Symbol
Os
  
Cs
  
Period Number
6
  
6
  
Block
d block
  
s block
  
Element Family
Transition Metal
  
Alkali
  
Space Group Name
P63/mmc
  
Im_ 3m
  
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.
  
Not Available
  
Sources
Found As a By-product, Found in Minerals, Mining
  
Earth's crust, Found in Minerals, Mining, Ores of Minerals
  
History
  
  
Who Discovered
Smithson Tennant
  
Robert Bunsen and Gustav Kirchhoff
  
Discovery
In 1803
  
In 1860
  
Abundance
  
  
Abundance In Sun
~0.0000002 %
  
25
~0.0000008 %
  
20
Abundance In Earth's Crust
Abundance In Oceans
Not Available
  
Abundance In Humans
Not Available
  
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.
  
- The most common use of cesium metal is as a drilling fluid. It is also used in optical glass manufacturing.
-
In vacuum tubes and radiation monitor equipment this metal is used as a catalyst promoter.
  
Industrial Uses
Aerospace Industry, Automobile Industry, Electrical Industry, Electronic Industry
  
Aerospace Industry, Automobile Industry, Electrical Industry, Electronic Industry
  
Medical Uses
NA
  
NA
  
Other Uses
Alloys
  
Alloys
  
Biological Properties
  
  
Toxicity
Highly Toxic
  
Mildly Toxic
  
Present in Human Body
No
  
Yes
  
In Blood
Not Available
  
0.00 Blood/mg dm-3
  
28
In Bone
Not Available
  
0.05 p.p.m.
  
26
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silvery Bluish-Gray
  
Silvery Gold
  
Luster
Metallic
  
NA
  
Hardness
  
  
Brinell Hardness
3,490.00 MPa
  
1
Speed of Sound
4,940.00 m/s
  
11
Not Available
  
Optical Properties
  
  
Allotropes
No
  
No
  
α Allotropes
Not Available
  
Not Available
  
β Allotropes
Not Available
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Os
  
Cs
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Not Available
  
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
840.00 kJ/mol
  
12
375.70 kJ/mol
  
99+
2nd Energy Level
1,309.80 kJ/mol
  
99+
2,234.30 kJ/mol
  
8
3rd Energy Level
1,600.00 kJ/mol
  
99+
3,400.00 kJ/mol
  
16
Electrochemical Equivalent
1.77 g/amp-hr
  
38
4.96 g/amp-hr
  
3
Other Chemical Properties
Chemical Stability, Ionization, Solubility
  
Chemical Stability, Corrosion, Ionization, Radioactive Isotopes, Solubility
  
Electron Configuration
[Xe] 4f14 5d6 6s2
  
[Xe] 6s1
  
Crystal Structure
Hexagonal Close Packed (HCP)
  
Body Centered Cubic (BCC)
  
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
  
BCC-Crystal-Structure-.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Covalent Radius
Not Available
  
Atomic Weight
132.91 amu
  
99+
Atomic Volume
8.49 cm3/mol
  
99+
71.07 cm3/mol
  
1
Adjacent Atomic Numbers
  
  
Valence Electron Potential
91.40 (-eV)
  
12
8.62 (-eV)
  
99+
Lattice Angles
π/2, π/2, 2 π/3
  
π/2, π/2, π/2
  
Lattice C/A Ratio
Not Available
  
Density
  
  
Density At Room Temperature
1.93 g/cm3
  
99+
Density When Liquid (at m.p.)
1.84 g/cm3
  
99+
Tensile Strength
1,000.00 MPa
  
4
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Vapor Pressure at 2000 K
Not Available
  
Elasticity properties
  
  
Shear Modulus
Not Available
  
Young's Modulus
Not Available
  
Poisson Ratio
Not Available
  
Other Mechanical Properties
Ductile
  
Ductile
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Semiconductor
  
Resistivity
205.00 nΩ·m
  
17
Electrical Conductivity
0.11 106/cm Ω
  
18
0.05 106/cm Ω
  
35
Electron Affinity
106.10 kJ/mol
  
9
45.50 kJ/mol
  
25
Specific Heat
0.13 J/(kg K)
  
39
0.24 J/(kg K)
  
23
Molar Heat Capacity
24.70 J/mol·K
  
99+
32.21 J/mol·K
  
4
Thermal Conductivity
87.60 W/m·K
  
19
35.90 W/m·K
  
36
Critical Temperature
Not Available
  
Thermal Expansion
5.10 µm/(m·K)
  
99+
97.00 µm/(m·K)
  
1
Enthalpy
  
  
Enthalpy of Vaporization
627.60 kJ/mol
  
7
65.90 kJ/mol
  
99+
Enthalpy of Fusion
29.30 kJ/mol
  
4
2.10 kJ/mol
  
99+
Enthalpy of Atomization
669.00 kJ/mol
  
6
78.20 kJ/mol
  
99+
Standard Molar Entropy
32.60 J/mol.K
  
99+
85.20 J/mol.K
  
3