CHROMIUM, Cr (24)

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Chromium Ore
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CHROMIUM

Cr (24)

ˈkrəʊmiəm

PHONETICS

Chromium is a steely-grey, lustrous, hard, brittle metal which takes a high polish, resists tarnishing, and has a high melting point. Chromium oxide was used by the Chinese in the Qin dynasty over 2,000 years ago to coat weapons found with the Terracotta Army.

ELEMENT BRIEF

1797 by Louis-Nicholas Vauquelin, France.

DISCOVERY

Ancient Greek, χρῶμα (khrôma, 'colour') + -ium.

ETYMOLOGY

Chromium

ELEMENT

Cr

SYMBOL

24

ATOMIC NUMBER

7440-47-3

CAS NUMBER
element

ELEMENTAL SPECTRUM


Silver

ELEMENTAL COLOUR


-

REFRACTIVE INDEX


0.210

POISSON RATIO


7.282 cm³

MOLAR VOLUME


1.12G Pa, 11.053'5k Atm

BRINELL HARDNESS


8.50

MOHS HARDNESS


1.06G Pa, 10.461'4k Atm

VICKERS HARDNESS


5,940 m/s, Mach 17.317'8

SPEED OF SOUND


160.00G Pa, 1.579'1M Atm

BULK MODULUS


115.00G Pa, 1.135'0M Atm

SHEAR MODULUS


279.00G Pa, 2.753'5M Atm

YOUNG MODULUS


ALLOTROPES

element element

2,180.15 K, 1,907.00 °C

MELTING POINT


2,944.15 K, 2,671.00 °C

BOILING POINT


673.15 K, 400.00 °C

AUTOMATIC IGNITION


-

FLASHPOINT


-

CRITICAL TEMPERATURE


-

CRITICAL PRESSURE


94.000'000 W/(m K)

THERMAL CONDUCTIVITY


0.000'004'9 K¯¹

THERMAL EXPANSION


448.00 J/(kg K)

SPECIFIC HEAT


20.500 kJ/mol

HEAT FUSION


339.000 kJ/mol

HEAT VAPORISATION


-

HEAT COMBUSTION


-

CURIE POINT


393.00 K, 119.85 °C

NEEL POINT


-

ADIABATIC INDEX


Solid

PHASE

Conductor

ELECTRICAL TYPE


7.90M S/m

CONDUCTIVITY


130.00n Ω.m

RESISTIVITY


-

SUPERCONDUCTING POINT


Antiferromagnetic

MAGNETIC TYPE


0.000'000'044'5

MASS SUSCEPTIBILITY


0.000'000'002'314'00

MOLAR SUSCEPTIBILITY


0.000'317'700'00

VOLUME SUSCEPTIBILITY

Transition Metal

CLASSIFICATION


0.000'317'700'00

ATOMIC WEIGHT


166 pm

ATOMIC RADIUS


122 pm

COVALENT RADIUS SINGLE BOND


111 pm

COVALENT RADIUS DOUBLE BOND


103 pm

COVALENT RADIUS TRIPLE BOND


189 pm

VAN DER WAALS RADIUS


[Ar]4s¹3d⁵

ELECTRON CONFIGURATION


Cubic, Body-centred

CRYSTAL STRUCTURE


7.140'00 g/cm³

DENSITY AS SOLID


6.300'00 g/cm³

DENSITY AS LIQUID


-

DENSITY AS GAS


lm_3m

SPACE GROUP NAME


229

SPACE GROUP NUMBER


π/2, π/2 π/2

LATTICE ANGLES


291, 291 291 pm

LATTICE CONSTANTS

6

VALENCE


1.66

ELECTRONEGATIVITY


65.21 kJ/mol

ELECTRON AFFINITY


IONISATION ENERGY

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0.001'5 %

UNIVERSE


0.3 %

METEORITES


0.002 %

SUN


0.014 %

EARTH CRUST


0.000'000'06 %

OCEANS


0.000'003 %

HUMANS

Stable

HALF LIFE


Stable

LIFETIME


3d⁵ = 3, 2, +2, +1/2

QUANTUM NUMBERS


3.490'00 b σs

NEUTRON CROSS SECTION


3.050'00 b σa

NEUTRON MASS ABSORPTION


STABLE ISOTOPES

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UNSTABLE ISOTOPES

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ISOTOPIC CHAIN

CENTRALDATACORE

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