Osmium vs Hafnium
Periodic Table
Symbol
Os
Hf
Group Number
8
10
4
14
Period Number
6
6
Block
d block
d block
Element Family
Transition Metal
Transition Metal
CAS Number
7440042
99+
7440586
30
Space Group Name
P63/mmc
P63/mmc
Space Group Number
194.00
5
194.00
5
Facts
Interesting Facts
- Osmium metal does not oxidize in air unless it is heated.
- But if it heated den it forms Osmium Tetroxide, which is highly toxic.
- Hafnium metal is highly reactive, hence not found free in nature.
- Hafnium metal as predicated after Mendeleev finished his periodic table.
Sources
Found As a By-product, Found in Minerals, Mining
By-product Zirconium Refining
History
Who Discovered
Smithson Tennant
Dirk Coster and George de Hevesy
Discovery
In 1803
In 1922
Abundance
Abundance In Universe
3 * 10-7 %
21
7 * 10-8 %
25
Abundance In Sun
~0.0000002 %
25
~0.0000001 %
26
Abundance In Meteorites
0.00 %
28
0.00 %
37
Abundance In Earth's Crust
0.00 %
99+
0.00 %
31
Abundance In Oceans
Not Available
0.00 %
27
Uses
Uses & Benefits
- Its has very limited uses and its alloys are very hard and are used in the manufacturing of pen tips, pivots, needles and electrical contacts.
- It is also used as industrial catalyst to speed up the chemical reaction.
- 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, Electrical Industry, Electronic Industry
Ammunition Industry
Medical Uses
NA
NA
Other Uses
Alloys
Alloys, In Nuclear Reactors, Nuclear Research, Research Purposes
Biological Properties
Toxicity
Highly Toxic
Toxic
Present in Human Body
No
No
Physical Properties
Melting Point
3,045.00 °C
3
2,150.00 °C
10
Boiling Point
5,027.00 °C
6
5,400.00 °C
5
Appearance
Physical State
Solid
Solid
Color
Silvery Bluish-Gray
Gray
Luster
Metallic
Metallic
Hardness
Mohs Hardness
7.00
3
5.50
7
Brinell Hardness
3,490.00 MPa
1
1,450.00 MPa
6
Vickers Hardness
Not Available
1,520.00 MPa
5
Speed of Sound
4,940.00 m/s
11
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
Os
Hf
Isotopes
Known Isotopes
35
4
32
7
Electronegativity
Pauling Electronegativity
2.20
4
1.30
32
Allred Rochow Electronegativity
1.52
12
1.23
25
Allen Electronegativity
1.65
19
1.16
37
Electropositivity
Pauling Electropositivity
1.80
99+
2.70
22
Ionization Energies
1st Energy Level
840.00 kJ/mol
12
658.50 kJ/mol
40
2nd Energy Level
1,309.80 kJ/mol
99+
1,440.00 kJ/mol
99+
3rd Energy Level
1,600.00 kJ/mol
99+
2,250.00 kJ/mol
99+
4th Energy Level
Not Available
3,216.00 kJ/mol
99+
Electrochemical Equivalent
1.77 g/amp-hr
38
1.66 g/amp-hr
99+
Electron Work Function
4.83 eV
8
3.90 eV
27
Other Chemical Properties
Chemical Stability, Ionization, Solubility
Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
Atomic Properties
Atomic Number
76
40
72
99+
Electron Configuration
[Xe] 4f14 5d6 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
76
39
72
99+
Number of Neutrons
114
25
106
29
Number of Electrons
76
39
72
99+
Radius of an Atom
Atomic Radius
133.80 pm
99+
159.00 pm
28
Covalent Radius
Not Available
175.00 pm
23
Van der Waals Radius
216.00 pm
24
200.00 pm
28
Atomic Weight
190.23 amu
35
178.49 amu
39
Atomic Volume
8.49 cm3/mol
99+
13.60 cm3/mol
38
Adjacent Atomic Numbers
Valence Electron Potential
91.40 (-eV)
12
81.00 (-eV)
16
Lattice Constant
273.44 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
1.58
14
1.58
12
Mechanical Properties
Density
Density At Room Temperature
22.59 g/cm3
9
13.31 g/cm3
26
Density When Liquid (at m.p.)
20.00 g/cm3
1
12.00 g/cm3
12
Tensile Strength
1,000.00 MPa
4
445.00 MPa
8
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 2000 K
0.00 (Pa)
28
0.00 (Pa)
24
Elasticity properties
Shear Modulus
222.00 GPa
1
30.00 GPa
23
Bulk Modulus
462.00 GPa
1
110.00 GPa
15
Young's Modulus
Not Available
78.00 GPa
25
Poisson Ratio
0.25
24
0.37
7
Other Mechanical Properties
Ductile
Ductile, Malleable
Magnetic Properties
Magnetic Characteristics
Specific Gravity
22.57
2
13.31
18
Magnetic Ordering
Paramagnetic
Paramagnetic
Electrical Properties
Electrical Property
Conductor
Conductor
Resistivity
81.20 nΩ·m
35
331.00 nΩ·m
14
Electrical Conductivity
0.11 106/cm Ω
18
0.03 106/cm Ω
39
Electron Affinity
106.10 kJ/mol
9
0.00 kJ/mol
40
Thermal Properties
Specific Heat
0.13 J/(kg K)
39
0.14 J/(kg K)
37
Molar Heat Capacity
24.70 J/mol·K
99+
25.73 J/mol·K
36
Thermal Conductivity
87.60 W/m·K
19
23.00 W/m·K
99+
Critical Temperature
Not Available
Not Available
Thermal Expansion
5.10 µm/(m·K)
99+
5.90 µm/(m·K)
99+
Enthalpy
Enthalpy of Vaporization
627.60 kJ/mol
7
661.10 kJ/mol
5
Enthalpy of Fusion
29.30 kJ/mol
4
25.10 kJ/mol
8
Enthalpy of Atomization
669.00 kJ/mol
6
703.00 kJ/mol
5
Standard Molar Entropy
32.60 J/mol.K
99+
43.60 J/mol.K
34
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