Symbol
Hf
Co
Group Number
49
0
17
👆🏻
Period Number
64
2
7
👆🏻
Block
d block
d block
Element Family
Transition Metal
Transition Metal
CAS Number
74405867440484
7429905
54386242
👆🏻
Space Group Name
P63/mmc
P63/mmc
Space Group Number
194.00194.00
11
276
👆🏻
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
0.00 %0.00 %
0
0.11
👆🏻
Abundance In Sun
0.00 %0.00 %
0
0.1
👆🏻
Abundance In Meteorites
0.00 %0.06 %
0
22
👆🏻
Abundance In Earth's Crust
0.00 %0.00 %
1E-37
8.1
👆🏻
Abundance In Oceans
0.00 %0.00 %
0
1.1
👆🏻
Abundance In Humans
0.00 %0.00 %
0
1.4
👆🏻
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
-
Pharmaceutical Industry
Other Uses
Alloys, In Nuclear Reactors, Nuclear Research, Research Purposes
Alloys
Biological Properties
Toxicity
Toxic
Toxic
Present in Human Body
✔
✘
✔
✘
In Blood
0.00 Blood/mg dm-30.04 Blood/mg dm-3
0
1970
👆🏻
In Bone
0.00 p.p.m.0.04 p.p.m.
0
170000
👆🏻
Melting Point
2,150.00 °C1,495.00 °C
-38.83
3410
👆🏻
Boiling Point
5,400.00 °C2,870.00 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
Gray
Gray
Luster
Metallic
Metallic
Hardness
Mohs Hardness
5.505.00
0.2
8.5
👆🏻
Brinell Hardness
1,450.00 MPa470.00 MPa
0.14
3490
👆🏻
Vickers Hardness
1,520.00 MPa1,043.00 MPa
0
3920
👆🏻
Speed of Sound
3,010.00 m/s4,720.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
2.002.50
0.155
3.41
👆🏻
Reflectivity
71.00 %67.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
α-Cobalt
β Allotropes
-
β-Cobalt
γ Allotropes
-
-
Chemical Formula
Hf
Co
Isotopes
Known Isotopes
3226
0
38
👆🏻
Electronegativity
Pauling Electronegativity
1.301.88
0
2.6
👆🏻
Sanderson Electronegativity
1.302.56
0.22
2.56
👆🏻
Allred Rochow Electronegativity
1.231.70
0.86
1.9
👆🏻
Mulliken-Jaffe Electronegativity
1.301.88
0.62
2.48
👆🏻
Allen Electronegativity
1.161.84
0.659
2.7
👆🏻
Electropositivity
Pauling Electropositivity
2.702.12
1.46
3.3
👆🏻
Ionization Energies
1st Energy Level
658.50 kJ/mol760.40 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
1,440.00 kJ/mol1,648.00 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
2,250.00 kJ/mol3,232.00 kJ/mol
392.8
34230
👆🏻
4th Energy Level
3,216.00 kJ/mol4,950.00 kJ/mol
375.7
37066
👆🏻
5th Energy Level
6,585.00 kJ/mol7,670.00 kJ/mol
392
97510
👆🏻
6th Energy Level
6,585.00 kJ/mol9,840.00 kJ/mol
1007
105800
👆🏻
7th Energy level
6,580.00 kJ/mol12,440.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
6,580.00 kJ/mol15,230.00 kJ/mol
730
125300
👆🏻
9th Energy Level
6,585.00 kJ/mol17,959.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
6,590.00 kJ/mol26,570.00 kJ/mol
392
144300
👆🏻
11th Energy Level
6,585.00 kJ/mol29,400.00 kJ/mol
392
169988
👆🏻
12th Energy Level
6,580.00 kJ/mol32,400.00 kJ/mol
0
189368
👆🏻
13th Energy Level
6,580.00 kJ/mol36,600.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
658.50 kJ/mol39,700.00 kJ/mol
380
86450
👆🏻
15th Energy Level
65,800.00 kJ/mol42,800.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
658.50 kJ/mol49,396.00 kJ/mol
375.7
109480
👆🏻
17th Energy Level
658.50 kJ/mol52,737.00 kJ/mol
375.7
122200
👆🏻
18th Energy Level
6,585.00 kJ/mol134,810.00 kJ/mol
0
134810
👆🏻
19th Energy Level
658.50 kJ/mol145,170.00 kJ/mol
375.7
148700
👆🏻
20th Energy Level
658.00 kJ/mol154,700.00 kJ/mol
0
171200
👆🏻
21st Energy Level
658.50 kJ/mol167,400.00 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
658.00 kJ/mol178,100.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
658.50 kJ/mol189,300.00 kJ/mol
357.6
198800
👆🏻
24th Energy Level
658.50 kJ/mol760.40 kJ/mol
297.3
195200
👆🏻
25th Energy Level
658.00 kJ/mol760.40 kJ/mol
0
121900
👆🏻
26th Energy Level
658.50 kJ/mol760.40 kJ/mol
357.6
127700
👆🏻
27th Energy Level
658.50 kJ/mol760.40 kJ/mol
0
133800
👆🏻
28th Energy Level
658.50 kJ/mol760.40 kJ/mol
297.3
139800
👆🏻
29th Energy Level
658.50 kJ/mol760.40 kJ/mol
0
148100
👆🏻
30th Energy Level
658.00 kJ/mol760.40 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
1.66 g/amp-hr1.10 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
3.90 eV5.00 eV
2.14
6
👆🏻
Other Chemical Properties
Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
Chemical Stability, Ionization
Atomic Number
7222
3
117
👆🏻
Electron Configuration
[Xe] 4f14 5d2 6s2
[Ar] 3d2 4s2
Crystal Structure
Hexagonal Close Packed (HCP)
Hexagonal Close Packed (HCP)
Crystal Lattice
Atom
Number of Protons
7222
3
117
👆🏻
Number of Neutrons
10626
4
285
👆🏻
Number of Electrons
7222
3
117
👆🏻
Radius of an Atom
Atomic Radius
159.00 pm147.00 pm
0
348
👆🏻
Covalent Radius
175.00 pm160.00 pm
0
260
👆🏻
Van der Waals Radius
200.00 pm200.00 pm
0
348
👆🏻
Atomic Weight
178.49 amu47.87 amu
6.94
294
👆🏻
Atomic Volume
13.60 cm3/mol10.64 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
81.00 (-eV)95.20 (-eV)
0
392.42
👆🏻
Lattice Constant
319.64 pm295.08 pm
0
891.25
👆🏻
Lattice Angles
π/2, π/2, 2 π/3
π/2, π/2, 2 π/3
Lattice C/A Ratio
1.581.26
0.423
1.9
👆🏻
Density
Density At Room Temperature
13.31 g/cm34.51 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
12.00 g/cm34.11 g/cm3
0.512
41
👆🏻
Tensile Strength
445.00 MPa434.00 MPa
0.1
11000
👆🏻
Viscosity
0.000.00
1.5E-05
0.0035
👆🏻
Vapor Pressure
Vapor Pressure at 1000 K
0.00 (Pa)0.00 (Pa)
0
121
👆🏻
Vapor Pressure at 2000 K
0.00 (Pa)0.98 (Pa)
0
774
👆🏻
Elasticity properties
Shear Modulus
30.00 GPa44.00 GPa
1.3
222
👆🏻
Bulk Modulus
110.00 GPa110.00 GPa
0
462
👆🏻
Young's Modulus
78.00 GPa116.00 GPa
0
528
👆🏻
Poisson Ratio
0.370.32
0.032
0.47
👆🏻
Other Mechanical Properties
Ductile, Malleable
Ductile
Magnetic Characteristics
Specific Gravity
13.314,500.00
0.53
4500
👆🏻
Magnetic Ordering
Paramagnetic
Paramagnetic
Permeability
0.00 H/m0.00 H/m
1.25643E-06
0.0063
👆🏻
Susceptibility
0.000.00
-0.000166
200000
👆🏻
Electrical Properties
Electrical Property
Conductor
Poor Conductor
Resistivity
331.00 nΩ·m420.00 nΩ·m
0.1
961
👆🏻
Electrical Conductivity
0.03 106/cm Ω0.02 106/cm Ω
0
0.63
👆🏻
Electron Affinity
0.00 kJ/mol7.60 kJ/mol
0
222.8
👆🏻
Specific Heat
0.14 J/(kg K)0.52 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
25.73 J/mol·K25.06 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
23.00 W/m·K21.90 W/m·K
0
429
👆🏻
Critical Temperature
2,500.00 K1,768.00 K
26.3
3695
👆🏻
Thermal Expansion
5.90 µm/(m·K)8.60 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
661.10 kJ/mol429.00 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
25.10 kJ/mol15.48 kJ/mol
2.1
35.23
👆🏻
Enthalpy of Atomization
703.00 kJ/mol468.60 kJ/mol
61.5
837
👆🏻
Standard Molar Entropy
43.60 J/mol.K27.30 J/mol.K
9.5
198.1
👆🏻