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Neptunium vs Polonium

Neptunium
Polonium
Polonium vs Neptunium


Periodic Table
Symbol
Np  
Po  
Group Number
3  
15
16  
2
Period Number
7  
6  
Block
f block  
p block  
Element Family
Actinide  
Post-​Transition  
CAS Number
7439998  
99+
7440086  
99+
Space Group Name
Pnma  
Pm-3m  
Space Group Number
62.00  
14
221.00  
4
Facts
Interesting Facts
Neptunium was the first transuranium element to be discovered.  
  • 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
Made by Bombarding Uranium with Neutrons, Ores of metals  
Mining, Ores of metals  
History
  
  
Who Discovered
Edwin McMillan and Philip H. Abelson  
Pierre Curie and Marie Curie  
Discovery
In 1940  
In 1898  
Abundance
  
  
Abundance In Universe
0.00 %  
40
0.00 %  
40
Abundance In Sun
0.00 %  
26
-  
Abundance In Meteorites
0.00 %  
99+
-  
Abundance In Earth's Crust
0.00 %  
99+
0.00 %  
99+
Abundance In Oceans
-  
0.00 %  
99+
Abundance In Humans
0.00 %  
24
0.00 %  
24
Uses
Uses & Benefits
  • Currently known uses of Neptunium metal are limited to research purpose only.
  • Neptunium’s isotope neptunium-237 is used as a neutron detectors.
  
  • 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, Ammunition Industry  
Medical Uses
-  
-  
Other Uses
Alloys, Nuclear Research, Research Purposes  
Alloys  
Biological Properties
  
  
Toxicity
Toxic  
Highly Toxic  
Present in Human Body
No  
No  
In Blood
0.00 Blood/mg dm-3  
40
0.00 Blood/mg dm-3  
40
In Bone
0.00 p.p.m.  
99+
0.00 p.p.m.  
99+
Physical
Melting Point
640.00 °C  
99+
254.00 °C  
99+
Boiling Point
3,902.00 °C  
13
962.00 °C  
99+
Appearance
  
  
Physical State
Solid  
Solid  
Color
Silver  
Silver  
Luster
Metallic  
-  
Hardness
  
  
Mohs Hardness
6.00  
6
2.50  
15
Brinell Hardness
622.00 MPa  
23
70.00 MPa  
99+
Vickers Hardness
640.00 MPa  
23
30.00 MPa  
99+
Speed of Sound
2,260.00 m/s  
99+
2,260.00 m/s  
99+
Optical Properties
  
  
Refractive Index
1.30  
99+
2.70  
3
Reflectivity
64.00 %  
19
50.00 %  
31
Allotropes
No  
Yes  
α Allotropes
-  
α-polonium  
β Allotropes
-  
β-polonium  
γ Allotropes
-  
-  
Chemical
Chemical Formula
Np  
Po  
Isotopes
  
  
Known Isotopes
20  
19
29  
10
Electronegativity
  
  
Pauling Electronegativity
1.36  
30
2.00  
8
Sanderson Electronegativity
1.36  
23
2.00  
10
Allred Rochow Electronegativity
1.22  
27
1.76  
3
Mulliken-Jaffe Electronegativity
1.36  
31
2.48  
1
Allen Electronegativity
1.36  
37
2.19  
2
Electropositivity
  
  
Pauling Electropositivity
2.64  
25
2.00  
99+
Ionization Energies
  
  
1st Energy Level
604.50 kJ/mol  
99+
812.10 kJ/mol  
14
2nd Energy Level
1,128.00 kJ/mol  
99+
1,833.20 kJ/mol  
17
3rd Energy Level
1,997.00 kJ/mol  
99+
812.10 kJ/mol  
99+
4th Energy Level
3,242.00 kJ/mol  
99+
8,121.00 kJ/mol  
7
5th Energy Level
6,180.00 kJ/mol  
99+
8,120.00 kJ/mol  
12
6th Energy Level
5,785.00 kJ/mol  
99+
8,120.00 kJ/mol  
32
7th Energy level
6,040.00 kJ/mol  
99+
8,120.00 kJ/mol  
26
8th Energy Level
6,040.00 kJ/mol  
99+
8,120.00 kJ/mol  
26
9th Energy Level
6,180.00 kJ/mol  
99+
8,120.00 kJ/mol  
23
10th Energy Level
6,180.00 kJ/mol  
99+
8,120.00 kJ/mol  
27
11th Energy Level
6,180.00 kJ/mol  
99+
8,120.00 kJ/mol  
26
12th Energy Level
61,800.00 kJ/mol  
13
8,120.00 kJ/mol  
99+
13th Energy Level
6,180.00 kJ/mol  
40
8,120.00 kJ/mol  
19
14th Energy Level
6,180.00 kJ/mol  
29
8,120.00 kJ/mol  
18
15th Energy Level
60,600.00 kJ/mol  
99+
81,200.00 kJ/mol  
15
16th Energy Level
60,420.00 kJ/mol  
31
81,200.00 kJ/mol  
12
17th Energy Level
604.00 kJ/mol  
99+
812.10 kJ/mol  
32
18th Energy Level
6,040.00 kJ/mol  
99+
8,120.00 kJ/mol  
21
19th Energy Level
604.50 kJ/mol  
99+
812.10 kJ/mol  
29
20th Energy Level
604.00 kJ/mol  
99+
812.00 kJ/mol  
22
21st Energy Level
6,040.00 kJ/mol  
17
812.10 kJ/mol  
40
22nd Energy Level
604.00 kJ/mol  
40
812.00 kJ/mol  
17
23rd Energy Level
6,040.00 kJ/mol  
18
812.10 kJ/mol  
99+
24th Energy Level
604.50 kJ/mol  
99+
812.10 kJ/mol  
13
25th Energy Level
604.00 kJ/mol  
99+
812.10 kJ/mol  
11
26th Energy Level
604.00 kJ/mol  
99+
812.10 kJ/mol  
11
27th Energy Level
604.00 kJ/mol  
99+
812.10 kJ/mol  
10
28th Energy Level
604.00 kJ/mol  
99+
812.10 kJ/mol  
16
29th Energy Level
604.00 kJ/mol  
99+
812.10 kJ/mol  
15
30th Energy Level
604.00 kJ/mol  
99+
812.00 kJ/mol  
11
Electrochemical Equivalent
1.77 g/amp-hr  
99+
3.90 g/amp-hr  
8
Electron Work Function
4.90 eV  
12
4.50 eV  
19
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity, Solubility  
Ionization, Radioactive Isotopes, Solubility  
Atomic
Atomic Number
93  
25
84  
32
Electron Configuration
[Rn] 5f4 6d1 7s2  
[Xe] 4f14 5d10 6s2 6p4  
Crystal Structure
Orthorhombic (ORTH)  
Monoclinic (MON)  
Crystal Lattice
ORTH-Crystal-Structure-of-Neptunium.jpg#100  
MON-Crystal-Structure-of-Polonium.jpg#100  
Atom
  
  
Number of Protons
93  
25
84  
32
Number of Neutrons
144  
15
125  
20
Number of Electrons
93  
25
84  
32
Radius of an Atom
  
  
Atomic Radius
155.00 pm  
32
168.00 pm  
25
Covalent Radius
190.00 pm  
18
140.00 pm  
99+
Van der Waals Radius
221.00 pm  
27
197.00 pm  
36
Atomic Weight
237.00 amu  
22
209.00 amu  
28
Atomic Volume
11.62 cm3/mol  
99+
22.23 cm3/mol  
22
Adjacent Atomic Numbers
  
  
Previous Element
Uranium
  
Bismuth
  
Next Element
Plutonium
  
Francium
  
Valence Electron Potential
96.00 (-eV)  
9
9.30 (-eV)  
99+
Lattice Constant
666.30 pm  
3
335.90 pm  
99+
Lattice Angles
π/2, π/2, π/2  
π/2, π/2, π/2  
Lattice C/A Ratio
1.43  
99+
1.46  
99+
Mechanical
Density
  
  
Density At Room Temperature
19.38 g/cm3  
14
9.20 g/cm3  
99+
Density When Liquid (at m.p.)
20.25 g/cm3  
10
9.40 g/cm3  
99+
Tensile Strength
125.00 MPa  
26
50.00 MPa  
38
Viscosity
0.00  
25
0.00  
26
Vapor Pressure
  
  
Vapor Pressure at 1000 K
0.00 (Pa)  
22
0.00 (Pa)  
37
Vapor Pressure at 2000 K
0.11 (Pa)  
17
0.00 (Pa)  
37
Elasticity properties
  
  
Shear Modulus
5.60 GPa  
99+
24.00 GPa  
40
Bulk Modulus
180.00 GPa  
9
46.00 GPa  
28
Young's Modulus
46.00 GPa  
99+
46.00 GPa  
99+
Poisson Ratio
0.26  
22
0.23  
30
Other Mechanical Properties
Ductile  
-  
Magnetic
Magnetic Characteristics
  
  
Specific Gravity
20.25  
15
9.32  
99+
Magnetic Ordering
Paramagnetic  
Nonmagnetic  
Permeability
0.00 H/m  
6
0.00 H/m  
15
Susceptibility
0.00  
24
0.00  
24
Electrical Properties
  
  
Electrical Property
Conductor  
Conductor  
Resistivity
1.22 nΩ·m  
99+
0.40 nΩ·m  
99+
Electrical Conductivity
0.01 106/cm Ω  
99+
0.02 106/cm Ω  
99+
Electron Affinity
118.60 kJ/mol  
6
183.30 kJ/mol  
3
Thermal
Specific Heat
0.12 J/(kg K)  
99+
0.12 J/(kg K)  
99+
Molar Heat Capacity
29.46 J/mol·K  
10
26.40 J/mol·K  
36
Thermal Conductivity
6.30 W/m·K  
99+
20.00 W/m·K  
99+
Critical Temperature
913.00 K  
99+
527.00 K  
99+
Thermal Expansion
13.30 µm/(m·K)  
35
23.50 µm/(m·K)  
16
Enthalpy
  
  
Enthalpy of Vaporization
336.00 kJ/mol  
39
60.30 kJ/mol  
99+
Enthalpy of Fusion
3.20 kJ/mol  
99+
13.00 kJ/mol  
32
Enthalpy of Atomization
275.30 kJ/mol  
99+
134.00 kJ/mol  
99+
Standard Molar Entropy
64.00 J/mol.K  
21
41.10 J/mol.K  
99+
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