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Polonium vs Neptunium


Neptunium vs Polonium


Periodic Table

Symbol
Po   
Np   

Group Number
16   
2
Not Available   

Period Number
6   
7   

Block
p block   
f block   

Element Family
Post-​Transition   
Actinide   

CAS Number
7440086   
99+
7439998   
99+

Space Group Name
Pm-3m   
Pnma   

Space Group Number
221.00   
3
62.00   
11

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.
  
Not Available   

Sources
Mining, Ores of metals   
Made by Bombarding Uranium with Neutrons, Ores of metals   

History
  
  

Who Discovered
Pierre Curie and Marie Curie   
Edwin McMillan and Philip H. Abelson   

Discovery
In 1898   
In 1940   

Abundance
  
  

Abundance In Oceans
0.00 %   
99+
Not Available   

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.
  
  • Currently known uses of Neptunium metal are limited to research purpose only.
  • Neptunium’s isotope neptunium-237 is used as a neutron detectors.
  

Industrial Uses
Aerospace Industry, Ammunition Industry   
NA   

Medical Uses
NA   
NA   

Other Uses
Alloys   
Alloys, 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
0.00 Blood/mg dm-3   
37

In Bone
0.00 p.p.m.   
36
0.00 p.p.m.   
36

Physical Properties

Melting Point
254.00 °C   
99+
640.00 °C   
99+

Boiling Point
962.00 °C   
99+
3,902.00 °C   
13

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silver   
Silver   

Luster
NA   
Metallic   

Hardness
  
  

Speed of Sound
Not Available   
Not Available   

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   
Np   

Isotopes
  
  

Known Isotopes
29   
10
20   
19

Electronegativity
  
  

Pauling Electronegativity
2.00   
7
1.36   
29

Allred Rochow Electronegativity
1.76   
2
1.22   
26

Mulliken-Jaffe Electronegativity
2.48   
1
Not Available   

Allen Electronegativity
2.19   
2
Not Available   

Electropositivity
  
  

Pauling Electropositivity
2.00   
99+
2.64   
25

Ionization Energies
  
  

1st Energy Level
812.10 kJ/mol   
14
604.50 kJ/mol   
99+

2nd Energy Level
Not Available   
1,128.00 kJ/mol   
99+

3rd Energy Level
Not Available   
1,997.00 kJ/mol   
99+

4th Energy Level
Not Available   
3,242.00 kJ/mol   
99+

Electrochemical Equivalent
3.90 g/amp-hr   
8
1.77 g/amp-hr   
39

Electron Work Function
Not Available   
Not Available   

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

Atomic Properties

Atomic Number
84   
32
93   
25

Electron Configuration
[Xe] 4f14 5d10 6s2 6p4   
[Rn] 5f4 6d1 7s2   

Crystal Structure
Monoclinic (MON)   
Orthorhombic (ORTH)   

Crystal Lattice
MON-Crystal-Structure-of-Polonium.jpg#100   
ORTH-Crystal-Structure-of-Neptunium.jpg#100   

Atom
  
  

Number of Protons
84   
32
93   
25

Number of Neutrons
125   
19
144   
14

Number of Electrons
84   
32
93   
25

Radius of an Atom
  
  

Atomic Radius
168.00 pm   
23
155.00 pm   
30

Covalent Radius
140.00 pm   
99+
190.00 pm   
18

Van der Waals Radius
197.00 pm   
29
221.00 pm   
22

Atomic Weight
209.00 amu   
28
237.00 amu   
22

Atomic Volume
22.23 cm3/mol   
13
11.62 cm3/mol   
99+

Adjacent Atomic Numbers
  
  

Previous Element
Bismuth
  
Uranium
  

Next Element
Francium
  
Plutonium
  

Valence Electron Potential
Not Available   
96.00 (-eV)   
9

Lattice Constant
335.90 pm   
99+
666.30 pm   
3

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

Lattice C/A Ratio
Not Available   
Not Available   

Mechanical Properties

Density
  
  

Density At Room Temperature
9.20 g/cm3   
99+
19.38 g/cm3   
14

Density When Liquid (at m.p.)
9.40 g/cm3   
19
Not Available   

Tensile Strength
Not Available   
125.00 MPa   
14

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Vapor Pressure at 2000 K
Not Available   
0.11 (Pa)   
17

Elasticity properties
  
  

Poisson Ratio
Not Available   
Not Available   

Other Mechanical Properties
NA   
Ductile   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
9.32   
31
20.25   
6

Magnetic Ordering
Nonmagnetic   
Paramagnetic   

Electrical Properties
  
  

Electrical Property
Conductor   
Conductor   

Resistivity
0.40 nΩ·m   
99+
1.22 nΩ·m   
99+

Electrical Conductivity
0.02 106/cm Ω   
99+
0.01 106/cm Ω   
99+

Electron Affinity
183.30 kJ/mol   
3
Not Available   

Thermal Properties

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

Molar Heat Capacity
26.40 J/mol·K   
28
29.46 J/mol·K   
8

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

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
23.50 µm/(m·K)   
16
Not Available   

Enthalpy
  
  

Enthalpy of Vaporization
60.30 kJ/mol   
99+
Not Available   

Enthalpy of Fusion
13.00 kJ/mol   
26
3.20 kJ/mol   
99+

Enthalpy of Atomization
134.00 kJ/mol   
99+
Not Available   

Standard Molar Entropy
Not Available   
Not Available   

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