Manganese Chromium Comparison
Periodic Table
Symbol
Mn
Cr
Group Number
7
11
6
12
Period Number
4
4
Block
d block
d block
Element Family
Transition Metal
Transition Metal
CAS Number
7439965
99+
7440473
39
Space Group Name
I_ 43m
Im_ 3m
Space Group Number
217.00
4
229.00
1
Facts
Interesting Facts
- Manganese is an essential trace element in all forms of life.
- Manganese metal oxidizes very easily, but it does not fuse that easily.
- 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
Found in Minerals, Mining, Ores of Minerals
Found in Minerals, Mining, Ores of metals, Ores of Minerals
History
Who Discovered
Johann Gottlieb Gahn
Louis Nicolas Vauquelin
Discovery
In 1774
In Between 1797 - 1798
Abundance
Abundance In Universe
8 * 10-4 %
8
1.5 * 10-3 %
7
Abundance In Sun
~0.001 %
8
~0.002 %
7
Abundance In Meteorites
0.27 %
8
0.30 %
7
Abundance In Earth's Crust
0.11 %
8
0.01 %
13
Abundance In Oceans
0.00 %
13
0.00 %
16
Abundance In Humans
0.00 %
13
0.00 %
16
Uses
Uses & Benefits
- This metal is very brittle hence it mostly not used as a pure metal, but its alloys are very useful
- Its alloy Manganese steel is extremely strong and used in railway tracks, safes, prison bars and riffle barrels.
- 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
Automobile Industry, Electrical Industry, Electronic Industry
Automobile Industry, Chemical Industry
Medical Uses
NA
NA
Other Uses
Alloys
Alloys
Biological Properties
Toxicity
Toxic
Highly Toxic
Present in Human Body
Yes
Yes
In Blood
0.08 Blood/mg dm-3
14
0.11 Blood/mg dm-3
12
In Bone
100.00 p.p.m.
8
0.33 p.p.m.
21
Physical Properties
Melting Point
1,245.00 °C
37
1,857.00 °C
14
Boiling Point
1,962.00 °C
99+
2,672.00 °C
39
Appearance
Physical State
Solid
Solid
Color
Silver
Silver
Luster
Metallic
Metallic
Hardness
Mohs Hardness
6.00
6
8.50
1
Brinell Hardness
196.00 MPa
99+
687.00 MPa
16
Vickers Hardness
Not Available
1,060.00 MPa
10
Speed of Sound
5,150.00 m/s
7
5,940.00 m/s
5
Optical Properties
Allotropes
No
No
α Allotropes
Not Available
Not Available
β Allotropes
Not Available
Not Available
γ Allotropes
Not Available
Not Available
Chemical Properties
Chemical Formula
Mn
Cr
Isotopes
Known Isotopes
21
18
21
18
Electronegativity
Pauling Electronegativity
1.55
25
1.66
18
Sanderson Electronegativity
2.20
7
1.66
14
Allred Rochow Electronegativity
1.60
9
1.56
10
Allen Electronegativity
1.75
15
1.65
19
Electropositivity
Pauling Electropositivity
2.45
29
2.34
36
Ionization Energies
1st Energy Level
717.30 kJ/mol
30
26,130.00 kJ/mol
1
2nd Energy Level
1,509.00 kJ/mol
39
28,750.00 kJ/mol
1
3rd Energy Level
3,248.00 kJ/mol
21
34,230.00 kJ/mol
1
4th Energy Level
4,940.00 kJ/mol
20
37,066.00 kJ/mol
1
5th Energy Level
6,990.00 kJ/mol
17
97,510.00 kJ/mol
1
6th Energy Level
9,220.00 kJ/mol
16
105,800.00 kJ/mol
1
7th Energy level
11,500.00 kJ/mol
16
114,300.00 kJ/mol
1
8th Energy Level
18,770.00 kJ/mol
5
125,300.00 kJ/mol
1
9th Energy Level
21,400.00 kJ/mol
6
134,700.00 kJ/mol
1
10th Energy Level
23,960.00 kJ/mol
9
144,300.00 kJ/mol
1
11th Energy Level
27,590.00 kJ/mol
10
26,130.00 kJ/mol
12
12th Energy Level
30,330.00 kJ/mol
10
28,750.00 kJ/mol
13
13th Energy Level
33,150.00 kJ/mol
11
34,230.00 kJ/mol
10
14th Energy Level
38,880.00 kJ/mol
10
37,066.00 kJ/mol
12
15th Energy Level
41,987.00 kJ/mol
13
97,510.00 kJ/mol
1
16th Energy Level
109,480.00 kJ/mol
1
105,800.00 kJ/mol
2
17th Energy Level
118,100.00 kJ/mol
2
114,300.00 kJ/mol
3
18th Energy Level
127,100.00 kJ/mol
3
125,300.00 kJ/mol
4
19th Energy Level
138,600.00 kJ/mol
4
134,700.00 kJ/mol
5
20th Energy Level
148,500.00 kJ/mol
6
144,300.00 kJ/mol
7
21st Energy Level
158,600.00 kJ/mol
6
157,700.00 kJ/mol
7
22nd Energy Level
172,500.00 kJ/mol
5
166,090.00 kJ/mol
6
23rd Energy Level
181,380.00 kJ/mol
5
Not Available
Electrochemical Equivalent
0.29 g/amp-hr
99+
0.32 g/amp-hr
99+
Electron Work Function
4.10 eV
25
4.50 eV
14
Other Chemical Properties
Ionization, Radioactive Isotopes
Anti Corrosion, Chemical Stability, Ionization, Radioactive Isotopes, Solubility
Atomic Properties
Atomic Number
25
99+
24
99+
Electron Configuration
[Ar] 3d5 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
Number of Protons
25
99+
24
99+
Number of Neutrons
30
99+
28
99+
Number of Electrons
25
99+
24
99+
Radius of an Atom
Atomic Radius
127.00 pm
99+
128.00 pm
99+
Covalent Radius
139.00 pm
99+
139.00 pm
99+
Van der Waals Radius
200.00 pm
28
200.00 pm
28
Atomic Weight
54.94 amu
99+
52.00 amu
99+
Atomic Volume
1.39 cm3/mol
99+
7.23 cm3/mol
99+
Adjacent Atomic Numbers
Valence Electron Potential
220.00 (-eV)
2
170.00 (-eV)
4
Lattice Constant
891.25 pm
1
291.00 pm
99+
Lattice Angles
π/2, π/2, π/2
π/2, π/2, π/2
Lattice C/A Ratio
Not Available
Not Available
Mechanical Properties
Density
Density At Room Temperature
7.21 g/cm3
99+
7.19 g/cm3
99+
Density When Liquid (at m.p.)
5.95 g/cm3
99+
6.30 g/cm3
40
Tensile Strength
Not Available
689.00 MPa
7
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 1000 K
0.00 (Pa)
12
0.00 (Pa)
24
Vapor Pressure at 2000 K
Not Available
774.00 (Pa)
1
Elasticity properties
Shear Modulus
Not Available
115.00 GPa
9
Bulk Modulus
120.00 GPa
14
160.00 GPa
11
Young's Modulus
198.00 GPa
12
279.00 GPa
8
Poisson Ratio
Not Available
0.21
32
Other Mechanical Properties
NA
NA
Magnetic Properties
Magnetic Characteristics
Specific Gravity
7.21
99+
7.19
99+
Magnetic Ordering
Paramagnetic
Antiferromagnetic
Electrical Properties
Electrical Property
Conductor
NA
Resistivity
1.44 nΩ·m
99+
125.00 nΩ·m
27
Electrical Conductivity
0.01 106/cm Ω
99+
0.08 106/cm Ω
25
Electron Affinity
0.00 kJ/mol
40
64.30 kJ/mol
15
Thermal Properties
Specific Heat
0.48 J/(kg K)
11
0.45 J/(kg K)
12
Molar Heat Capacity
26.32 J/mol·K
29
23.35 J/mol·K
99+
Thermal Conductivity
7.81 W/m·K
99+
93.90 W/m·K
17
Critical Temperature
Not Available
Not Available
Thermal Expansion
21.70 µm/(m·K)
21
4.90 µm/(m·K)
99+
Enthalpy
Enthalpy of Vaporization
219.70 kJ/mol
99+
348.80 kJ/mol
24
Enthalpy of Fusion
14.64 kJ/mol
23
15.31 kJ/mol
20
Enthalpy of Atomization
280.30 kJ/mol
38
397.50 kJ/mol
21
Standard Molar Entropy
32.00 J/mol.K
99+
23.80 J/mol.K
99+
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