Symbol
Cr
  
Ni
  
Period Number
4
  
4
  
Block
d block
  
d block
  
Element Family
Transition Metal
  
Transition Metal
  
Space Group Name
Im_ 3m
  
Fm_ 3m
  
Interesting Facts
- Chromium is highly reactive, hence it is not found free in nature.
- Ores of Chromites mineral are the major source of Chromium metal.
- Almost 90% leather tanning is done with the help of chromium.
  
- Zinc metal found (obtain) in many forms like granules, foil, dust and in a powder form.
- After iron, Zinc metal the second most abundant element in the earth crust.
  
Sources
Found in Minerals, Mining, Ores of metals, Ores of Minerals
  
Found in Minerals, Mining, Ores of Minerals
  
History
  
  
Who Discovered
Louis Nicolas Vauquelin
  
Axel Fredrik Cronstedt
  
Discovery
In Between 1797 - 1798
  
In 1751
  
Abundance
  
  
Abundance In Universe
1.5 * 10-3 %
  
7
Abundance In Earth's Crust
Uses & Benefits
- It is used to harden the steel and produces a stainless steel and other various alloys.
- It is also used to give proper finish to polished mirrors. Its chromium plates are used in bathroom fittings.
  
- It has corrosion resistance and hence it is used to plate other metals.
- Its alloys are very useful; Nichrome alloy is used in the hot coil of toasters and electric oven.
  
Industrial Uses
Automobile Industry, Chemical Industry
  
Automobile Industry, Electrical Industry, Electronic Industry
  
Medical Uses
NA
  
NA
  
Other Uses
Alloys
  
Alloys
  
Biological Properties
  
  
Toxicity
Highly Toxic
  
Toxic
  
Present in Human Body
Yes
  
Yes
  
In Blood
0.11 Blood/mg dm-3
  
12
0.05 Blood/mg dm-3
  
17
In Bone
0.33 p.p.m.
  
21
0.70 p.p.m.
  
18
Melting Point
1,857.00 °C
  
14
1,453.00 °C
  
31
Boiling Point
2,672.00 °C
  
39
2,732.00 °C
  
38
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silver
  
Silver
  
Luster
Metallic
  
Metallic
  
Hardness
  
  
Vickers Hardness
1,060.00 MPa
  
10
Speed of Sound
5,940.00 m/s
  
5
4,900.00 m/s
  
12
Optical Properties
  
  
Reflectivity
Not Available
  
Allotropes
No
  
No
  
α Allotropes
Not Available
  
Not Available
  
β Allotropes
Not Available
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Cr
  
Ni
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Allred Rochow Electronegativity
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
26,130.00 kJ/mol
  
1
737.10 kJ/mol
  
25
2nd Energy Level
28,750.00 kJ/mol
  
1
1,753.00 kJ/mol
  
25
3rd Energy Level
34,230.00 kJ/mol
  
1
3,395.00 kJ/mol
  
17
4th Energy Level
37,066.00 kJ/mol
  
1
5,300.00 kJ/mol
  
15
5th Energy Level
97,510.00 kJ/mol
  
1
7,339.00 kJ/mol
  
15
6th Energy Level
105,800.00 kJ/mol
  
1
10,400.00 kJ/mol
  
9
7th Energy level
114,300.00 kJ/mol
  
1
12,800.00 kJ/mol
  
10
8th Energy Level
125,300.00 kJ/mol
  
1
15,600.00 kJ/mol
  
10
9th Energy Level
134,700.00 kJ/mol
  
1
18,600.00 kJ/mol
  
10
10th Energy Level
144,300.00 kJ/mol
  
1
21,670.00 kJ/mol
  
14
11th Energy Level
26,130.00 kJ/mol
  
12
30,970.00 kJ/mol
  
7
12th Energy Level
28,750.00 kJ/mol
  
13
34,000.00 kJ/mol
  
7
13th Energy Level
34,230.00 kJ/mol
  
10
37,100.00 kJ/mol
  
7
14th Energy Level
37,066.00 kJ/mol
  
12
41,500.00 kJ/mol
  
8
15th Energy Level
97,510.00 kJ/mol
  
1
44,800.00 kJ/mol
  
10
16th Energy Level
105,800.00 kJ/mol
  
2
48,100.00 kJ/mol
  
12
17th Energy Level
114,300.00 kJ/mol
  
3
55,101.00 kJ/mol
  
11
18th Energy Level
125,300.00 kJ/mol
  
4
58,570.00 kJ/mol
  
12
19th Energy Level
134,700.00 kJ/mol
  
5
148,700.00 kJ/mol
  
1
20th Energy Level
144,300.00 kJ/mol
  
7
159,000.00 kJ/mol
  
3
21st Energy Level
157,700.00 kJ/mol
  
7
169,400.00 kJ/mol
  
3
22nd Energy Level
166,090.00 kJ/mol
  
6
182,700.00 kJ/mol
  
2
23rd Energy Level
Not Available
  
194,000.00 kJ/mol
  
2
Electrochemical Equivalent
0.32 g/amp-hr
  
99+
1.10 g/amp-hr
  
99+
Other Chemical Properties
Anti Corrosion, Chemical Stability, Ionization, Radioactive Isotopes, Solubility
  
Anti Corrosion, Ionization, Radioactive Isotopes
  
Electron Configuration
[Ar] 3d5 4s1
  
[Ar] 3d8 4s2 Or [Ar] 3d9 4s1
  
Crystal Structure
Body Centered Cubic (BCC)
  
Face Centered Cubic (FCC)
  
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
  
FCC-Crystal-Structure-of-Nickel.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Volume
7.23 cm3/mol
  
99+
6.59 cm3/mol
  
99+
Adjacent Atomic Numbers
  
  
Valence Electron Potential
170.00 (-eV)
  
4
42.00 (-eV)
  
99+
Lattice Angles
π/2, π/2, π/2
  
π/2, π/2, π/2
  
Lattice C/A Ratio
Not Available
  
Not Available
  
Density
  
  
Density At Room Temperature
7.19 g/cm3
  
99+
8.91 g/cm3
  
99+
Density When Liquid (at m.p.)
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Elasticity properties
  
  
Other Mechanical Properties
NA
  
Ductile
  
Magnetic Characteristics
  
  
Magnetic Ordering
Antiferromagnetic
  
Ferromagnetic
  
Permeability
Not Available
  
Susceptibility
Not Available
  
Electrical Properties
  
  
Electrical Property
NA
  
Conductor
  
Resistivity
125.00 nΩ·m
  
27
Electrical Conductivity
0.08 106/cm Ω
  
25
0.14 106/cm Ω
  
13
Electron Affinity
64.30 kJ/mol
  
15
112.00 kJ/mol
  
6
Specific Heat
0.45 J/(kg K)
  
12
0.44 J/(kg K)
  
13
Molar Heat Capacity
23.35 J/mol·K
  
99+
26.07 J/mol·K
  
31
Thermal Conductivity
93.90 W/m·K
  
17
90.90 W/m·K
  
18
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
4.90 µm/(m·K)
  
99+
13.40 µm/(m·K)
  
28
Enthalpy
  
  
Enthalpy of Vaporization
348.80 kJ/mol
  
24
371.80 kJ/mol
  
20
Enthalpy of Fusion
15.31 kJ/mol
  
20
17.57 kJ/mol
  
14
Enthalpy of Atomization
397.50 kJ/mol
  
21
422.60 kJ/mol
  
17
Standard Molar Entropy
23.80 J/mol.K
  
99+
29.90 J/mol.K
  
99+