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Rhenium Hafnium Comparison


Hafnium Rhenium comparison


Periodic Table

Symbol
Re   
Hf   

Group Number
7   
11
4   
14

Period Number
6   
6   

Block
d block   
d block   

Element Family
Transition Metal   
Transition Metal   

CAS Number
7440155   
99+
7440586   
30

Space Group Name
P63/mmc   
P63/mmc   

Space Group Number
194.00   
5
194.00   
5

Facts

Interesting Facts
  • Chemical properties of Rhenium are similar to Manganese.
  • Rhenium metal is created while refining Molybdenum.
  
  • Hafnium metal is highly reactive, hence not found free in nature.
  • Hafnium metal as predicated after Mendeleev finished his periodic table.
  

Sources
Found in Minerals, Mining, Ores of Minerals   
By-product Zirconium Refining   

History
  
  

Who Discovered
Masataka Ogawa   
Dirk Coster and George de Hevesy   

Discovery
In 1908   
In 1922   

Abundance
  
  

Abundance In Universe
2 * 10-8 %   
29
7 * 10-8 %   
25

Abundance In Sun
~0.00000001 %   
29
~0.0000001 %   
26

Abundance In Meteorites
0.00 %   
99+
0.00 %   
37

Abundance In Earth's Crust
0.00 %   
99+
0.00 %   
31

Abundance In Oceans
0.00 %   
34
0.00 %   
27

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 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.
  

Industrial Uses
Aerospace Industry, Automobile Industry, Chemical Industry, Electrical Industry, Electronic Industry   
Ammunition Industry   

Medical Uses
NA   
NA   

Other Uses
Alloys   
Alloys, In Nuclear Reactors, Nuclear Research, Research Purposes   

Biological Properties
  
  

Toxicity
Low Toxic   
Toxic   

Present in Human Body
No   
No   

Physical Properties

Melting Point
3,180.00 °C   
2
2,150.00 °C   
10

Boiling Point
5,627.00 °C   
2
5,400.00 °C   
5

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silvery Gray   
Gray   

Luster
Metallic   
Metallic   

Hardness
  
  

Mohs Hardness
7.00   
3
5.50   
7

Brinell Hardness
1,320.00 MPa   
8
1,450.00 MPa   
6

Vickers Hardness
1,350.00 MPa   
7
1,520.00 MPa   
5

Speed of Sound
4,700.00 m/s   
15
3,010.00 m/s   
27

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   
Hf   

Isotopes
  
  

Known Isotopes
33   
6
32   
7

Electronegativity
  
  

Pauling Electronegativity
1.90   
11
1.30   
32

Allred Rochow Electronegativity
1.46   
15
1.23   
25

Allen Electronegativity
1.60   
21
1.16   
37

Electropositivity
  
  

Pauling Electropositivity
2.10   
99+
2.70   
22

Ionization Energies
  
  

1st Energy Level
760.00 kJ/mol   
20
658.50 kJ/mol   
40

2nd Energy Level
1,260.00 kJ/mol   
99+
1,440.00 kJ/mol   
99+

3rd Energy Level
2,510.00 kJ/mol   
99+
2,250.00 kJ/mol   
99+

4th Energy Level
3,640.00 kJ/mol   
99+
3,216.00 kJ/mol   
99+

Electrochemical Equivalent
0.99 g/amp-hr   
99+
1.66 g/amp-hr   
99+

Electron Work Function
4.96 eV   
7
3.90 eV   
27

Other Chemical Properties
Corrosion, Ionization, Radioactive Isotopes, Solubility   
Anti Corrosion, Ionization, Radioactive Isotopes, Solubility   

Atomic Properties

Atomic Number
75   
99+
72   
99+

Electron Configuration
[Xe] 4f14 5d5 6s2   
[Xe] 4f14 5d2 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
75   
40
72   
99+

Number of Neutrons
111   
26
106   
29

Number of Electrons
75   
40
72   
99+

Radius of an Atom
  
  

Atomic Radius
137.00 pm   
40
159.00 pm   
28

Covalent Radius
151.00 pm   
34
175.00 pm   
23

Van der Waals Radius
200.00 pm   
28
200.00 pm   
28

Atomic Weight
186.21 amu   
36
178.49 amu   
39

Atomic Volume
8.85 cm3/mol   
99+
13.60 cm3/mol   
38

Adjacent Atomic Numbers
  
  

Previous Element
Tungsten
  
Lutetium
  

Next Element
Osmium
  
Tantalum
  

Valence Electron Potential
180.00 (-eV)   
3
81.00 (-eV)   
16

Lattice Constant
276.10 pm   
99+
319.64 pm   
99+

Lattice Angles
π/2, π/2, 2 π/3   
π/2, π/2, 2 π/3   

Lattice C/A Ratio
1.62   
3
1.58   
12

Mechanical Properties

Density
  
  

Density At Room Temperature
21.02 g/cm3   
12
13.31 g/cm3   
26

Density When Liquid (at m.p.)
18.90 g/cm3   
4
12.00 g/cm3   
12

Tensile Strength
1,070.00 MPa   
3
445.00 MPa   
8

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Vapor Pressure at 2000 K
0.00 (Pa)   
29
0.00 (Pa)   
24

Elasticity properties
  
  

Shear Modulus
178.00 GPa   
3
30.00 GPa   
23

Bulk Modulus
370.00 GPa   
2
110.00 GPa   
15

Young's Modulus
463.00 GPa   
2
78.00 GPa   
25

Poisson Ratio
0.30   
14
0.37   
7

Other Mechanical Properties
Ductile, Malleable   
Ductile, Malleable   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
21.02   
5
13.31   
18

Magnetic Ordering
Paramagnetic   
Paramagnetic   

Electrical Properties
  
  

Electrical Property
Conductor   
Conductor   

Resistivity
193.00 nΩ·m   
20
331.00 nΩ·m   
14

Electrical Conductivity
0.05 106/cm Ω   
33
0.03 106/cm Ω   
39

Electron Affinity
14.50 kJ/mol   
35
0.00 kJ/mol   
40

Thermal Properties

Specific Heat
0.13 J/(kg K)   
39
0.14 J/(kg K)   
37

Molar Heat Capacity
25.48 J/mol·K   
38
25.73 J/mol·K   
36

Thermal Conductivity
48.00 W/m·K   
31
23.00 W/m·K   
99+

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
6.20 µm/(m·K)   
99+
5.90 µm/(m·K)   
99+

Enthalpy
  
  

Enthalpy of Vaporization
707.10 kJ/mol   
3
661.10 kJ/mol   
5

Enthalpy of Fusion
33.05 kJ/mol   
2
25.10 kJ/mol   
8

Enthalpy of Atomization
791.00 kJ/mol   
2
703.00 kJ/mol   
5

Standard Molar Entropy
36.90 J/mol.K   
99+
43.60 J/mol.K   
34

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