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Protactinium vs Neptunium

Protactinium
Neptunium
Neptunium vs Protactinium


Periodic Table
Symbol
Pa   
Np   
Group Number
Not Available   
Not Available   
Period Number
7   
7   
Block
f block   
f block   
Element Family
Actinide   
Actinide   
CAS Number
7440133   
99+
7439998   
99+
Space Group Name
I4/mmm   
Pnma   
Space Group Number
139.00   
8
62.00   
11
Facts
Interesting Facts
  • Protactinium metal has 29 isotopes.
  • Isotopes of Protactinium-231 used in nuclear weapon.
  
Not Available   
Sources
Found in Uranium Ores, Mining, Ores of metals   
Made by Bombarding Uranium with Neutrons, Ores of metals   
History
  
  
Who Discovered
William Crookes   
Edwin McMillan and Philip H. Abelson   
Discovery
In 1900   
In 1940   
Abundance
  
  
Abundance In Earth's Crust
0.00 %   
99+
Not Available   
Abundance In Oceans
0.00 %   
99+
Not Available   
Uses
Uses & Benefits
  • Currently known uses of Protactinium metal are limited to research purpose only.
  
  • 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
NA   
NA   
Medical Uses
NA   
NA   
Other Uses
NA   
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
1,568.00 °C   
21
640.00 °C   
99+
Boiling Point
4,027.00 °C   
12
3,902.00 °C   
13
Appearance
  
  
Physical State
Solid   
Solid   
Color
Silver   
Silver   
Luster
Metallic   
Metallic   
Hardness
  
  
Speed of Sound
Not Available   
Not Available   
Optical Properties
  
  
Allotropes
No   
No   
α Allotropes
Not Available   
Not Available   
β Allotropes
Not Available   
Not Available   
γ Allotropes
Not Available   
Not Available   
Chemical Properties
Chemical Formula
Pa   
Np   
Isotopes
  
  
Known Isotopes
27   
12
20   
19
Electronegativity
  
  
Pauling Electronegativity
1.50   
27
1.36   
29
Allred Rochow Electronegativity
1.14   
28
1.22   
26
Electropositivity
  
  
Pauling Electropositivity
2.50   
27
2.64   
25
Ionization Energies
  
  
1st Energy Level
568.00 kJ/mol   
99+
604.50 kJ/mol   
99+
2nd Energy Level
1,128.00 kJ/mol   
99+
1,128.00 kJ/mol   
99+
3rd Energy Level
1,814.00 kJ/mol   
99+
1,997.00 kJ/mol   
99+
4th Energy Level
2,991.00 kJ/mol   
99+
3,242.00 kJ/mol   
99+
Electrochemical Equivalent
1.72 g/amp-hr   
99+
1.77 g/amp-hr   
39
Electron Work Function
Not Available   
Not Available   
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity   
Ionization, Radioactive Isotopes, Radioactivity, Solubility   
Atomic Properties
Atomic Number
91   
27
93   
25
Electron Configuration
[Rn] 5f2 6d1 7s2   
[Rn] 5f4 6d1 7s2   
Crystal Structure
Tetragonal (TETR)   
Orthorhombic (ORTH)   
Crystal Lattice
TETR-Crystal-Structure-of-Protactinium.jpg#100   
ORTH-Crystal-Structure-of-Neptunium.jpg#100   
Atom
  
  
Number of Protons
91   
27
93   
25
Number of Neutrons
122   
21
144   
14
Number of Electrons
91   
27
93   
25
Radius of an Atom
  
  
Atomic Radius
163.00 pm   
25
155.00 pm   
30
Covalent Radius
200.00 pm   
11
190.00 pm   
18
Van der Waals Radius
243.00 pm   
11
221.00 pm   
22
Atomic Weight
231.04 amu   
24
237.00 amu   
22
Atomic Volume
15.00 cm3/mol   
34
11.62 cm3/mol   
99+
Adjacent Atomic Numbers
  
  
Previous Element
Thorium
  
Uranium
  
Next Element
Uranium
  
Plutonium
  
Valence Electron Potential
92.00 (-eV)   
11
96.00 (-eV)   
9
Lattice Constant
392.50 pm   
23
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
15.37 g/cm3   
20
19.38 g/cm3   
14
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
Unknown   
Ductile   
Magnetic Properties
Magnetic Characteristics
  
  
Specific Gravity
15.37   
12
20.25   
6
Magnetic Ordering
Paramagnetic   
Paramagnetic   
Electrical Properties
  
  
Electrical Property
Conductor   
Conductor   
Resistivity
177.00 nΩ·m   
21
1.22 nΩ·m   
99+
Electrical Conductivity
0.05 106/cm Ω   
34
0.01 106/cm Ω   
99+
Thermal Properties
Specific Heat
0.12 J/(kg K)   
40
0.12 J/(kg K)   
40
Molar Heat Capacity
Not Available   
29.46 J/mol·K   
8
Thermal Conductivity
47.00 W/m·K   
32
6.30 W/m·K   
99+
Critical Temperature
Not Available   
Not Available   
Thermal Expansion
9.90 µm/(m·K)   
40
Not Available   
Enthalpy
  
  
Enthalpy of Fusion
12.34 kJ/mol   
28
3.20 kJ/mol   
99+
Standard Molar Entropy
198.10 J/mol.K   
1
Not Available   
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