Krómíọ̀mù

(Àtúnjúwe láti Chromium)
Chromium, 24Cr
Chromium
Ìhànsójúsilvery metallic
Ìwúwo átọ̀mù Ar, std(Cr)51.9961(6)[1]
Chromium ní orí tábìlì àyè
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson
-

Cr

Mo
vanadiumchromiummanganese
Nọ́mbà átọ̀mù (Z)24
Ẹgbẹ́group 6
Àyèàyè 4
Àdìpọ̀Àdìpọ̀-d
Ẹ̀ka ẹ́límẹ́ntì  Transition metal
Ìtò ẹ̀lẹ́ktrọ́nù[Ar] 3d5 4s1
Iye ẹ̀lẹ́ktrọ́nù lórí ìpele kọ̀ọ̀kan2, 8, 13, 1
Àwọn ohun ìní ara
Ìfarahàn at STPsolid
Ìgbà ìyọ́2180 K ​(1907 °C, ​3465 °F)
Ígbà ìhó2944 K ​(2671 °C, ​4840 °F)
Kíki (near r.t.)7.19 g/cm3
when liquid (at m.p.)6.3 g/cm3
Heat of fusion21.0 kJ/mol
Heat of 339.5 kJ/mol
Molar heat capacity23.35 J/(mol·K)
 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−4, −2, −1, 0, +1, +2, +3, +4, +5, +6 Àdàkọ:Infobox element/symbol-to-oxidation-state/comment
ElectronegativityPauling scale: 1.66
energies
Atomic radiusempirical: 128 pm
Covalent radius139±5 pm
Color lines in a spectral range
Color lines in a spectral range
Spectral lines of chromium
Other properties
Natural occurrenceprimordial
Crystal structure ​(bcc)
Body-centered cubic crystal structure for chromium
Speed of sound thin rod5940 m/s (at 20 °C)
Thermal expansion4.9 µm/(m·K) (at 25 °C)
Thermal conductivity93.9 W/(m·K)
Electrical resistivity125 n Ω·m (at 20 °C)
Magnetic orderingAFM (rather: SDW[2])
Young's modulus279 GPa
Shear modulus115 GPa
Bulk modulus160 GPa
Poisson ratio0.21
Mohs hardness8.5
Vickers hardness1060 MPa
Brinell hardness1120 MPa
CAS Number7440-47-3
Main isotopes of chromium
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct
50Cr 4.345% > 1.8×1017y εε - 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
Àdàkọ:Category-inline
| references


  1. Meija, Juris; Coplen, Tyler B.; Berglund, Michael; Brand, Willi A.; De Bièvre, Paul; Gröning, Manfred; Holden, Norman E.; Irrgeher, Johanna et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry 88 (3): 265–91. doi:10.1515/pac-2015-0305. 
  2. Fawcett, Eric (1988). "Spin-density-wave antiferromagnetism in chromium". Reviews of Modern Physics 60: 209. doi:10.1103/RevModPhys.60.209.