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Osmium Iridium Comparison


Iridium Osmium comparison


Periodic Table

Symbol
Os   
Ir   

Group Number
8   
10
9   
9

Period Number
6   
6   

Block
d block   
d block   

Element Family
Transition Metal   
Transition Metal   

CAS Number
7440042   
99+
7439885   
99+

Space Group Name
P63/mmc   
Fm_ 3m   

Space Group Number
194.00   
5
225.00   
2

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.
  
  • Iridium element occurs as natural alloys of Platinum and Osmium.
  • Iridium element is known as the most corrosion resistance metal .
  

Sources
Found As a By-product, Found in Minerals, Mining   
Found in Minerals, Mining, Ores of Minerals   

History
  
  

Who Discovered
Smithson Tennant   
Smithson Tennant   

Discovery
In 1803   
In 1803   

Abundance
  
  

Abundance In Universe
3 * 10-7 %   
21
2 * 10-7 %   
22

Abundance In Sun
~0.0000002 %   
25
~0.0000002 %   
25

Abundance In Meteorites
0.00 %   
28
0.00 %   
29

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

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.
  
  • Iridium has an anti corrosion properties and it is used in special alloy with Osmium metal and that alloy is used in pen tips and compass bearings.
  

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

Medical Uses
NA   
NA   

Other Uses
Alloys   
Alloys   

Biological Properties
  
  

Toxicity
Highly Toxic   
Toxic   

Present in Human Body
No   
Yes   

Physical Properties

Melting Point
3,045.00 °C   
3
2,410.00 °C   
7

Boiling Point
5,027.00 °C   
6
4,527.00 °C   
10

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silvery Bluish-Gray   
Silvery White   

Luster
Metallic   
Metallic   

Hardness
  
  

Mohs Hardness
7.00   
3
6.50   
5

Brinell Hardness
3,490.00 MPa   
1
1,670.00 MPa   
5

Vickers Hardness
Not Available   
1,760.00 MPa   
3

Speed of Sound
4,940.00 m/s   
11
4,825.00 m/s   
13

Optical Properties
  
  

Reflectivity
Not Available   
78.00 %   
6

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   
Ir   

Isotopes
  
  

Known Isotopes
35   
4
34   
5

Electronegativity
  
  

Pauling Electronegativity
2.20   
4
2.20   
4

Allred Rochow Electronegativity
1.52   
12
1.55   
11

Allen Electronegativity
1.65   
19
1.68   
17

Electropositivity
  
  

Pauling Electropositivity
1.80   
99+
1.80   
99+

Ionization Energies
  
  

1st Energy Level
840.00 kJ/mol   
12
880.00 kJ/mol   
9

2nd Energy Level
1,309.80 kJ/mol   
99+
1,600.00 kJ/mol   
35

3rd Energy Level
1,600.00 kJ/mol   
99+
Not Available   

Electrochemical Equivalent
1.77 g/amp-hr   
38
1.14 g/amp-hr   
99+

Electron Work Function
4.83 eV   
8
4.55 eV   
13

Other Chemical Properties
Chemical Stability, Ionization, Solubility   
Flammable, Ionization, Radioactive Isotopes, Radioactivity   

Atomic Properties

Atomic Number
76   
40
77   
39

Electron Configuration
[Xe] 4f14 5d6 6s2   
[Xe] 4f14 5d7 6s2   

Crystal Structure
Hexagonal Close Packed (HCP)   
Face Centered Cubic (FCC)   

Crystal Lattice
BCC-Crystal-Structure-.jpg#100   
FCC-Crystal-Structure-of-Iridium.jpg#100   

Atom
  
  

Number of Protons
76   
39
74   
99+

Number of Neutrons
114   
25
110   
27

Number of Electrons
76   
39
74   
99+

Radius of an Atom
  
  

Atomic Radius
133.80 pm   
99+
136.00 pm   
99+

Covalent Radius
Not Available   
141.00 pm   
99+

Van der Waals Radius
216.00 pm   
24
202.00 pm   
27

Atomic Weight
190.23 amu   
35
192.22 amu   
34

Atomic Volume
8.49 cm3/mol   
99+
9.53 cm3/mol   
99+

Adjacent Atomic Numbers
  
  

Previous Element
Rhenium
  
Osmium
  

Next Element
Iridium
  
Platinum
  

Valence Electron Potential
91.40 (-eV)   
12
140.00 (-eV)   
5

Lattice Constant
273.44 pm   
99+
383.90 pm   
26

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

Lattice C/A Ratio
1.58   
14
Not Available   

Mechanical Properties

Density
  
  

Density At Room Temperature
22.59 g/cm3   
9
22.56 g/cm3   
10

Density When Liquid (at m.p.)
20.00 g/cm3   
1
19.00 g/cm3   
3

Tensile Strength
1,000.00 MPa   
4
2,000.00 MPa   
2

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Vapor Pressure at 2000 K
0.00 (Pa)   
28
0.00 (Pa)   
25

Elasticity properties
  
  

Shear Modulus
222.00 GPa   
1
210.00 GPa   
2

Bulk Modulus
462.00 GPa   
1
320.00 GPa   
3

Young's Modulus
Not Available   
528.00 GPa   
1

Poisson Ratio
0.25   
24
0.26   
22

Other Mechanical Properties
Ductile   
NA   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
22.57   
2
21.78   
3

Magnetic Ordering
Paramagnetic   
Paramagnetic   

Electrical Properties
  
  

Electrical Property
Conductor   
Conductor   

Resistivity
81.20 nΩ·m   
35
47.10 nΩ·m   
99+

Electrical Conductivity
0.11 106/cm Ω   
18
0.19 106/cm Ω   
10

Electron Affinity
106.10 kJ/mol   
9
151.00 kJ/mol   
4

Thermal Properties

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

Molar Heat Capacity
24.70 J/mol·K   
99+
25.10 J/mol·K   
99+

Thermal Conductivity
87.60 W/m·K   
19
147.00 W/m·K   
10

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
5.10 µm/(m·K)   
99+
6.40 µm/(m·K)   
99+

Enthalpy
  
  

Enthalpy of Vaporization
627.60 kJ/mol   
7
799.10 kJ/mol   
1

Enthalpy of Fusion
29.30 kJ/mol   
4
35.23 kJ/mol   
1

Enthalpy of Atomization
669.00 kJ/mol   
6
837.00 kJ/mol   
1

Standard Molar Entropy
32.60 J/mol.K   
99+
35.50 J/mol.K   
99+

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