Rhenium Chromium Comparison
Periodic Table
Symbol
Re
Cr
Group Number
7
11
6
12
Period Number
6
4
Block
d block
d block
Element Family
Transition Metal
Transition Metal
CAS Number
7440155
99+
7440473
39
Space Group Name
P63/mmc
Im_ 3m
Space Group Number
194.00
5
229.00
1
Facts
Interesting Facts
- Chemical properties of Rhenium are similar to Manganese.
- Rhenium metal is created while refining Molybdenum.
- 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
Masataka Ogawa
Louis Nicolas Vauquelin
Discovery
In 1908
In Between 1797 - 1798
Abundance
Abundance In Universe
2 * 10-8 %
29
1.5 * 10-3 %
7
Abundance In Sun
~0.00000001 %
29
~0.002 %
7
Abundance In Meteorites
0.00 %
99+
0.30 %
7
Abundance In Earth's Crust
0.00 %
99+
0.01 %
13
Abundance In Oceans
0.00 %
34
0.00 %
16
Abundance In Humans
Not Available
0.00 %
16
Uses
Uses & Benefits
- Alloys of Rhenium are used as an electric contact material. It can resist withstand arc corrosion.
- Its catalysts are used in hydrogenation of fine chemicals. Its Alloy with nickel is used to produce turbine blades.
- 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
NA
NA
Other Uses
Alloys
Alloys
Biological Properties
Toxicity
Low Toxic
Highly Toxic
Present in Human Body
No
Yes
In Blood
Not Available
0.11 Blood/mg dm-3
12
In Bone
Not Available
0.33 p.p.m.
21
Physical Properties
Melting Point
3,180.00 °C
2
1,857.00 °C
14
Boiling Point
5,627.00 °C
2
2,672.00 °C
39
Appearance
Physical State
Solid
Solid
Color
Silvery Gray
Silver
Luster
Metallic
Metallic
Hardness
Mohs Hardness
7.00
3
8.50
1
Brinell Hardness
1,320.00 MPa
8
687.00 MPa
16
Vickers Hardness
1,350.00 MPa
7
1,060.00 MPa
10
Speed of Sound
4,700.00 m/s
15
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
Re
Cr
Isotopes
Known Isotopes
33
6
21
18
Electronegativity
Pauling Electronegativity
1.90
11
1.66
18
Sanderson Electronegativity
Not Available
1.66
14
Allred Rochow Electronegativity
1.46
15
1.56
10
Allen Electronegativity
1.60
21
1.65
19
Electropositivity
Pauling Electropositivity
2.10
99+
2.34
36
Ionization Energies
1st Energy Level
760.00 kJ/mol
20
26,130.00 kJ/mol
1
2nd Energy Level
1,260.00 kJ/mol
99+
28,750.00 kJ/mol
1
3rd Energy Level
2,510.00 kJ/mol
99+
34,230.00 kJ/mol
1
4th Energy Level
3,640.00 kJ/mol
99+
37,066.00 kJ/mol
1
5th Energy Level
Not Available
97,510.00 kJ/mol
1
6th Energy Level
Not Available
105,800.00 kJ/mol
1
7th Energy level
Not Available
114,300.00 kJ/mol
1
8th Energy Level
Not Available
125,300.00 kJ/mol
1
9th Energy Level
Not Available
134,700.00 kJ/mol
1
10th Energy Level
Not Available
144,300.00 kJ/mol
1
11th Energy Level
Not Available
26,130.00 kJ/mol
12
12th Energy Level
Not Available
28,750.00 kJ/mol
13
13th Energy Level
Not Available
34,230.00 kJ/mol
10
14th Energy Level
Not Available
37,066.00 kJ/mol
12
15th Energy Level
Not Available
97,510.00 kJ/mol
1
16th Energy Level
Not Available
105,800.00 kJ/mol
2
17th Energy Level
Not Available
114,300.00 kJ/mol
3
18th Energy Level
Not Available
125,300.00 kJ/mol
4
19th Energy Level
Not Available
134,700.00 kJ/mol
5
20th Energy Level
Not Available
144,300.00 kJ/mol
7
21st Energy Level
Not Available
157,700.00 kJ/mol
7
22nd Energy Level
Not Available
166,090.00 kJ/mol
6
Electrochemical Equivalent
0.99 g/amp-hr
99+
0.32 g/amp-hr
99+
Electron Work Function
4.96 eV
7
4.50 eV
14
Other Chemical Properties
Corrosion, Ionization, Radioactive Isotopes, Solubility
Anti Corrosion, Chemical Stability, Ionization, Radioactive Isotopes, Solubility
Atomic Properties
Atomic Number
75
99+
24
99+
Electron Configuration
[Xe] 4f14 5d5 6s2
[Ar] 3d5 4s1
Crystal Structure
Hexagonal Close Packed (HCP)
Body Centered Cubic (BCC)
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
BCC-Crystal-Structure-.jpg#100
Atom
Number of Protons
75
40
24
99+
Number of Neutrons
111
26
28
99+
Number of Electrons
75
40
24
99+
Radius of an Atom
Atomic Radius
137.00 pm
40
128.00 pm
99+
Covalent Radius
151.00 pm
34
139.00 pm
99+
Van der Waals Radius
200.00 pm
28
200.00 pm
28
Atomic Weight
186.21 amu
36
52.00 amu
99+
Atomic Volume
8.85 cm3/mol
99+
7.23 cm3/mol
99+
Adjacent Atomic Numbers
Valence Electron Potential
180.00 (-eV)
3
170.00 (-eV)
4
Lattice Constant
276.10 pm
99+
291.00 pm
99+
Lattice Angles
π/2, π/2, 2 π/3
π/2, π/2, π/2
Lattice C/A Ratio
1.62
3
Not Available
Mechanical Properties
Density
Density At Room Temperature
21.02 g/cm3
12
7.19 g/cm3
99+
Density When Liquid (at m.p.)
18.90 g/cm3
4
6.30 g/cm3
40
Tensile Strength
1,070.00 MPa
3
689.00 MPa
7
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 1000 K
Not Available
0.00 (Pa)
24
Vapor Pressure at 2000 K
0.00 (Pa)
29
774.00 (Pa)
1
Elasticity properties
Shear Modulus
178.00 GPa
3
115.00 GPa
9
Bulk Modulus
370.00 GPa
2
160.00 GPa
11
Young's Modulus
463.00 GPa
2
279.00 GPa
8
Poisson Ratio
0.30
14
0.21
32
Other Mechanical Properties
Ductile, Malleable
NA
Magnetic Properties
Magnetic Characteristics
Specific Gravity
21.02
5
7.19
99+
Magnetic Ordering
Paramagnetic
Antiferromagnetic
Electrical Properties
Electrical Property
Conductor
NA
Resistivity
193.00 nΩ·m
20
125.00 nΩ·m
27
Electrical Conductivity
0.05 106/cm Ω
33
0.08 106/cm Ω
25
Electron Affinity
14.50 kJ/mol
35
64.30 kJ/mol
15
Thermal Properties
Specific Heat
0.13 J/(kg K)
39
0.45 J/(kg K)
12
Molar Heat Capacity
25.48 J/mol·K
38
23.35 J/mol·K
99+
Thermal Conductivity
48.00 W/m·K
31
93.90 W/m·K
17
Critical Temperature
Not Available
Not Available
Thermal Expansion
6.20 µm/(m·K)
99+
4.90 µm/(m·K)
99+
Enthalpy
Enthalpy of Vaporization
707.10 kJ/mol
3
348.80 kJ/mol
24
Enthalpy of Fusion
33.05 kJ/mol
2
15.31 kJ/mol
20
Enthalpy of Atomization
791.00 kJ/mol
2
397.50 kJ/mol
21
Standard Molar Entropy
36.90 J/mol.K
99+
23.80 J/mol.K
99+
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