Symbol
Fe
  
Cr
  
Period Number
4
  
4
  
Block
d block
  
d block
  
Element Family
Transition Metal
  
Transition Metal
  
Space Group Name
Im_ 3m
  
Im_ 3m
  
Interesting Facts
- Iron is not always magnetic in nature, its allotrope are ferromagnetic and the B allotrope is nonmagnetic.
- The blood consists Iron in hemoglobin molecules to transfer Oxygen in the body.
  
- 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.
  
Sources
Earth's crust, Found in Minerals
  
Found in Minerals, Mining, Ores of metals, Ores of Minerals
  
History
  
  
Who Discovered
Unknown
  
Louis Nicolas Vauquelin
  
Discovery
Before 5000 BC
  
In Between 1797 - 1798
  
Abundance
  
  
Abundance In Universe
1.1 * 10-1 %
  
1
1.5 * 10-3 %
  
7
Abundance In Earth's Crust
Uses & Benefits
- Iron metal alloy steel is used in the application of civil engineering and manufacturing.
- Alloys of iron with nickel, vanadium, chromium, tungsten and manganese have very useful properties.
  
- 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.
  
Industrial Uses
Aerospace Industry, Automobile Industry, Chemical Industry, Electrical Industry, Electronic Industry
  
Automobile Industry, Chemical Industry
  
Medical Uses
Pharmaceutical Industry, Surgical Instruments Manufacturing
  
NA
  
Other Uses
Alloys, Sculptures, Statues
  
Alloys
  
Biological Properties
  
  
Toxicity
Non Toxic
  
Highly Toxic
  
Present in Human Body
Yes
  
Yes
  
In Blood
447.00 Blood/mg dm-3
  
3
0.11 Blood/mg dm-3
  
12
In Bone
380.00 p.p.m.
  
5
0.33 p.p.m.
  
21
Melting Point
1,535.00 °C
  
25
1,857.00 °C
  
14
Boiling Point
2,750.00 °C
  
37
2,672.00 °C
  
39
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Gray
  
Silver
  
Luster
Metallic
  
Metallic
  
Hardness
  
  
Vickers Hardness
1,060.00 MPa
  
10
Speed of Sound
5,120.00 m/s
  
8
5,940.00 m/s
  
5
Optical Properties
  
  
Reflectivity
Not Available
  
Allotropes
Yes
  
No
  
α Allotropes
Ferrite (alpha Iron)
  
Not Available
  
β Allotropes
beta Iron
  
Not Available
  
γ Allotropes
gamma Iron
  
Not Available
  
Chemical Formula
Fe
  
Cr
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Allred Rochow Electronegativity
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
762.50 kJ/mol
  
17
26,130.00 kJ/mol
  
1
2nd Energy Level
1,561.90 kJ/mol
  
36
28,750.00 kJ/mol
  
1
3rd Energy Level
2,957.00 kJ/mol
  
29
34,230.00 kJ/mol
  
1
4th Energy Level
5,290.00 kJ/mol
  
16
37,066.00 kJ/mol
  
1
5th Energy Level
7,240.00 kJ/mol
  
16
97,510.00 kJ/mol
  
1
6th Energy Level
9,560.00 kJ/mol
  
14
105,800.00 kJ/mol
  
1
7th Energy level
12,060.00 kJ/mol
  
15
114,300.00 kJ/mol
  
1
8th Energy Level
14,580.00 kJ/mol
  
14
125,300.00 kJ/mol
  
1
9th Energy Level
22,540.00 kJ/mol
  
5
134,700.00 kJ/mol
  
1
10th Energy Level
25,290.00 kJ/mol
  
8
144,300.00 kJ/mol
  
1
11th Energy Level
28,000.00 kJ/mol
  
9
26,130.00 kJ/mol
  
12
12th Energy Level
31,920.00 kJ/mol
  
9
28,750.00 kJ/mol
  
13
13th Energy Level
34,830.00 kJ/mol
  
9
34,230.00 kJ/mol
  
10
14th Energy Level
37,840.00 kJ/mol
  
11
37,066.00 kJ/mol
  
12
15th Energy Level
44,100.00 kJ/mol
  
11
97,510.00 kJ/mol
  
1
16th Energy Level
47,206.00 kJ/mol
  
13
105,800.00 kJ/mol
  
2
17th Energy Level
122,200.00 kJ/mol
  
1
114,300.00 kJ/mol
  
3
18th Energy Level
131,000.00 kJ/mol
  
2
125,300.00 kJ/mol
  
4
19th Energy Level
140,500.00 kJ/mol
  
3
134,700.00 kJ/mol
  
5
20th Energy Level
152,600.00 kJ/mol
  
5
144,300.00 kJ/mol
  
7
21st Energy Level
163,000.00 kJ/mol
  
5
157,700.00 kJ/mol
  
7
22nd Energy Level
173,600.00 kJ/mol
  
4
166,090.00 kJ/mol
  
6
23rd Energy Level
188,100.00 kJ/mol
  
4
Not Available
  
24th Energy Level
195,200.00 kJ/mol
  
1
Not Available
  
Electrochemical Equivalent
0.69 g/amp-hr
  
99+
0.32 g/amp-hr
  
99+
Other Chemical Properties
Corrosion, Ionization, Solubility
  
Anti Corrosion, Chemical Stability, Ionization, Radioactive Isotopes, Solubility
  
Electron Configuration
[Ar] 3d6 4s2
  
[Ar] 3d5 4s1
  
Crystal Structure
Body Centered Cubic (BCC)
  
Body Centered Cubic (BCC)
  
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
  
BCC-Crystal-Structure-.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Volume
7.10 cm3/mol
  
99+
7.23 cm3/mol
  
99+
Adjacent Atomic Numbers
  
  
Valence Electron Potential
67.00 (-eV)
  
20
170.00 (-eV)
  
4
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
7.87 g/cm3
  
99+
7.19 g/cm3
  
99+
Density When Liquid (at m.p.)
Tensile Strength
11,000.00 MPa
  
1
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Elasticity properties
  
  
Other Mechanical Properties
Ductile, Malleable, Weldable
  
NA
  
Magnetic Characteristics
  
  
Magnetic Ordering
Ferromagnetic
  
Antiferromagnetic
  
Permeability
6.3 * 10
-3 H/m
  
1
Not Available
  
Susceptibility
Not Available
  
Electrical Properties
  
  
Electrical Property
Conductor
  
NA
  
Resistivity
125.00 nΩ·m
  
27
Electrical Conductivity
0.10 106/cm Ω
  
20
0.08 106/cm Ω
  
25
Electron Affinity
15.70 kJ/mol
  
34
64.30 kJ/mol
  
15
Specific Heat
0.44 J/(kg K)
  
13
0.45 J/(kg K)
  
12
Molar Heat Capacity
25.10 J/mol·K
  
99+
23.35 J/mol·K
  
99+
Thermal Conductivity
80.40 W/m·K
  
22
93.90 W/m·K
  
17
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
11.80 µm/(m·K)
  
33
4.90 µm/(m·K)
  
99+
Enthalpy
  
  
Enthalpy of Vaporization
351.00 kJ/mol
  
23
348.80 kJ/mol
  
24
Enthalpy of Fusion
14.90 kJ/mol
  
22
15.31 kJ/mol
  
20
Enthalpy of Atomization
414.20 kJ/mol
  
19
397.50 kJ/mol
  
21
Standard Molar Entropy
27.30 J/mol.K
  
99+
23.80 J/mol.K
  
99+