Crom

Crom (Cr)

chemical element with symbol Cr and atomic number 24
Atomic Number24
Atomic Weight51.9961
Rhif màs52
Group6
Period4
Blockd
Proton24 p+
Niwtron28 n0
Electron24 e-
Animated Bohr model of Cr (Crom)

Nodwedd Ffisegol

Atomic Radius
140 pm
molar volume
covalent radius
122 pm
Metallic Radius
119 pm
ionic radius
73 pm
Crystal Radius
87 pm
Van der Waals radius
206 pm
density
7.15 g/cm³
Atomic Radii Of The Elements: Crom0102030405060708090100110120130140150160170180190200210pmAtomic RadiusCovalent RadiusMetallic RadiusVan der Waals radius

Nodwedd Gemegol

egni
proton affinity
791.3 kJ/mol
electron affinity
ionization energy
6.76651 eV/particle
ionization energy of Cr (Crom)
enthalpy of vaporization
342 kJ/mol
enthalpy of fusion
standard enthalpy of formation
397.48 kJ/mol
Electron
plisgyn yr electron2, 8, 13, 1
Bohr model: Cr (Crom)
valence electron1
Lewis structure: Cr (Crom)
trefn yr electronnau[Ar] 3d5 4s1
1s2 2s2 2p6 3s2 3p6 3d5 4s1
Enhanced Bohr model of Cr (Crom)
Orbital Diagram of Cr (Crom)
Cyflwr ocsidiad-4, -2, -1, 0, 1, 2, 3, 4, 5, 6
Electronegatifedd
1.66
Electrophilicity Index
1.1319177597467263 eV/particle
cyflwr sylfaenol mater
cyflwr materSolid
gaseous state of matter
Boiling Point
2,944.15 K
Melting Point
2,180.15 K
critical pressure
critical temperature
triple point
appearance
lliw
Silver
appearancesilvery 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
typeConductor
dargludedd trydanol
7.9 MS/m
Gwrthedd
0.00000013 m Ω
superconductivity
magnetism
typeantiferromagnetic
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 StructureBody Centered Cubic (BCC)
lattice constant
2.88 Å
Lattice Anglesπ/2, π/2, π/2
nodwedd mecanyddol deunyddiau
hardness
8.5 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
CategoryTransition metals, Transition metals
CAS GroupVIA
IUPAC GroupVIB
Glawe Number55
Mendeleev Number51
Pettifor Number57
Geochemical Classfirst series transition metal
Goldschmidt classificationlitophile

other

Gas Basicity
768.4 kJ/mol
polarizability
83 ± 12 a₀
C6 Dispersion Coefficient
602 a₀
allotrope
Neutron cross section
3.1
Neutron Mass Absorption
0.0021
quantum number7S3
space group229 (Im_3m)

Isotopes of Chromium

Stable Isotopes3
Unstable Isotopes27
Natural Isotopes4
Isotopic Composition5283.79%5283.79%539.50%539.50%504.35%504.35%542.37%542.37%

41Cr

Rhif màs41
neutron number17
relative atomic mass
41.021911 ± 0.000429 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
spin3/2
nuclear quadrupole moment
dyddiad darganfod
parity+

decay modeintensity
p (proton emission)

42Cr

Rhif màs42
neutron number18
relative atomic mass
42.007579 ± 0.000322 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
13.3 ± 1 ms
spin0
nuclear quadrupole moment
0
dyddiad darganfod1996
parity+

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

43Cr

Rhif màs43
neutron number19
relative atomic mass
42.997885 ± 0.000215 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
21.1 ± 0.3 ms
spin3/2
nuclear quadrupole moment
dyddiad darganfod1992
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)79.3%
2p (2-proton emission)11.6%
3p0.13%
β+α (β+-delayed α emission)

44Cr

Rhif màs44
neutron number20
relative atomic mass
43.985591 ± 0.000055 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
42.8 ± 0.6 ms
spin0
nuclear quadrupole moment
0
dyddiad darganfod1987
parity+

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

45Cr

Rhif màs45
neutron number21
relative atomic mass
44.97905 ± 0.000038 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
60.9 ± 0.4 ms
spin7/2
nuclear quadrupole moment
dyddiad darganfod1974
parity-

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

46Cr

Rhif màs46
neutron number22
relative atomic mass
45.968360969 ± 0.000012295 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
224.3 ± 1.3 ms
spin0
nuclear quadrupole moment
0
dyddiad darganfod1972
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%

47Cr

Rhif màs47
neutron number23
relative atomic mass
46.962894995 ± 0.000005578 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
461.6 ± 1.5 ms
spin3/2
nuclear quadrupole moment
dyddiad darganfod1972
parity-

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%

48Cr

Rhif màs48
neutron number24
relative atomic mass
47.954029431 ± 0.000007848 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
21.56 ± 0.03 h
spin0
nuclear quadrupole moment
0
dyddiad darganfod1952
parity+

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%

49Cr

Rhif màs49
neutron number25
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
spin5/2
nuclear quadrupole moment
dyddiad darganfod1942
parity-

decay modeintensity
β+ (β+ decay; β+ = ϵ + e+)100%

50Cr

Rhif màs50
neutron number26
relative atomic mass
49.946042209 ± 0.0000001 Da
g-factor
0
natural abundance
4.345 ± 0.013
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
spin0
nuclear quadrupole moment
0
dyddiad darganfod1930
parity+

decay modeintensity
+ (double β+ decay)

51Cr

Rhif màs51
neutron number27
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
spin7/2
nuclear quadrupole moment
dyddiad darganfod1940
parity-

decay modeintensity
ϵ (electron capture)100%

52Cr

Rhif màs52
neutron number28
relative atomic mass
51.940504714 ± 0.00000012 Da
g-factor
0
natural abundance
83.789 ± 0.018
Dadfeilio ymbelydrolstable isotope
Hanner oesNot Radioactive ☢️
spin0
nuclear quadrupole moment
0
dyddiad darganfod1923
parity+

53Cr

Rhif màs53
neutron number29
relative atomic mass
52.940646304 ± 0.000000124 Da
g-factor
natural abundance
9.501 ± 0.017
Dadfeilio ymbelydrolstable isotope
Hanner oesNot Radioactive ☢️
spin3/2
nuclear quadrupole moment
-0.15 ± 0.05
dyddiad darganfod1930
parity-

54Cr

Rhif màs54
neutron number30
relative atomic mass
53.938877359 ± 0.000000142 Da
g-factor
0
natural abundance
2.365 ± 0.007
Dadfeilio ymbelydrolstable isotope
Hanner oesNot Radioactive ☢️
spin0
nuclear quadrupole moment
0
dyddiad darganfod1930
parity+

55Cr

Rhif màs55
neutron number31
relative atomic mass
54.940836637 ± 0.000000245 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
3.497 ± 0.003 m
spin3/2
nuclear quadrupole moment
dyddiad darganfod1952
parity-

decay modeintensity
β (β decay)100%

56Cr

Rhif màs56
neutron number32
relative atomic mass
55.940648977 ± 0.00000062 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
5.94 ± 0.1 m
spin0
nuclear quadrupole moment
0
dyddiad darganfod1960
parity+

decay modeintensity
β (β decay)100%

57Cr

Rhif màs57
neutron number33
relative atomic mass
56.943612112 ± 0.000002 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
21.1 ± 1 s
spin3/2
nuclear quadrupole moment
dyddiad darganfod1978
parity

decay modeintensity
β (β decay)100%

58Cr

Rhif màs58
neutron number34
relative atomic mass
57.944184501 ± 0.0000032 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
7 ± 0.3 s
spin0
nuclear quadrupole moment
0
dyddiad darganfod1980
parity+

decay modeintensity
β (β decay)100%

59Cr

Rhif màs59
neutron number35
relative atomic mass
58.948345426 ± 0.00000072 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
1,050 ± 90 ms
spin1/2
nuclear quadrupole moment
0
dyddiad darganfod1980
parity-

decay modeintensity
β (β decay)100%

60Cr

Rhif màs60
neutron number36
relative atomic mass
59.949641656 ± 0.0000012 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
490 ± 10 ms
spin0
nuclear quadrupole moment
0
dyddiad darganfod1980
parity+

decay modeintensity
β (β decay)100%
β n (β-delayed neutron emission)

61Cr

Rhif màs61
neutron number37
relative atomic mass
60.95437813 ± 0.000002 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
243 ± 9 ms
spin5/2
nuclear quadrupole moment
dyddiad darganfod1985
parity-

decay modeintensity
β (β decay)100%
β n (β-delayed neutron emission)

62Cr

Rhif màs62
neutron number38
relative atomic mass
61.95614292 ± 0.0000037 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
206 ± 12 ms
spin0
nuclear quadrupole moment
0
dyddiad darganfod1985
parity+

decay modeintensity
β (β decay)100%
β n (β-delayed neutron emission)

63Cr

Rhif màs63
neutron number39
relative atomic mass
62.961161 ± 0.000078 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
129 ± 2 ms
spin1/2
nuclear quadrupole moment
0
dyddiad darganfod1992
parity-

decay modeintensity
β (β decay)100%
β n (β-delayed neutron emission)

64Cr

Rhif màs64
neutron number40
relative atomic mass
63.963886 ± 0.000322 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
43 ± 1 ms
spin0
nuclear quadrupole moment
0
dyddiad darganfod1992
parity+

decay modeintensity
β (β decay)100%
β n (β-delayed neutron emission)

65Cr

Rhif màs65
neutron number41
relative atomic mass
64.969608 ± 0.000215 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
27.5 ± 2.1 ms
spin1/2
nuclear quadrupole moment
0
dyddiad darganfod1997
parity-

decay modeintensity
β (β decay)100%
β n (β-delayed neutron emission)
2n (2-neutron emission)

66Cr

Rhif màs66
neutron number42
relative atomic mass
65.973011 ± 0.000322 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
23.8 ± 1.8 ms
spin0
nuclear quadrupole moment
0
dyddiad darganfod1997
parity+

decay modeintensity
β (β decay)100%
β n (β-delayed neutron emission)
2n (2-neutron emission)

67Cr

Rhif màs67
neutron number43
relative atomic mass
66.979313 ± 0.000429 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
spin1/2
nuclear quadrupole moment
0
dyddiad darganfod1997
parity-

decay modeintensity
β (β decay)
β n (β-delayed neutron emission)
2n (2-neutron emission)

68Cr

Rhif màs68
neutron number44
relative atomic mass
67.983156 ± 0.000537 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
spin0
nuclear quadrupole moment
0
dyddiad darganfod2009
parity+

decay modeintensity
β (β decay)
β n (β-delayed neutron emission)
2n (2-neutron emission)

69Cr

Rhif màs69
neutron number45
relative atomic mass
68.989662 ± 0.000537 Da
g-factor
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
spin7/2
nuclear quadrupole moment
dyddiad darganfod2013
parity+

decay modeintensity
β (β decay)
β n (β-delayed neutron emission)
2n (2-neutron emission)

70Cr

Rhif màs70
neutron number46
relative atomic mass
69.993945 ± 0.000644 Da
g-factor
0
natural abundance
Dadfeilio ymbelydrol☢️ elfen ymbelydrol
Hanner oes
spin0
nuclear quadrupole moment
0
dyddiad darganfod2013
parity+

decay modeintensity
β (β decay)
β n (β-delayed neutron emission)
2n (2-neutron emission)
Chromium crystals and 1cm3 cube

hanes

darganfyddwr neu ddyfeisiwrLouis Vauquelin
man darganfodFrance
dyddiad darganfod1797
geirdarddiadGreek: chrôma (color).
ynganiadKROH-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

1s0.5862
2p3.9248
2s7.0162
3d14.2434
3p12.534
3s11.6322
4s18.8668