Krom

Krom (Cr)

grundämne
Atomnummer24
Atommassa51.9961
masstal52
Grupp6
Period4
Blockd
Protoner24 p+
Neutroner28 n0
Electrons24 e-
Animated Bohrs atommodell of Cr (Krom)

Egenskaper

fysisk egenskap
atomradie
140 pm
molvolym
7,23 cm³/mol
kovalent radie
122 pm
Metallic Radius
119 pm
ionic radius
73 pm
Crystal Radius
87 pm
Van der Waalsradie
206 pm
densitet
7,15 g/cm³
energi
proton affinity
791,3 kJ/mol
Elektronaffinitet
0,666 eV/particle
joniseringsenergi
6,76651 eV/particle
joniseringsenergi of Cr (Krom)
ångbildningsvärme
342 kJ/mol
smältvärme
21 kJ/mol
Bildningsentalpi
397,48 kJ/mol
Electrons
electron shell2, 8, 13, 1
Bohrs atommodell: Cr (Krom)
valenselektron1
elektronkonfiguration[Ar] 3d5 4s1
Enhanced Bohrs atommodell of Cr (Krom)
Orbital Diagram of Cr (Krom)
oxidationstal-4, -2, -1, 0, 1, 2, 3, 4, 5, 6
elektronegativitet
1.66
Electrophilicity
1,1319177597467263 eV/particle
Phases
aggregationstillståndFast
Gas Phase
Kokpunkt
2 944,15 K
Smältpunkt
2 180,15 K
critical pressure
critical temperature
trippelpunkt
Visual
färg
Silver
appearancesilvery metallic
Brytningsindex
materialegenskap
Värmeledningsförmåga
93,9 W/(m K)
termisk expansion
0,0000049 1/K
molar heat capacity
23,35 J/(mol K)
Specifik värmekapacitet
0,449 J/(g⋅K)
heat capacity ratio
electrical properties
typeConductor
elektrisk konduktivitet
7,9 MS/m
resistivitet
0,00000013 m Ω
supraledare
magnetism
typeantiferromagnetic
magnetisk susceptibilitet (Mass)
0,0000000445 m³/Kg
magnetisk susceptibilitet (Molar)
0,000000002314 m³/mol
magnetisk susceptibilitet (Volume)
0,0003177
magnetic ordering
Curiepunkten
Néel temperature
393 K
Structure
KristallstrukturRymdcentrerat kubisk (BCC)
Gitterkonstant
2,88 Å
Lattice Anglesπ/2, π/2, π/2
mekanisk materialegenskap
hårdhet
8,5 MPa
Kompressibilitet
160 GPa
skjuvmodul
115 GPa
Young's modulus
279 GPa
Poissons konstant
0,21
ljudhastighet
5 940 m/s
klassificering
KategoriÖvergångsmetaller, Transition metals
CAS GroupVIA
IUPAC GroupVIB
Glawe Number55
Mendeleev Number51
Pettifor Number57
Geochemical Classfirst series transition metal
Goldschmidt classificationlitophile
övrigt
Gas Basicity
768,4 kJ/mol
Dipole Polarizability
83 ± 12 a₀
C6 Dispersion Coefficient
602 a₀
Allotropes
Träffyta
3,1
Neutron Mass Absorption
0,0021
kvanttal7S3
rymdgrupp229 (Im_3m)

Kromisotoper

Stabila isotoper4
Instabila isotoper26
Radioactive Isotopes25

41Cr

natural abundance
relative atomic mass
41,021911 ± 0,000429 Da
masstal41
g-factor
Halveringstid
Spinn3/2
nuclear quadrupole moment
upptäcktsdatum
Paritet+
41Cr Decay Modes
decay modeIntensitet
p (proton emission)%

42Cr

natural abundanceRadioactive ☢️
relative atomic mass
42,007579 ± 0,000322 Da
masstal42
g-factor
0
Halveringstid
13,3 ± 1 ms
Spinn0
nuclear quadrupole moment
0
upptäcktsdatum1996
Paritet+
42Cr Decay Modes
decay modeIntensitet
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)94.4%
2p (2-proton emission)%

43Cr

natural abundanceRadioactive ☢️
relative atomic mass
42,997885 ± 0,000215 Da
masstal43
g-factor
Halveringstid
21,1 ± 0,3 ms
Spinn3/2
nuclear quadrupole moment
upptäcktsdatum1992
Paritet+
43Cr Decay Modes
decay modeIntensitet
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

natural abundanceRadioactive ☢️
relative atomic mass
43,985591 ± 0,000055 Da
masstal44
g-factor
0
Halveringstid
42,8 ± 0,6 ms
Spinn0
nuclear quadrupole moment
0
upptäcktsdatum1987
Paritet+
44Cr Decay Modes
decay modeIntensitet
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)12%

45Cr

natural abundanceRadioactive ☢️
relative atomic mass
44,97905 ± 0,000038 Da
masstal45
g-factor
Halveringstid
60,9 ± 0,4 ms
Spinn7/2
nuclear quadrupole moment
upptäcktsdatum1974
Paritet-
45Cr Decay Modes
decay modeIntensitet
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)34.4%

46Cr

natural abundanceRadioactive ☢️
relative atomic mass
45,968360969 ± 0,000012295 Da
masstal46
g-factor
0
Halveringstid
224,3 ± 1,3 ms
Spinn0
nuclear quadrupole moment
0
upptäcktsdatum1972
Paritet+
46Cr Decay Modes
decay modeIntensitet
β+ (β+ decay; β+ = ϵ + e+)100%

47Cr

natural abundanceRadioactive ☢️
relative atomic mass
46,962894995 ± 0,000005578 Da
masstal47
g-factor
Halveringstid
461,6 ± 1,5 ms
Spinn3/2
nuclear quadrupole moment
upptäcktsdatum1972
Paritet-
47Cr Decay Modes
decay modeIntensitet
β+ (β+ decay; β+ = ϵ + e+)100%

48Cr

natural abundanceRadioactive ☢️
relative atomic mass
47,954029431 ± 0,000007848 Da
masstal48
g-factor
0
Halveringstid
21,56 ± 0,03 h
Spinn0
nuclear quadrupole moment
0
upptäcktsdatum1952
Paritet+
48Cr Decay Modes
decay modeIntensitet
β+ (β+ decay; β+ = ϵ + e+)100%

49Cr

natural abundanceRadioactive ☢️
relative atomic mass
48,95133372 ± 0,000002363 Da
masstal49
g-factor
0,1904 ± 0,0012
Halveringstid
42,3 ± 0,1 m
Spinn5/2
nuclear quadrupole moment
upptäcktsdatum1942
Paritet-
49Cr Decay Modes
decay modeIntensitet
β+ (β+ decay; β+ = ϵ + e+)100%

50Cr

natural abundance
4,345 ± 0,013
relative atomic mass
49,946042209 ± 0,0000001 Da
masstal50
g-factor
0
Halveringstid
Spinn0
nuclear quadrupole moment
0
upptäcktsdatum1930
Paritet+
50Cr Decay Modes
decay modeIntensitet
2β+ (double β+ decay)%

51Cr

natural abundanceRadioactive ☢️
relative atomic mass
50,944765388 ± 0,000000178 Da
masstal51
g-factor
0,26685714285714 ± 0,0014285714285714
Halveringstid
27,7015 ± 0,0011 d
Spinn7/2
nuclear quadrupole moment
upptäcktsdatum1940
Paritet-
51Cr Decay Modes
decay modeIntensitet
ϵ (electron capture)100%

52Cr

natural abundance
83,789 ± 0,018
relative atomic mass
51,940504714 ± 0,00000012 Da
masstal52
g-factor
0
Halveringstid
Spinn0
nuclear quadrupole moment
0
upptäcktsdatum1923
Paritet+

53Cr

natural abundance
9,501 ± 0,017
relative atomic mass
52,940646304 ± 0,000000124 Da
masstal53
g-factor
Halveringstid
Spinn3/2
nuclear quadrupole moment
−0,15 ± 0,05
upptäcktsdatum1930
Paritet-

54Cr

natural abundance
2,365 ± 0,007
relative atomic mass
53,938877359 ± 0,000000142 Da
masstal54
g-factor
0
Halveringstid
Spinn0
nuclear quadrupole moment
0
upptäcktsdatum1930
Paritet+

55Cr

natural abundanceRadioactive ☢️
relative atomic mass
54,940836637 ± 0,000000245 Da
masstal55
g-factor
Halveringstid
3,497 ± 0,003 m
Spinn3/2
nuclear quadrupole moment
upptäcktsdatum1952
Paritet-
55Cr Decay Modes
decay modeIntensitet
β− (β− decay)100%

56Cr

natural abundanceRadioactive ☢️
relative atomic mass
55,940648977 ± 0,00000062 Da
masstal56
g-factor
0
Halveringstid
5,94 ± 0,1 m
Spinn0
nuclear quadrupole moment
0
upptäcktsdatum1960
Paritet+
56Cr Decay Modes
decay modeIntensitet
β− (β− decay)100%

57Cr

natural abundanceRadioactive ☢️
relative atomic mass
56,943612112 ± 0,000002 Da
masstal57
g-factor
Halveringstid
21,1 ± 1 s
Spinn3/2
nuclear quadrupole moment
upptäcktsdatum1978
Paritet
57Cr Decay Modes
decay modeIntensitet
β− (β− decay)100%

58Cr

natural abundanceRadioactive ☢️
relative atomic mass
57,944184501 ± 0,0000032 Da
masstal58
g-factor
0
Halveringstid
7 ± 0,3 s
Spinn0
nuclear quadrupole moment
0
upptäcktsdatum1980
Paritet+
58Cr Decay Modes
decay modeIntensitet
β− (β− decay)100%

59Cr

natural abundanceRadioactive ☢️
relative atomic mass
58,948345426 ± 0,00000072 Da
masstal59
g-factor
Halveringstid
1 050 ± 90 ms
Spinn1/2
nuclear quadrupole moment
0
upptäcktsdatum1980
Paritet-
59Cr Decay Modes
decay modeIntensitet
β− (β− decay)100%

60Cr

natural abundanceRadioactive ☢️
relative atomic mass
59,949641656 ± 0,0000012 Da
masstal60
g-factor
0
Halveringstid
490 ± 10 ms
Spinn0
nuclear quadrupole moment
0
upptäcktsdatum1980
Paritet+
60Cr Decay Modes
decay modeIntensitet
β− (β− decay)100%
β− n (β−-delayed neutron emission)%

61Cr

natural abundanceRadioactive ☢️
relative atomic mass
60,95437813 ± 0,000002 Da
masstal61
g-factor
Halveringstid
243 ± 9 ms
Spinn5/2
nuclear quadrupole moment
upptäcktsdatum1985
Paritet-
61Cr Decay Modes
decay modeIntensitet
β− (β− decay)100%
β− n (β−-delayed neutron emission)%

62Cr

natural abundanceRadioactive ☢️
relative atomic mass
61,95614292 ± 0,0000037 Da
masstal62
g-factor
0
Halveringstid
206 ± 12 ms
Spinn0
nuclear quadrupole moment
0
upptäcktsdatum1985
Paritet+
62Cr Decay Modes
decay modeIntensitet
β− (β− decay)100%
β− n (β−-delayed neutron emission)%

63Cr

natural abundanceRadioactive ☢️
relative atomic mass
62,961161 ± 0,000078 Da
masstal63
g-factor
Halveringstid
129 ± 2 ms
Spinn1/2
nuclear quadrupole moment
0
upptäcktsdatum1992
Paritet-
63Cr Decay Modes
decay modeIntensitet
β− (β− decay)100%
β− n (β−-delayed neutron emission)%

64Cr

natural abundanceRadioactive ☢️
relative atomic mass
63,963886 ± 0,000322 Da
masstal64
g-factor
0
Halveringstid
43 ± 1 ms
Spinn0
nuclear quadrupole moment
0
upptäcktsdatum1992
Paritet+
64Cr Decay Modes
decay modeIntensitet
β− (β− decay)100%
β− n (β−-delayed neutron emission)%

65Cr

natural abundanceRadioactive ☢️
relative atomic mass
64,969608 ± 0,000215 Da
masstal65
g-factor
Halveringstid
27,5 ± 2,1 ms
Spinn1/2
nuclear quadrupole moment
0
upptäcktsdatum1997
Paritet-
65Cr Decay Modes
decay modeIntensitet
β− (β− decay)100%
β− n (β−-delayed neutron emission)%
2n (2-neutron emission)%

66Cr

natural abundanceRadioactive ☢️
relative atomic mass
65,973011 ± 0,000322 Da
masstal66
g-factor
0
Halveringstid
23,8 ± 1,8 ms
Spinn0
nuclear quadrupole moment
0
upptäcktsdatum1997
Paritet+
66Cr Decay Modes
decay modeIntensitet
β− (β− decay)100%
β− n (β−-delayed neutron emission)%
2n (2-neutron emission)%

67Cr

natural abundanceRadioactive ☢️
relative atomic mass
66,979313 ± 0,000429 Da
masstal67
g-factor
Halveringstid
Spinn1/2
nuclear quadrupole moment
0
upptäcktsdatum1997
Paritet-
67Cr Decay Modes
decay modeIntensitet
β− (β− decay)%
β− n (β−-delayed neutron emission)%
2n (2-neutron emission)%

68Cr

natural abundanceRadioactive ☢️
relative atomic mass
67,983156 ± 0,000537 Da
masstal68
g-factor
0
Halveringstid
Spinn0
nuclear quadrupole moment
0
upptäcktsdatum2009
Paritet+
68Cr Decay Modes
decay modeIntensitet
β− (β− decay)%
β− n (β−-delayed neutron emission)%
2n (2-neutron emission)%

69Cr

natural abundanceRadioactive ☢️
relative atomic mass
68,989662 ± 0,000537 Da
masstal69
g-factor
Halveringstid
Spinn7/2
nuclear quadrupole moment
upptäcktsdatum2013
Paritet+
69Cr Decay Modes
decay modeIntensitet
β− (β− decay)%
β− n (β−-delayed neutron emission)%
2n (2-neutron emission)%

70Cr

natural abundanceRadioactive ☢️
relative atomic mass
69,993945 ± 0,000644 Da
masstal70
g-factor
0
Halveringstid
Spinn0
nuclear quadrupole moment
0
upptäcktsdatum2013
Paritet+
70Cr Decay Modes
decay modeIntensitet
β− (β− decay)%
β− n (β−-delayed neutron emission)%
2n (2-neutron emission)%
Chromium crystals and 1cm3 cube

historia

upptäckare eller uppfinnareLouis Vauquelin
fyndplatsFrance
upptäcktsdatum1797
etymologiGreek: chrôma (color).
uttalKROH-mi-em (engelska)

Sources

Förekomst
Abundance in Earth's crust
102 mg/kg
Abundance in Oceans
0,0003 mg/L
Abundance in Human Body
0,000003 %
Abundance in Meteor
0,3 %
Abundance in Sun
0,002 %
Abundance in Universe
0,0015 %

Nuclear Screening Constants

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