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Neptunium vs Hafnium

Neptunium
Hafnium
Hafnium vs Neptunium


Periodic Table
Symbol
Np   
Hf   
Group Number
Not Available   
4   
14
Period Number
7   
6   
Block
f block   
d block   
Element Family
Actinide   
Transition Metal   
CAS Number
7439998   
99+
7440586   
30
Space Group Name
Pnma   
P63/mmc   
Space Group Number
62.00   
11
194.00   
5
Facts
Interesting Facts
Not Available   
  • Hafnium metal is highly reactive, hence not found free in nature.
  • Hafnium metal as predicated after Mendeleev finished his periodic table.
  
Sources
Made by Bombarding Uranium with Neutrons, Ores of metals   
By-product Zirconium Refining   
History
  
  
Who Discovered
Edwin McMillan and Philip H. Abelson   
Dirk Coster and George de Hevesy   
Discovery
In 1940   
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
Not Available   
0.00 %   
27
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.
  
  • 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
NA   
Ammunition Industry   
Medical Uses
NA   
NA   
Other Uses
Alloys, Nuclear Research, Research Purposes   
Alloys, In Nuclear Reactors, Nuclear Research, Research Purposes   
Biological Properties
  
  
Toxicity
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
640.00 °C   
99+
2,150.00 °C   
10
Boiling Point
3,902.00 °C   
13
5,400.00 °C   
5
Appearance
  
  
Physical State
Solid   
Solid   
Color
Silver   
Gray   
Luster
Metallic   
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
No   
No   
α Allotropes
Not Available   
Not Available   
β Allotropes
Not Available   
Not Available   
γ Allotropes
Not Available   
Not Available   
Chemical Properties
Chemical Formula
Np   
Hf   
Isotopes
  
  
Known Isotopes
20   
19
32   
7
Electronegativity
  
  
Pauling Electronegativity
1.36   
29
1.30   
32
Allred Rochow Electronegativity
1.22   
26
1.23   
25
Allen Electronegativity
Not Available   
1.16   
37
Electropositivity
  
  
Pauling Electropositivity
2.64   
25
2.70   
22
Ionization Energies
  
  
1st Energy Level
604.50 kJ/mol   
99+
658.50 kJ/mol   
40
2nd Energy Level
1,128.00 kJ/mol   
99+
1,440.00 kJ/mol   
99+
3rd Energy Level
1,997.00 kJ/mol   
99+
2,250.00 kJ/mol   
99+
4th Energy Level
3,242.00 kJ/mol   
99+
3,216.00 kJ/mol   
99+
Electrochemical Equivalent
1.77 g/amp-hr   
39
1.66 g/amp-hr   
99+
Electron Work Function
Not Available   
3.90 eV   
27
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity, Solubility   
Anti Corrosion, Ionization, Radioactive Isotopes, Solubility   
Atomic Properties
Atomic Number
93   
25
72   
99+
Electron Configuration
[Rn] 5f4 6d1 7s2   
[Xe] 4f14 5d2 6s2   
Crystal Structure
Orthorhombic (ORTH)   
Hexagonal Close Packed (HCP)   
Crystal Lattice
ORTH-Crystal-Structure-of-Neptunium.jpg#100   
BCC-Crystal-Structure-.jpg#100   
Atom
  
  
Number of Protons
93   
25
72   
99+
Number of Neutrons
144   
14
106   
29
Number of Electrons
93   
25
72   
99+
Radius of an Atom
  
  
Atomic Radius
155.00 pm   
30
159.00 pm   
28
Covalent Radius
190.00 pm   
18
175.00 pm   
23
Van der Waals Radius
221.00 pm   
22
200.00 pm   
28
Atomic Weight
237.00 amu   
22
178.49 amu   
39
Atomic Volume
11.62 cm3/mol   
99+
13.60 cm3/mol   
38
Adjacent Atomic Numbers
  
  
Previous Element
Uranium
  
Lutetium
  
Next Element
Plutonium
  
Tantalum
  
Valence Electron Potential
96.00 (-eV)   
9
81.00 (-eV)   
16
Lattice Constant
666.30 pm   
3
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
19.38 g/cm3   
14
13.31 g/cm3   
26
Density When Liquid (at m.p.)
Not Available   
12.00 g/cm3   
12
Tensile Strength
125.00 MPa   
14
445.00 MPa   
8
Viscosity
Not Available   
Not Available   
Vapor Pressure
  
  
Vapor Pressure at 2000 K
0.11 (Pa)   
17
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
Ductile   
Ductile, Malleable   
Magnetic Properties
Magnetic Characteristics
  
  
Specific Gravity
20.25   
6
13.31   
18
Magnetic Ordering
Paramagnetic   
Paramagnetic   
Electrical Properties
  
  
Electrical Property
Conductor   
Conductor   
Resistivity
1.22 nΩ·m   
99+
331.00 nΩ·m   
14
Electrical Conductivity
0.01 106/cm Ω   
99+
0.03 106/cm Ω   
39
Electron Affinity
Not Available   
0.00 kJ/mol   
40
Thermal Properties
Specific Heat
0.12 J/(kg K)   
40
0.14 J/(kg K)   
37
Molar Heat Capacity
29.46 J/mol·K   
8
25.73 J/mol·K   
36
Thermal Conductivity
6.30 W/m·K   
99+
23.00 W/m·K   
99+
Critical Temperature
Not Available   
Not Available   
Thermal Expansion
Not Available   
5.90 µm/(m·K)   
99+
Enthalpy
  
  
Enthalpy of Vaporization
Not Available   
661.10 kJ/mol   
5
Enthalpy of Fusion
3.20 kJ/mol   
99+
25.10 kJ/mol   
8
Enthalpy of Atomization
Not Available   
703.00 kJ/mol   
5
Standard Molar Entropy
Not Available   
43.60 J/mol.K   
34
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