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Polonium Hafnium Comparison


Hafnium Polonium comparison


Periodic Table

Symbol
Po   
Hf   

Group Number
16   
2
4   
14

Period Number
6   
6   

Block
p block   
d block   

Element Family
Post-​Transition   
Transition Metal   

CAS Number
7440086   
99+
7440586   
30

Space Group Name
Pm-3m   
P63/mmc   

Space Group Number
221.00   
3
194.00   
5

Facts

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.
  
  • Hafnium metal is highly reactive, hence not found free in nature.
  • Hafnium metal as predicated after Mendeleev finished his periodic table.
  

Sources
Mining, Ores of metals   
By-product Zirconium Refining   

History
  
  

Who Discovered
Pierre Curie and Marie Curie   
Dirk Coster and George de Hevesy   

Discovery
In 1898   
In 1922   

Abundance
  
  

Abundance In Universe
Not Available   
7 * 10-8 %   
25

Abundance In Sun
~-9999 %   
~0.0000001 %   
26

Abundance In Meteorites
Not Available   
0.00 %   
37

Abundance In Earth's Crust
Not Available   
0.00 %   
31

Abundance In Oceans
0.00 %   
99+
0.00 %   
27

Uses

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.
  
  • 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, Ammunition 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   

In Blood
0.00 Blood/mg dm-3   
37
Not Available   

In Bone
0.00 p.p.m.   
36
Not Available   

Physical Properties

Melting Point
254.00 °C   
99+
2,150.00 °C   
10

Boiling Point
962.00 °C   
99+
5,400.00 °C   
5

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silver   
Gray   

Luster
NA   
Metallic   

Hardness
  
  

Mohs Hardness
Not Available   
5.50   
7

Brinell Hardness
Not Available   
1,450.00 MPa   
6

Vickers Hardness
Not Available   
1,520.00 MPa   
5

Speed of Sound
Not Available   
3,010.00 m/s   
27

Optical Properties
  
  

Allotropes
Yes   
No   

α Allotropes
α-polonium   
Not Available   

β Allotropes
β-polonium   
Not Available   

γ Allotropes
Not Available   
Not Available   

Chemical Properties

Chemical Formula
Po   
Hf   

Isotopes
  
  

Known Isotopes
29   
10
32   
7

Electronegativity
  
  

Pauling Electronegativity
2.00   
7
1.30   
32

Allred Rochow Electronegativity
1.76   
2
1.23   
25

Mulliken-Jaffe Electronegativity
2.48   
1
Not Available   

Allen Electronegativity
2.19   
2
1.16   
37

Electropositivity
  
  

Pauling Electropositivity
2.00   
99+
2.70   
22

Ionization Energies
  
  

1st Energy Level
812.10 kJ/mol   
14
658.50 kJ/mol   
40

2nd Energy Level
Not Available   
1,440.00 kJ/mol   
99+

3rd Energy Level
Not Available   
2,250.00 kJ/mol   
99+

4th Energy Level
Not Available   
3,216.00 kJ/mol   
99+

Electrochemical Equivalent
3.90 g/amp-hr   
8
1.66 g/amp-hr   
99+

Electron Work Function
Not Available   
3.90 eV   
27

Other Chemical Properties
Ionization, Radioactive Isotopes, Solubility   
Anti Corrosion, Ionization, Radioactive Isotopes, Solubility   

Atomic Properties

Atomic Number
84   
32
72   
99+

Electron Configuration
[Xe] 4f14 5d10 6s2 6p4   
[Xe] 4f14 5d2 6s2   

Crystal Structure
Monoclinic (MON)   
Hexagonal Close Packed (HCP)   

Crystal Lattice
MON-Crystal-Structure-of-Polonium.jpg#100   
BCC-Crystal-Structure-.jpg#100   

Atom
  
  

Number of Protons
84   
32
72   
99+

Number of Neutrons
125   
19
106   
29

Number of Electrons
84   
32
72   
99+

Radius of an Atom
  
  

Atomic Radius
168.00 pm   
23
159.00 pm   
28

Covalent Radius
140.00 pm   
99+
175.00 pm   
23

Van der Waals Radius
197.00 pm   
29
200.00 pm   
28

Atomic Weight
209.00 amu   
28
178.49 amu   
39

Atomic Volume
22.23 cm3/mol   
13
13.60 cm3/mol   
38

Adjacent Atomic Numbers
  
  

Previous Element
Bismuth
  
Lutetium
  

Next Element
Francium
  
Tantalum
  

Valence Electron Potential
Not Available   
81.00 (-eV)   
16

Lattice Constant
335.90 pm   
99+
319.64 pm   
99+

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

Lattice C/A Ratio
Not Available   
1.58   
12

Mechanical Properties

Density
  
  

Density At Room Temperature
9.20 g/cm3   
99+
13.31 g/cm3   
26

Density When Liquid (at m.p.)
9.40 g/cm3   
19
12.00 g/cm3   
12

Tensile Strength
Not Available   
445.00 MPa   
8

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Vapor Pressure at 2000 K
Not Available   
0.00 (Pa)   
24

Elasticity properties
  
  

Shear Modulus
Not Available   
30.00 GPa   
23

Bulk Modulus
Not Available   
110.00 GPa   
15

Young's Modulus
Not Available   
78.00 GPa   
25

Poisson Ratio
Not Available   
0.37   
7

Other Mechanical Properties
NA   
Ductile, Malleable   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
9.32   
31
13.31   
18

Magnetic Ordering
Nonmagnetic   
Paramagnetic   

Electrical Properties
  
  

Electrical Property
Conductor   
Conductor   

Resistivity
0.40 nΩ·m   
99+
331.00 nΩ·m   
14

Electrical Conductivity
0.02 106/cm Ω   
99+
0.03 106/cm Ω   
39

Electron Affinity
183.30 kJ/mol   
3
0.00 kJ/mol   
40

Thermal Properties

Specific Heat
0.12 J/(kg K)   
40
0.14 J/(kg K)   
37

Molar Heat Capacity
26.40 J/mol·K   
28
25.73 J/mol·K   
36

Thermal Conductivity
20.00 W/m·K   
99+
23.00 W/m·K   
99+

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
23.50 µm/(m·K)   
16
5.90 µm/(m·K)   
99+

Enthalpy
  
  

Enthalpy of Vaporization
60.30 kJ/mol   
99+
661.10 kJ/mol   
5

Enthalpy of Fusion
13.00 kJ/mol   
26
25.10 kJ/mol   
8

Enthalpy of Atomization
134.00 kJ/mol   
99+
703.00 kJ/mol   
5

Standard Molar Entropy
Not Available   
43.60 J/mol.K   
34

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