Hafnium vs Rhenium
Periodic Table
Symbol
Hf
Re
Group Number
4
14
7
11
Period Number
6
6
Block
d block
d block
Element Family
Transition Metal
Transition Metal
CAS Number
7440586
30
7440155
99+
Space Group Name
P63/mmc
P63/mmc
Space Group Number
194.00
5
194.00
5
Facts
Interesting Facts
- Hafnium metal is highly reactive, hence not found free in nature.
- Hafnium metal as predicated after Mendeleev finished his periodic table.
- Chemical properties of Rhenium are similar to Manganese.
- Rhenium metal is created while refining Molybdenum.
Sources
By-product Zirconium Refining
Found in Minerals, Mining, Ores of Minerals
History
Who Discovered
Dirk Coster and George de Hevesy
Masataka Ogawa
Discovery
In 1922
In 1908
Abundance
Abundance In Universe
7 * 10-8 %
25
2 * 10-8 %
29
Abundance In Sun
~0.0000001 %
26
~0.00000001 %
29
Abundance In Meteorites
0.00 %
37
0.00 %
99+
Abundance In Earth's Crust
0.00 %
31
0.00 %
99+
Abundance In Oceans
0.00 %
27
0.00 %
34
Uses
Uses & Benefits
- It has an ability to absorb neutrons and hence it is used to make control rods in nuclear submarines. And this metal is also used in Plasma welding torches.
- It alloys with iron, titanium and niobium are very useful.
- 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.
Industrial Uses
Ammunition Industry
Aerospace Industry, Automobile Industry, Chemical Industry, Electrical Industry, Electronic Industry
Medical Uses
NA
NA
Other Uses
Alloys, In Nuclear Reactors, Nuclear Research, Research Purposes
Alloys
Biological Properties
Toxicity
Toxic
Low Toxic
Present in Human Body
No
No
Physical Properties
Melting Point
2,150.00 °C
10
3,180.00 °C
2
Boiling Point
5,400.00 °C
5
5,627.00 °C
2
Appearance
Physical State
Solid
Solid
Color
Gray
Silvery Gray
Luster
Metallic
Metallic
Hardness
Mohs Hardness
5.50
7
7.00
3
Brinell Hardness
1,450.00 MPa
6
1,320.00 MPa
8
Vickers Hardness
1,520.00 MPa
5
1,350.00 MPa
7
Speed of Sound
3,010.00 m/s
27
4,700.00 m/s
15
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
Hf
Re
Isotopes
Known Isotopes
32
7
33
6
Electronegativity
Pauling Electronegativity
1.30
32
1.90
11
Allred Rochow Electronegativity
1.23
25
1.46
15
Allen Electronegativity
1.16
37
1.60
21
Electropositivity
Pauling Electropositivity
2.70
22
2.10
99+
Ionization Energies
1st Energy Level
658.50 kJ/mol
40
760.00 kJ/mol
20
2nd Energy Level
1,440.00 kJ/mol
99+
1,260.00 kJ/mol
99+
3rd Energy Level
2,250.00 kJ/mol
99+
2,510.00 kJ/mol
99+
4th Energy Level
3,216.00 kJ/mol
99+
3,640.00 kJ/mol
99+
Electrochemical Equivalent
1.66 g/amp-hr
99+
0.99 g/amp-hr
99+
Electron Work Function
3.90 eV
27
4.96 eV
7
Other Chemical Properties
Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
Corrosion, Ionization, Radioactive Isotopes, Solubility
Atomic Properties
Atomic Number
72
99+
75
99+
Electron Configuration
[Xe] 4f14 5d2 6s2
[Xe] 4f14 5d5 6s2
Crystal Structure
Hexagonal Close Packed (HCP)
Hexagonal Close Packed (HCP)
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
BCC-Crystal-Structure-.jpg#100
Atom
Number of Protons
72
99+
75
40
Number of Neutrons
106
29
111
26
Number of Electrons
72
99+
75
40
Radius of an Atom
Atomic Radius
159.00 pm
28
137.00 pm
40
Covalent Radius
175.00 pm
23
151.00 pm
34
Van der Waals Radius
200.00 pm
28
200.00 pm
28
Atomic Weight
178.49 amu
39
186.21 amu
36
Atomic Volume
13.60 cm3/mol
38
8.85 cm3/mol
99+
Adjacent Atomic Numbers
Valence Electron Potential
81.00 (-eV)
16
180.00 (-eV)
3
Lattice Constant
319.64 pm
99+
276.10 pm
99+
Lattice Angles
π/2, π/2, 2 π/3
π/2, π/2, 2 π/3
Lattice C/A Ratio
1.58
12
1.62
3
Mechanical Properties
Density
Density At Room Temperature
13.31 g/cm3
26
21.02 g/cm3
12
Density When Liquid (at m.p.)
12.00 g/cm3
12
18.90 g/cm3
4
Tensile Strength
445.00 MPa
8
1,070.00 MPa
3
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 2000 K
0.00 (Pa)
24
0.00 (Pa)
29
Elasticity properties
Shear Modulus
30.00 GPa
23
178.00 GPa
3
Bulk Modulus
110.00 GPa
15
370.00 GPa
2
Young's Modulus
78.00 GPa
25
463.00 GPa
2
Poisson Ratio
0.37
7
0.30
14
Other Mechanical Properties
Ductile, Malleable
Ductile, Malleable
Magnetic Properties
Magnetic Characteristics
Specific Gravity
13.31
18
21.02
5
Magnetic Ordering
Paramagnetic
Paramagnetic
Electrical Properties
Electrical Property
Conductor
Conductor
Resistivity
331.00 nΩ·m
14
193.00 nΩ·m
20
Electrical Conductivity
0.03 106/cm Ω
39
0.05 106/cm Ω
33
Electron Affinity
0.00 kJ/mol
40
14.50 kJ/mol
35
Thermal Properties
Specific Heat
0.14 J/(kg K)
37
0.13 J/(kg K)
39
Molar Heat Capacity
25.73 J/mol·K
36
25.48 J/mol·K
38
Thermal Conductivity
23.00 W/m·K
99+
48.00 W/m·K
31
Critical Temperature
Not Available
Not Available
Thermal Expansion
5.90 µm/(m·K)
99+
6.20 µm/(m·K)
99+
Enthalpy
Enthalpy of Vaporization
661.10 kJ/mol
5
707.10 kJ/mol
3
Enthalpy of Fusion
25.10 kJ/mol
8
33.05 kJ/mol
2
Enthalpy of Atomization
703.00 kJ/mol
5
791.00 kJ/mol
2
Standard Molar Entropy
43.60 J/mol.K
34
36.90 J/mol.K
99+
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