Kromyo

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Chromium
24Cr
-

Cr

Mo
vanadiumchromiummanganese
Appearance
silvery metallic
General properties
Name, simbolo, kaiphan chromium, Cr, 24
Pronunciation Plantilya:IPAc-en Plantilya:Respell
Element category puthaw nga transisyon
Group, period, block 64, d
Standard atomic weight 51.9961(6)
Electron configuration [Ar] 3d5 4s1
2, 8, 13, 1
Electron shells of chromium (2, 8, 13, 1)
History
Discovery Louis Nicolas Vauquelin (1797)
First isolation Louis Nicolas Vauquelin (1798)
Physical properties
Phase magahi
Density (near r.t.) 7.19 g·cm−3
Liquid density at m.p. 6.3 g·cm−3
Melting point 2180 K, 1907 °C, 3465 °F
Boiling point 2944 K, 2671 °C, 4840 °F
Heat of fusion 21.0 kJ·mol−1
Heat of vaporization 339.5 kJ·mol−1
Molar heat capacity 23.35 J·mol−1·K−1
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1656 1807 1991 2223 2530 2942
Atomic properties
Oxidation states 6, 5, 4, 3, 2, 1, -1, -2
(strongly acidic oxide)
Electronegativity 1.66 (Pauling scale)
Ionization energies
(more)
1st: 652.9 kJ·mol−1
2nd: 1590.6 kJ·mol−1
3rd: 2987 kJ·mol−1
Atomic radius 128 pm
Covalent radius 139±5 pm
Miscellanea
Crystal structure body-centered cubic
Chromium has a body-centered cubic crystal structure
Magnetic ordering AFM (rather: SDW[1])
Electrical resistivity (20 °C) 125 nΩ·m
Thermal conductivity 93.9 W·m−1·K−1
Thermal expansion (25 °C) 4.9 µm·m−1·K−1
Speed of sound (thin rod) (20 °C) 5940 m·s−1
Young's modulus 279 GPa
Shear modulus 115 GPa
Bulk modulus 160 GPa
Poisson ratio 0.21
Mohs hardness 8.5
Vickers hardness 1060 MPa
Brinell hardness 1120 MPa
CAS registry number 7440-47-3
Most stable isotopes
Main article: Isotopes of chromium
iso NA half-life DM DE (MeV) DP
50Cr 4.345% >1.3×1018 y β+β+ 1.167 50Ti
51Cr syn 27.7025 d ε - 51V
γ 0.320 -
52Cr 83.789% 52Cr is stable with 28 neutrons
53Cr 9.501% 53Cr is stable with 29 neutrons
54Cr 2.365% 54Cr is stable with 30 neutrons
t  h  u
· r

Ang kromyo o cromo (Iningles chromium) mao ang elementong kimiko sa talaang peryodiko nga may simbolo nga Cr ug kaiphan nga atomik 24. Ang kromyo mao ang puthaw nga transisyon.

Ang mga gi basihan niini[usba | edit source]

  1. Fawcett, Eric (1988). "Spin-density-wave antiferromagnetism in chromium". Reviews of Modern Physics 60: 209. doi:10.1103/RevModPhys.60.209. Bibcode1988RvMP...60..209F. 


Galeriya sa hulagway[usba | edit source]