Symbol
Po
  
Ir
  
Period Number
6
  
6
  
Block
p block
  
d block
  
Element Family
Post-Transition
  
Transition Metal
  
Space Group Name
Pm-3m
  
Fm_ 3m
  
Interesting Facts
- Polonium was the first radioactive element to be discovered.
- Polonium element and its compounds are highly radioactive.
- Its alloy with Beryllium provides source of neutrons.
  
- Iridium element occurs as natural alloys of Platinum and Osmium.
- Iridium element is known as the most corrosion resistance metal .
  
Sources
Mining, Ores of metals
  
Found in Minerals, Mining, Ores of Minerals
  
History
  
  
Who Discovered
Pierre Curie and Marie Curie
  
Smithson Tennant
  
Discovery
In 1898
  
In 1803
  
Abundance
  
  
Abundance In Universe
Not Available
  
Abundance In Sun
~-9999 %
  
~0.0000002 %
  
25
Abundance In Meteorites
Not Available
  
Abundance In Earth's Crust
Not Available
  
Abundance In Oceans
Not Available
  
Uses & Benefits
- Polonium metal has different Allotropes, it is used in antistatic devices and for research purpose.
- A 1 gram of Polonium can reach a temperature of 500°C, hence it is used as a heat source for space equipment.
  
- 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, Ammunition 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
  
In Blood
0.00 Blood/mg dm-3
  
37
Not Available
  
In Bone
0.00 p.p.m.
  
36
Not Available
  
Boiling Point
4,527.00 °C
  
10
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silver
  
Silvery White
  
Luster
NA
  
Metallic
  
Hardness
  
  
Mohs Hardness
Not Available
  
Brinell Hardness
Not Available
  
1,670.00 MPa
  
5
Vickers Hardness
Not Available
  
1,760.00 MPa
  
3
Speed of Sound
Not Available
  
4,825.00 m/s
  
13
Optical Properties
  
  
Reflectivity
Not Available
  
Allotropes
Yes
  
No
  
α Allotropes
α-polonium
  
Not Available
  
β Allotropes
β-polonium
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Po
  
Ir
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
812.10 kJ/mol
  
14
880.00 kJ/mol
  
9
2nd Energy Level
Not Available
  
1,600.00 kJ/mol
  
35
Electrochemical Equivalent
3.90 g/amp-hr
  
8
1.14 g/amp-hr
  
99+
Electron Work Function
Not Available
  
Other Chemical Properties
Ionization, Radioactive Isotopes, Solubility
  
Flammable, Ionization, Radioactive Isotopes, Radioactivity
  
Electron Configuration
[Xe] 4f14 5d10 6s2 6p4
  
[Xe] 4f14 5d7 6s2
  
Crystal Structure
Monoclinic (MON)
  
Face Centered Cubic (FCC)
  
Crystal Lattice
MON-Crystal-Structure-of-Polonium.jpg#100
  
FCC-Crystal-Structure-of-Iridium.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Volume
22.23 cm3/mol
  
13
9.53 cm3/mol
  
99+
Adjacent Atomic Numbers
  
  
Valence Electron Potential
Not Available
  
140.00 (-eV)
  
5
Lattice Angles
π/2, π/2, π/2
  
π/2, π/2, π/2
  
Lattice C/A Ratio
Not Available
  
Not Available
  
Density
  
  
Density At Room Temperature
9.20 g/cm3
  
99+
22.56 g/cm3
  
10
Density When Liquid (at m.p.)
Tensile Strength
Not Available
  
2,000.00 MPa
  
2
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Vapor Pressure at 2000 K
Not Available
  
Elasticity properties
  
  
Shear Modulus
Not Available
  
Bulk Modulus
Not Available
  
Young's Modulus
Not Available
  
Poisson Ratio
Not Available
  
Other Mechanical Properties
NA
  
NA
  
Magnetic Characteristics
  
  
Magnetic Ordering
Nonmagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Conductor
  
Resistivity
47.10 nΩ·m
  
99+
Electrical Conductivity
0.02 106/cm Ω
  
99+
0.19 106/cm Ω
  
10
Electron Affinity
183.30 kJ/mol
  
3
151.00 kJ/mol
  
4
Specific Heat
0.12 J/(kg K)
  
40
0.13 J/(kg K)
  
39
Molar Heat Capacity
26.40 J/mol·K
  
28
25.10 J/mol·K
  
99+
Thermal Conductivity
20.00 W/m·K
  
99+
147.00 W/m·K
  
10
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
23.50 µm/(m·K)
  
16
6.40 µm/(m·K)
  
99+
Enthalpy
  
  
Enthalpy of Vaporization
60.30 kJ/mol
  
99+
799.10 kJ/mol
  
1
Enthalpy of Fusion
13.00 kJ/mol
  
26
35.23 kJ/mol
  
1
Enthalpy of Atomization
134.00 kJ/mol
  
99+
837.00 kJ/mol
  
1
Standard Molar Entropy
Not Available
  
35.50 J/mol.K
  
99+