କ୍ରୋମିୟମ

Chromium,  ₂₄Cr

ସାଧାରଣ ଗୁଣ
ନାମ, ପ୍ରତୀକ	chromium, Cr
Appearance	silvery metallic
ଉଚ୍ଚାରଣ	/ˈkroʊmiəm/ KROH-mee-əm
Chromium in the periodic table
- ↑ Cr ↓ Mo vanadium ← chromium → manganese
ପରମାଣୁ କ୍ରମାଙ୍କ (Z)	24
ଶ୍ରେଣୀ, ବ୍ଳକ	group 6, d-block
ପର୍ଯ୍ୟାୟ	period 4
ମୌଳିକ ପ୍ରକାର	transition metal
ମାନକ ପରମାଣବିକ ଓଜନ (±) (Ar)	51.9961(6)
ଇଲେକ୍‌ଟ୍ରୋନ୍ ବିନ୍ୟାସ	[Ar] 3d5 4s1
per shell	2, 8, 13, 1
ଭୌତିକ ଗୁଣ
ଅବସ୍ଥା	solid
ଗଳନାଙ୍କ	2180 K ​(1907 °C, ​3465 °F)
ସ୍ଫୁଟନାଙ୍କ	2944 K ​(2671 °C, ​4840 °F)
Density near r.t.	7.19 g/cm3
when liquid, at m.p.	6.3 g/cm3
Heat of fusion	21.0 kJ/mol
Heat of	339.5 kJ/mol
Molar heat capacity	23.35 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	6, 5, 4, 3, 2, 1, -1, -2 ​strongly acidic oxide
Electronegativity	Pauling scale: 1.66
energies	(more)
Atomic radius	empirical: 128 pm
Covalent radius	139±5 pm
Miscellanea
Crystal structure	​body-centered cubic (bcc)
Speed of sound thin rod	5940 m/s (at 20 °C)
Thermal expansion	4.9 µm/(m·K) (at 25 °C)
Thermal conductivity	93.9 W/(m·K)
Electrical resistivity	125 n Ω·m (at 20 °C)
Magnetic ordering	AFM (rather: SDW)
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 Number	7440-47-3
ଇତିହାସ
ଆବିଷ୍କାର	Louis Nicolas Vauquelin (1797)
First isolation	Louis Nicolas Vauquelin (1798)
Most stable 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

କ୍ରୋମିୟମ ହେଉଛି ଏକ ରାସାୟନିକ ମୌଳିକ ଯାହାର ପ୍ରତୀକ Cr ଓ ପରମାଣୁ କ୍ରମାଙ୍କ ୨୪ ।

ବାହାର ଲିଙ୍କ

• ATSDR Case Studies in Environmental Medicine: Chromium Toxicity Archived 2019-11-16 at the Wayback Machine. U.S. Department of Health and Human Services
• IARC Monograph "Chromium and Chromium compounds"
• It's Elemental – The Element Chromium Archived 2008-06-11 at the Wayback Machine.
• National Pollutant Inventory – Chromium (III) compounds fact sheet
• The Merck Manual – Mineral Deficiency and Toxicity
• National Institute for Occupational Safety and Health – Chromium Page
• Chromium at The Periodic Table of Videos (University of Nottingham)