Symbol
Mo
  
Po
  
Period Number
5
  
6
  
Block
d block
  
p block
  
Element Family
Transition Metal
  
Post-Transition
  
Space Group Name
Im_ 3m
  
Pm-3m
  
Interesting Facts
- Molybdenum is highly reactive metal, hence not found free in nature .
- Till 18th century Molybdenum element were often mistaken as a carbon or Lead.
  
- 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.
  
Sources
Found in Minerals, Mining, Ores of Minerals
  
Mining, Ores of metals
  
History
  
  
Who Discovered
Carl Wilhelm Scheele
  
Pierre Curie and Marie Curie
  
Discovery
In 1778
  
In 1898
  
Abundance
  
  
Abundance In Universe
Not Available
  
Abundance In Sun
~0.0000009 %
  
19
~-9999 %
  
Abundance In Meteorites
Not Available
  
Abundance In Earth's Crust
Not Available
  
Abundance In Humans
Not Available
  
Uses & Benefits
- Its alloys are used to make engine parts, drills, saw blade, etc.
- Lubricant additive made up of Molybdenum disulfide is commonly used in the industry. It is also used as a catalyst.
  
- 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.
  
Industrial Uses
Aerospace Industry, Electrical Industry, Electronic Industry
  
Aerospace Industry, Ammunition Industry
  
Medical Uses
NA
  
NA
  
Other Uses
Alloys
  
Alloys
  
Biological Properties
  
  
Toxicity
Toxic
  
Highly Toxic
  
Present in Human Body
Yes
  
No
  
In Blood
0.00 Blood/mg dm-3
  
31
0.00 Blood/mg dm-3
  
37
In Bone
0.70 p.p.m.
  
18
0.00 p.p.m.
  
36
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Gray
  
Silver
  
Luster
Metallic
  
NA
  
Hardness
  
  
Mohs Hardness
Not Available
  
Brinell Hardness
1,370.00 MPa
  
7
Not Available
  
Vickers Hardness
1,400.00 MPa
  
6
Not Available
  
Speed of Sound
5,400.00 m/s
  
6
Not Available
  
Optical Properties
  
  
Reflectivity
Not Available
  
Allotropes
No
  
Yes
  
α Allotropes
Not Available
  
α-polonium
  
β Allotropes
Not Available
  
β-polonium
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Mo
  
Po
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Not Available
  
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
684.30 kJ/mol
  
37
812.10 kJ/mol
  
14
2nd Energy Level
1,560.00 kJ/mol
  
37
Not Available
  
3rd Energy Level
2,618.00 kJ/mol
  
99+
Not Available
  
4th Energy Level
4,480.00 kJ/mol
  
26
Not Available
  
5th Energy Level
5,257.00 kJ/mol
  
32
Not Available
  
6th Energy Level
6,640.80 kJ/mol
  
22
Not Available
  
7th Energy level
12,125.00 kJ/mol
  
13
Not Available
  
8th Energy Level
13,860.00 kJ/mol
  
16
Not Available
  
9th Energy Level
15,835.00 kJ/mol
  
16
Not Available
  
10th Energy Level
17,980.00 kJ/mol
  
18
Not Available
  
11th Energy Level
20,190.00 kJ/mol
  
17
Not Available
  
12th Energy Level
22,219.00 kJ/mol
  
15
Not Available
  
13th Energy Level
26,930.00 kJ/mol
  
13
Not Available
  
14th Energy Level
29,196.00 kJ/mol
  
13
Not Available
  
15th Energy Level
52,490.00 kJ/mol
  
7
Not Available
  
16th Energy Level
55,000.00 kJ/mol
  
8
Not Available
  
17th Energy Level
61,400.00 kJ/mol
  
9
Not Available
  
18th Energy Level
67,700.00 kJ/mol
  
9
Not Available
  
19th Energy Level
74,000.00 kJ/mol
  
9
Not Available
  
20th Energy Level
80,400.00 kJ/mol
  
10
Not Available
  
21st Energy Level
87,000.00 kJ/mol
  
9
Not Available
  
22nd Energy Level
93,400.00 kJ/mol
  
7
Not Available
  
23rd Energy Level
98,420.00 kJ/mol
  
6
Not Available
  
24th Energy Level
104,400.00 kJ/mol
  
2
Not Available
  
25th Energy Level
121,900.00 kJ/mol
  
1
Not Available
  
26th Energy Level
127,700.00 kJ/mol
  
1
Not Available
  
27th Energy Level
133,800.00 kJ/mol
  
1
Not Available
  
28th Energy Level
139,800.00 kJ/mol
  
1
Not Available
  
29th Energy Level
148,100.00 kJ/mol
  
1
Not Available
  
30th Energy Level
154,500.00 kJ/mol
  
1
Not Available
  
Electrochemical Equivalent
0.89 g/amp-hr
  
99+
3.90 g/amp-hr
  
8
Electron Work Function
Not Available
  
Other Chemical Properties
Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
  
Ionization, Radioactive Isotopes, Solubility
  
Electron Configuration
[Kr] 4d5 5s1
  
[Xe] 4f14 5d10 6s2 6p4
  
Crystal Structure
Body Centered Cubic (BCC)
  
Monoclinic (MON)
  
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
  
MON-Crystal-Structure-of-Polonium.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Volume
9.40 cm3/mol
  
99+
22.23 cm3/mol
  
13
Adjacent Atomic Numbers
  
  
Valence Electron Potential
88.60 (-eV)
  
13
Not Available
  
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
10.28 g/cm3
  
36
9.20 g/cm3
  
99+
Density When Liquid (at m.p.)
Tensile Strength
Not Available
  
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
Ductile, Weldable
  
NA
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Nonmagnetic
  
Electrical Properties
  
  
Electrical Property
Semiconductor
  
Conductor
  
Resistivity
53.40 nΩ·m
  
99+
Electrical Conductivity
0.19 106/cm Ω
  
11
0.02 106/cm Ω
  
99+
Electron Affinity
71.90 kJ/mol
  
14
183.30 kJ/mol
  
3
Specific Heat
0.25 J/(kg K)
  
21
0.12 J/(kg K)
  
40
Molar Heat Capacity
24.06 J/mol·K
  
99+
26.40 J/mol·K
  
28
Thermal Conductivity
138.00 W/m·K
  
12
20.00 W/m·K
  
99+
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
4.80 µm/(m·K)
  
99+
23.50 µm/(m·K)
  
16
Enthalpy
  
  
Enthalpy of Vaporization
594.10 kJ/mol
  
8
60.30 kJ/mol
  
99+
Enthalpy of Fusion
27.61 kJ/mol
  
5
13.00 kJ/mol
  
26
Enthalpy of Atomization
653.00 kJ/mol
  
7
134.00 kJ/mol
  
99+
Standard Molar Entropy
28.70 J/mol.K
  
99+
Not Available