
Relative Atomic Mass	52,940646304 ± 0,000000124 Da
g-factor
natural abundance	9,501 ± 0,017
radioactivity	stable isotope
half-life	Not Radioactive ☢️
spin	3/2
nuclear quadrupole moment	−0,15 ± 0,05
time of discovery or invention	1930
parity	-

⁵⁴Cr

mass number	54
neutron number	30
Relative Atomic Mass	53,938877359 ± 0,000000142 Da
g-factor	0
natural abundance	2,365 ± 0,007
radioactivity	stable isotope
half-life	Not Radioactive ☢️
spin	0
nuclear quadrupole moment	0
time of discovery or invention	1930
parity	+

⁵⁵Cr

mass number	55
neutron number	31
Relative Atomic Mass	54,940836637 ± 0,000000245 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	3,497 ± 0,003 m
spin	3/2
nuclear quadrupole moment
time of discovery or invention	1952
parity	-

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

⁵⁶Cr

mass number	56
neutron number	32
Relative Atomic Mass	55,940648977 ± 0,00000062 Da
g-factor	0
natural abundance
radioactivity	☢️ radioactive element
half-life	5,94 ± 0,1 m
spin	0
nuclear quadrupole moment	0
time of discovery or invention	1960
parity	+

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

⁵⁷Cr

mass number	57
neutron number	33
Relative Atomic Mass	56,943612112 ± 0,000002 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	21,1 ± 1 s
spin	3/2
nuclear quadrupole moment
time of discovery or invention	1978
parity

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

⁵⁸Cr

mass number	58
neutron number	34
Relative Atomic Mass	57,944184501 ± 0,0000032 Da
g-factor	0
natural abundance
radioactivity	☢️ radioactive element
half-life	7 ± 0,3 s
spin	0
nuclear quadrupole moment	0
time of discovery or invention	1980
parity	+

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

⁵⁹Cr

mass number	59
neutron number	35
Relative Atomic Mass	58,948345426 ± 0,00000072 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	1 050 ± 90 ms
spin	1/2
nuclear quadrupole moment	0
time of discovery or invention	1980
parity	-

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

⁶⁰Cr

mass number	60
neutron number	36
Relative Atomic Mass	59,949641656 ± 0,0000012 Da
g-factor	0
natural abundance
radioactivity	☢️ radioactive element
half-life	490 ± 10 ms
spin	0
nuclear quadrupole moment	0
time of discovery or invention	1980
parity	+

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

⁶¹Cr

mass number	61
neutron number	37
Relative Atomic Mass	60,95437813 ± 0,000002 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	243 ± 9 ms
spin	5/2
nuclear quadrupole moment
time of discovery or invention	1985
parity	-

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

⁶²Cr

mass number	62
neutron number	38
Relative Atomic Mass	61,95614292 ± 0,0000037 Da
g-factor	0
natural abundance
radioactivity	☢️ radioactive element
half-life	206 ± 12 ms
spin	0
nuclear quadrupole moment	0
time of discovery or invention	1985
parity	+

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

⁶³Cr

mass number	63
neutron number	39
Relative Atomic Mass	62,961161 ± 0,000078 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	129 ± 2 ms
spin	1/2
nuclear quadrupole moment	0
time of discovery or invention	1992
parity	-

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

⁶⁴Cr

mass number	64
neutron number	40
Relative Atomic Mass	63,963886 ± 0,000322 Da
g-factor	0
natural abundance
radioactivity	☢️ radioactive element
half-life	43 ± 1 ms
spin	0
nuclear quadrupole moment	0
time of discovery or invention	1992
parity	+

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

⁶⁵Cr

mass number	65
neutron number	41
Relative Atomic Mass	64,969608 ± 0,000215 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life	27,5 ± 2,1 ms
spin	1/2
nuclear quadrupole moment	0
time of discovery or invention	1997
parity	-

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

⁶⁶Cr

mass number	66
neutron number	42
Relative Atomic Mass	65,973011 ± 0,000322 Da
g-factor	0
natural abundance
radioactivity	☢️ radioactive element
half-life	23,8 ± 1,8 ms
spin	0
nuclear quadrupole moment	0
time of discovery or invention	1997
parity	+

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

⁶⁷Cr

mass number	67
neutron number	43
Relative Atomic Mass	66,979313 ± 0,000429 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life
spin	1/2
nuclear quadrupole moment	0
time of discovery or invention	1997
parity	-

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

⁶⁸Cr

mass number	68
neutron number	44
Relative Atomic Mass	67,983156 ± 0,000537 Da
g-factor	0
natural abundance
radioactivity	☢️ radioactive element
half-life
spin	0
nuclear quadrupole moment	0
time of discovery or invention	2009
parity	+

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

⁶⁹Cr

mass number	69
neutron number	45
Relative Atomic Mass	68,989662 ± 0,000537 Da
g-factor
natural abundance
radioactivity	☢️ radioactive element
half-life
spin	7/2
nuclear quadrupole moment
time of discovery or invention	2013
parity	+

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

⁷⁰Cr

mass number	70
neutron number	46
Relative Atomic Mass	69,993945 ± 0,000644 Da
g-factor	0
natural abundance
radioactivity	☢️ radioactive element
half-life
spin	0
nuclear quadrupole moment	0
time of discovery or invention	2013
parity	+

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

history

discoverer or inventor	Louis Vauquelin
location of discovery	France
time of discovery or invention	1797
etymology	Greek: chrôma (color).
pronunciation	KROH-mi-em (engelsk)

source

Abundance
Abundance in Earth's crust	102 mg/kg
natural abundance (ocean)	0,0003 mg/L
natural abundance (human body)	0,000003 %
natural abundance (meteoroid)	0,3 %
natural abundance (Sun)	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

Krom on ChemicalAid

Krom (Cr)

Physical Property

Chemical Property

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

history

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