Hafnium vs Cobalt
Periodic Table
Symbol
Hf
Co
Group Number
4
14
9
9
Period Number
6
4
Block
d block
d block
Element Family
Transition Metal
Transition Metal
CAS Number
7440586
30
7440484
38
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.
- The main source of Cobalt is as a by-product of copper and nickel metal mining.
- Cobalt metal can be obtained from other elements like Oxygen, Sulfur and Arsenic.
- It s also used in electroplating process as it exhibits anti cession properties.
Sources
By-product Zirconium Refining
Found in Compounds, Mining, Ores of Minerals
History
Who Discovered
Dirk Coster and George de Hevesy
Georg Brandt
Discovery
In 1922
In 1732
Abundance
Abundance In Universe
7 * 10-8 %
25
3 * 10-4 %
9
Abundance In Sun
~0.0000001 %
26
~0.0004 %
9
Abundance In Meteorites
0.00 %
37
0.06 %
10
Abundance In Earth's Crust
0.00 %
31
0.00 %
21
Abundance In Oceans
0.00 %
27
0.00 %
20
Abundance In Humans
Not Available
0.00 %
17
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.
- Its alloys with aluminum and nickel are used to make powerful magnets.
- Few other alloys exhibit high-temperature strength and hence they are used in Turbines of Jet and Gas engine.
Industrial Uses
Ammunition Industry
Chemical Industry, Electrical Industry, Electronic Industry
Medical Uses
NA
Pharmaceutical Industry
Other Uses
Alloys, In Nuclear Reactors, Nuclear Research, Research Purposes
Alloys
Biological Properties
Toxicity
Toxic
Toxic
Present in Human Body
No
Yes
In Blood
Not Available
0.04 Blood/mg dm-3
18
In Bone
Not Available
0.04 p.p.m.
27
Physical Properties
Melting Point
2,150.00 °C
10
1,495.00 °C
29
Boiling Point
5,400.00 °C
5
2,870.00 °C
34
Appearance
Physical State
Solid
Solid
Color
Gray
Gray
Luster
Metallic
Metallic
Hardness
Mohs Hardness
5.50
7
5.00
8
Brinell Hardness
1,450.00 MPa
6
470.00 MPa
26
Vickers Hardness
1,520.00 MPa
5
1,043.00 MPa
11
Speed of Sound
3,010.00 m/s
27
4,720.00 m/s
14
Optical Properties
Reflectivity
Not Available
67.00 %
11
Allotropes
No
Yes
α Allotropes
Not Available
α-Cobalt
β Allotropes
Not Available
β-Cobalt
γ Allotropes
Not Available
Not Available
Chemical Properties
Chemical Formula
Hf
Co
Isotopes
Known Isotopes
32
7
26
13
Electronegativity
Pauling Electronegativity
1.30
32
1.88
12
Sanderson Electronegativity
Not Available
2.56
1
Allred Rochow Electronegativity
1.23
25
1.70
5
Allen Electronegativity
1.16
37
1.84
10
Electropositivity
Pauling Electropositivity
2.70
22
2.12
99+
Ionization Energies
1st Energy Level
658.50 kJ/mol
40
760.40 kJ/mol
19
2nd Energy Level
1,440.00 kJ/mol
99+
1,648.00 kJ/mol
31
3rd Energy Level
2,250.00 kJ/mol
99+
3,232.00 kJ/mol
22
4th Energy Level
3,216.00 kJ/mol
99+
4,950.00 kJ/mol
19
5th Energy Level
Not Available
7,670.00 kJ/mol
12
6th Energy Level
Not Available
9,840.00 kJ/mol
12
7th Energy level
Not Available
12,440.00 kJ/mol
11
8th Energy Level
Not Available
15,230.00 kJ/mol
12
9th Energy Level
Not Available
17,959.00 kJ/mol
13
10th Energy Level
Not Available
26,570.00 kJ/mol
7
11th Energy Level
Not Available
29,400.00 kJ/mol
8
12th Energy Level
Not Available
32,400.00 kJ/mol
8
13th Energy Level
Not Available
36,600.00 kJ/mol
8
14th Energy Level
Not Available
39,700.00 kJ/mol
9
15th Energy Level
Not Available
42,800.00 kJ/mol
12
16th Energy Level
Not Available
49,396.00 kJ/mol
11
17th Energy Level
Not Available
52,737.00 kJ/mol
13
18th Energy Level
Not Available
134,810.00 kJ/mol
1
19th Energy Level
Not Available
145,170.00 kJ/mol
2
20th Energy Level
Not Available
154,700.00 kJ/mol
4
21st Energy Level
Not Available
167,400.00 kJ/mol
4
22nd Energy Level
Not Available
178,100.00 kJ/mol
3
23rd Energy Level
Not Available
189,300.00 kJ/mol
3
Electrochemical Equivalent
1.66 g/amp-hr
99+
1.10 g/amp-hr
99+
Electron Work Function
3.90 eV
27
5.00 eV
5
Other Chemical Properties
Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
Chemical Stability, Ionization
Atomic Properties
Atomic Number
72
99+
22
99+
Electron Configuration
[Xe] 4f14 5d2 6s2
[Ar] 3d2 4s2
Crystal Structure
Hexagonal Close Packed (HCP)
Hexagonal Close Packed (HCP)
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
HCP-Crystal-Structure-of-Cobalt.jpg#100
Atom
Number of Protons
72
99+
22
99+
Number of Neutrons
106
29
26
99+
Number of Electrons
72
99+
22
99+
Radius of an Atom
Atomic Radius
159.00 pm
28
147.00 pm
34
Covalent Radius
175.00 pm
23
160.00 pm
30
Van der Waals Radius
200.00 pm
28
200.00 pm
28
Atomic Weight
178.49 amu
39
47.87 amu
99+
Atomic Volume
13.60 cm3/mol
38
10.64 cm3/mol
99+
Adjacent Atomic Numbers
Valence Electron Potential
81.00 (-eV)
16
95.20 (-eV)
10
Lattice Constant
319.64 pm
99+
295.08 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
Not Available
Mechanical Properties
Density
Density At Room Temperature
13.31 g/cm3
26
4.51 g/cm3
99+
Density When Liquid (at m.p.)
12.00 g/cm3
12
4.11 g/cm3
99+
Tensile Strength
445.00 MPa
8
434.00 MPa
9
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 2000 K
0.00 (Pa)
24
0.98 (Pa)
14
Elasticity properties
Shear Modulus
30.00 GPa
23
44.00 GPa
17
Bulk Modulus
110.00 GPa
15
110.00 GPa
15
Young's Modulus
78.00 GPa
25
116.00 GPa
18
Poisson Ratio
0.37
7
0.32
12
Other Mechanical Properties
Ductile, Malleable
Ductile
Magnetic Properties
Magnetic Characteristics
Specific Gravity
13.31
18
4,500.00
1
Magnetic Ordering
Paramagnetic
Paramagnetic
Electrical Properties
Electrical Property
Conductor
Poor Conductor
Resistivity
331.00 nΩ·m
14
420.00 nΩ·m
12
Electrical Conductivity
0.03 106/cm Ω
39
0.02 106/cm Ω
99+
Electron Affinity
0.00 kJ/mol
40
7.60 kJ/mol
37
Thermal Properties
Specific Heat
0.14 J/(kg K)
37
0.52 J/(kg K)
9
Molar Heat Capacity
25.73 J/mol·K
36
25.06 J/mol·K
99+
Thermal Conductivity
23.00 W/m·K
99+
21.90 W/m·K
99+
Critical Temperature
Not Available
Not Available
Thermal Expansion
5.90 µm/(m·K)
99+
8.60 µm/(m·K)
99+
Enthalpy
Enthalpy of Vaporization
661.10 kJ/mol
5
429.00 kJ/mol
15
Enthalpy of Fusion
25.10 kJ/mol
8
15.48 kJ/mol
19
Enthalpy of Atomization
703.00 kJ/mol
5
468.60 kJ/mol
15
Standard Molar Entropy
43.60 J/mol.K
34
27.30 J/mol.K
99+
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